Add Checkstyle for constant name static final (#8060)

* check ctyle for constant field name

* check ctyle for constant field name

* check ctyle for constant field name

* check ctyle for constant field name

* check ctyle for constant field name

* check ctyle for constant field name

* check ctyle for constant field name

* check ctyle for constant field name

* check ctyle for constant field name

* merging with upstream

* review-1

* unknow changes

* unknow changes

* review-2

* merging with master

* review-2 1 changes

* review changes-2 2

* bug fix

benchmarks/src/main/java/org/apache/druid/benchmark/FlattenJSONBenchmark.java

@@ -48,7 +48,7 @@ import java.util.concurrent.TimeUnit;
 @Fork(value = 1)
 public class FlattenJSONBenchmark
 {
-  private static final int numEvents = 100000;
+  private static final int NUM_EVENTS = 100000;
 
   List<String> flatInputs;
   List<String> nestedInputs;
@@ -67,15 +67,15 @@ public class FlattenJSONBenchmark
   {
     FlattenJSONBenchmarkUtil gen = new FlattenJSONBenchmarkUtil();
     flatInputs = new ArrayList<String>();
-    for (int i = 0; i < numEvents; i++) {
+    for (int i = 0; i < NUM_EVENTS; i++) {
       flatInputs.add(gen.generateFlatEvent());
     }
     nestedInputs = new ArrayList<String>();
-    for (int i = 0; i < numEvents; i++) {
+    for (int i = 0; i < NUM_EVENTS; i++) {
       nestedInputs.add(gen.generateNestedEvent());
     }
     jqInputs = new ArrayList<String>();
-    for (int i = 0; i < numEvents; i++) {
+    for (int i = 0; i < NUM_EVENTS; i++) {
       jqInputs.add(gen.generateNestedEvent()); // reuse the same event as "nested"
     }
 
@@ -95,7 +95,7 @@ public class FlattenJSONBenchmark
     for (String s : parsed.keySet()) {
       blackhole.consume(parsed.get(s));
     }
-    flatCounter = (flatCounter + 1) % numEvents;
+    flatCounter = (flatCounter + 1) % NUM_EVENTS;
     return parsed;
   }
 
@@ -108,7 +108,7 @@ public class FlattenJSONBenchmark
     for (String s : parsed.keySet()) {
       blackhole.consume(parsed.get(s));
     }
-    nestedCounter = (nestedCounter + 1) % numEvents;
+    nestedCounter = (nestedCounter + 1) % NUM_EVENTS;
     return parsed;
   }
 
@@ -121,7 +121,7 @@ public class FlattenJSONBenchmark
     for (String s : parsed.keySet()) {
       blackhole.consume(parsed.get(s));
     }
-    jqCounter = (jqCounter + 1) % numEvents;
+    jqCounter = (jqCounter + 1) % NUM_EVENTS;
     return parsed;
   }
 
@@ -134,7 +134,7 @@ public class FlattenJSONBenchmark
     for (String s : parsed.keySet()) {
       blackhole.consume(parsed.get(s));
     }
-    nestedCounter = (nestedCounter + 1) % numEvents;
+    nestedCounter = (nestedCounter + 1) % NUM_EVENTS;
     return parsed;
   }
 
@@ -147,7 +147,7 @@ public class FlattenJSONBenchmark
     for (String s : parsed.keySet()) {
       blackhole.consume(parsed.get(s));
     }
-    nestedCounter = (nestedCounter + 1) % numEvents;
+    nestedCounter = (nestedCounter + 1) % NUM_EVENTS;
     return parsed;
   }
 

benchmarks/src/main/java/org/apache/druid/benchmark/FloatCompressionBenchmarkFileGenerator.java

@@ -46,7 +46,7 @@ public class FloatCompressionBenchmarkFileGenerator
 {
   private static final Logger log = new Logger(FloatCompressionBenchmarkFileGenerator.class);
   public static final int ROW_NUM = 5000000;
-  public static final List<CompressionStrategy> compressions =
+  public static final List<CompressionStrategy> COMPRESSIONS =
       ImmutableList.of(
           CompressionStrategy.LZ4,
           CompressionStrategy.NONE
@@ -138,7 +138,7 @@ public class FloatCompressionBenchmarkFileGenerator
 
     // create compressed files using all combinations of CompressionStrategy and FloatEncoding provided
     for (Map.Entry<String, BenchmarkColumnValueGenerator> entry : generators.entrySet()) {
-      for (CompressionStrategy compression : compressions) {
+      for (CompressionStrategy compression : COMPRESSIONS) {
         String name = entry.getKey() + "-" + compression;
         log.info("%s: ", name);
         File compFile = new File(dir, name);

benchmarks/src/main/java/org/apache/druid/benchmark/GenericIndexedBenchmark.java

@@ -62,7 +62,7 @@ public class GenericIndexedBenchmark
 {
   public static final int ITERATIONS = 10000;
 
-  static final ObjectStrategy<byte[]> byteArrayStrategy = new ObjectStrategy<byte[]>()
+  static final ObjectStrategy<byte[]> BYTE_ARRAY_STRATEGY = new ObjectStrategy<byte[]>()
   {
     @Override
     public Class<byte[]> getClazz()
@@ -108,7 +108,7 @@ public class GenericIndexedBenchmark
     GenericIndexedWriter<byte[]> genericIndexedWriter = new GenericIndexedWriter<>(
         new OffHeapMemorySegmentWriteOutMedium(),
         "genericIndexedBenchmark",
-        byteArrayStrategy
+        BYTE_ARRAY_STRATEGY
     );
     genericIndexedWriter.open();
 
@@ -132,7 +132,7 @@ public class GenericIndexedBenchmark
 
     FileChannel fileChannel = FileChannel.open(file.toPath());
     MappedByteBuffer byteBuffer = fileChannel.map(FileChannel.MapMode.READ_ONLY, 0, file.length());
-    genericIndexed = GenericIndexed.read(byteBuffer, byteArrayStrategy, SmooshedFileMapper.load(smooshDir));
+    genericIndexed = GenericIndexed.read(byteBuffer, BYTE_ARRAY_STRATEGY, SmooshedFileMapper.load(smooshDir));
   }
 
   @Setup(Level.Trial)

benchmarks/src/main/java/org/apache/druid/benchmark/IncrementalIndexRowTypeBenchmark.java

@@ -52,8 +52,8 @@ public class IncrementalIndexRowTypeBenchmark
   private IncrementalIndex incFloatIndex;
   private IncrementalIndex incStrIndex;
   private static AggregatorFactory[] aggs;
-  static final int dimensionCount = 8;
+  static final int DIMENSION_COUNT = 8;
-  static final int maxRows = 250000;
+  static final int MAX_ROWS = 250000;
 
   private ArrayList<InputRow> longRows = new ArrayList<InputRow>();
   private ArrayList<InputRow> floatRows = new ArrayList<InputRow>();
@@ -61,9 +61,9 @@ public class IncrementalIndexRowTypeBenchmark
 
 
   static {
-    final ArrayList<AggregatorFactory> ingestAggregatorFactories = new ArrayList<>(dimensionCount + 1);
+    final ArrayList<AggregatorFactory> ingestAggregatorFactories = new ArrayList<>(DIMENSION_COUNT + 1);
     ingestAggregatorFactories.add(new CountAggregatorFactory("rows"));
-    for (int i = 0; i < dimensionCount; ++i) {
+    for (int i = 0; i < DIMENSION_COUNT; ++i) {
       ingestAggregatorFactories.add(
           new LongSumAggregatorFactory(
               StringUtils.format("sumResult%s", i),
@@ -125,23 +125,23 @@ public class IncrementalIndexRowTypeBenchmark
         .setSimpleTestingIndexSchema(aggs)
         .setDeserializeComplexMetrics(false)
         .setReportParseExceptions(false)
-        .setMaxRowCount(maxRows)
+        .setMaxRowCount(MAX_ROWS)
         .buildOnheap();
   }
 
   @Setup
   public void setup()
   {
-    for (int i = 0; i < maxRows; i++) {
+    for (int i = 0; i < MAX_ROWS; i++) {
-      longRows.add(getLongRow(0, dimensionCount));
+      longRows.add(getLongRow(0, DIMENSION_COUNT));
     }
 
-    for (int i = 0; i < maxRows; i++) {
+    for (int i = 0; i < MAX_ROWS; i++) {
-      floatRows.add(getFloatRow(0, dimensionCount));
+      floatRows.add(getFloatRow(0, DIMENSION_COUNT));
     }
 
-    for (int i = 0; i < maxRows; i++) {
+    for (int i = 0; i < MAX_ROWS; i++) {
-      stringRows.add(getStringRow(0, dimensionCount));
+      stringRows.add(getStringRow(0, DIMENSION_COUNT));
     }
   }
 
@@ -156,10 +156,10 @@ public class IncrementalIndexRowTypeBenchmark
   @Benchmark
   @BenchmarkMode(Mode.AverageTime)
   @OutputTimeUnit(TimeUnit.MICROSECONDS)
-  @OperationsPerInvocation(maxRows)
+  @OperationsPerInvocation(MAX_ROWS)
   public void normalLongs(Blackhole blackhole) throws Exception
   {
-    for (int i = 0; i < maxRows; i++) {
+    for (int i = 0; i < MAX_ROWS; i++) {
       InputRow row = longRows.get(i);
       int rv = incIndex.add(row).getRowCount();
       blackhole.consume(rv);
@@ -169,10 +169,10 @@ public class IncrementalIndexRowTypeBenchmark
   @Benchmark
   @BenchmarkMode(Mode.AverageTime)
   @OutputTimeUnit(TimeUnit.MICROSECONDS)
-  @OperationsPerInvocation(maxRows)
+  @OperationsPerInvocation(MAX_ROWS)
   public void normalFloats(Blackhole blackhole) throws Exception
   {
-    for (int i = 0; i < maxRows; i++) {
+    for (int i = 0; i < MAX_ROWS; i++) {
       InputRow row = floatRows.get(i);
       int rv = incFloatIndex.add(row).getRowCount();
       blackhole.consume(rv);
@@ -182,10 +182,10 @@ public class IncrementalIndexRowTypeBenchmark
   @Benchmark
   @BenchmarkMode(Mode.AverageTime)
   @OutputTimeUnit(TimeUnit.MICROSECONDS)
-  @OperationsPerInvocation(maxRows)
+  @OperationsPerInvocation(MAX_ROWS)
   public void normalStrings(Blackhole blackhole) throws Exception
   {
-    for (int i = 0; i < maxRows; i++) {
+    for (int i = 0; i < MAX_ROWS; i++) {
       InputRow row = stringRows.get(i);
       int rv = incStrIndex.add(row).getRowCount();
       blackhole.consume(rv);

benchmarks/src/main/java/org/apache/druid/benchmark/LongCompressionBenchmarkFileGenerator.java

@@ -46,11 +46,11 @@ public class LongCompressionBenchmarkFileGenerator
 {
   private static final Logger log = new Logger(LongCompressionBenchmarkFileGenerator.class);
   public static final int ROW_NUM = 5000000;
-  public static final List<CompressionStrategy> compressions =
+  public static final List<CompressionStrategy> COMPRESSIONS =
       ImmutableList.of(
           CompressionStrategy.LZ4,
           CompressionStrategy.NONE);
-  public static final List<CompressionFactory.LongEncodingStrategy> encodings =
+  public static final List<CompressionFactory.LongEncodingStrategy> ENCODINGS =
       ImmutableList.of(CompressionFactory.LongEncodingStrategy.AUTO, CompressionFactory.LongEncodingStrategy.LONGS);
 
   private static String dirPath = "longCompress/";
@@ -130,8 +130,8 @@ public class LongCompressionBenchmarkFileGenerator
 
     // create compressed files using all combinations of CompressionStrategy and LongEncoding provided
     for (Map.Entry<String, BenchmarkColumnValueGenerator> entry : generators.entrySet()) {
-      for (CompressionStrategy compression : compressions) {
+      for (CompressionStrategy compression : COMPRESSIONS) {
-        for (CompressionFactory.LongEncodingStrategy encoding : encodings) {
+        for (CompressionFactory.LongEncodingStrategy encoding : ENCODINGS) {
           String name = entry.getKey() + "-" + compression + "-" + encoding;
           log.info("%s: ", name);
           File compFile = new File(dir, name);

benchmarks/src/main/java/org/apache/druid/benchmark/StupidPoolConcurrencyBenchmark.java

@@ -36,7 +36,7 @@ import java.util.concurrent.atomic.AtomicLong;
 
 public class StupidPoolConcurrencyBenchmark
 {
-  private static final Object simpleObject = new Object();
+  private static final Object SIMPLE_OBJECT = new Object();
 
   @State(Scope.Benchmark)
   public static class BenchmarkPool
@@ -50,7 +50,7 @@ public class StupidPoolConcurrencyBenchmark
           public Object get()
           {
             numPools.incrementAndGet();
-            return simpleObject;
+            return SIMPLE_OBJECT;
           }
         }
     );

benchmarks/src/main/java/org/apache/druid/benchmark/query/timecompare/TimeCompareBenchmark.java

@@ -116,12 +116,12 @@ public class TimeCompareBenchmark
   @Param({"100"})
   private int threshold;
 
-  protected static final Map<String, String> scriptDoubleSum = new HashMap<>();
+  protected static final Map<String, String> SCRIPT_DOUBLE_SUM = new HashMap<>();
 
   static {
-    scriptDoubleSum.put("fnAggregate", "function aggregate(current, a) { return current + a }");
+    SCRIPT_DOUBLE_SUM.put("fnAggregate", "function aggregate(current, a) { return current + a }");
-    scriptDoubleSum.put("fnReset", "function reset() { return 0 }");
+    SCRIPT_DOUBLE_SUM.put("fnReset", "function reset() { return 0 }");
-    scriptDoubleSum.put("fnCombine", "function combine(a,b) { return a + b }");
+    SCRIPT_DOUBLE_SUM.put("fnCombine", "function combine(a,b) { return a + b }");
   }
 
   private static final Logger log = new Logger(TimeCompareBenchmark.class);

benchmarks/src/main/java/org/apache/druid/server/coordinator/CostBalancerStrategyBenchmark.java

@@ -41,7 +41,7 @@ import java.util.concurrent.TimeUnit;
 @State(Scope.Benchmark)
 public class CostBalancerStrategyBenchmark
 {
-  private static final DateTime t0 = DateTimes.of("2016-01-01T01:00:00Z");
+  private static final DateTime T0 = DateTimes.of("2016-01-01T01:00:00Z");
 
   private List<DataSegment> segments;
   private DataSegment segment;
@@ -55,12 +55,12 @@ public class CostBalancerStrategyBenchmark
   @Setup
   public void setupDummyCluster()
   {
-    segment = createSegment(t0);
+    segment = createSegment(T0);
 
     Random r = ThreadLocalRandom.current();
     segments = new ArrayList<>(n);
     for (int i = 0; i < n; ++i) {
-      final DateTime t = t0.minusHours(r.nextInt(365 * 24) - 365 * 12);
+      final DateTime t = T0.minusHours(r.nextInt(365 * 24) - 365 * 12);
       segments.add(createSegment(t));
     }
   }

codestyle/checkstyle-suppressions.xml

@@ -48,6 +48,13 @@
   <suppress checks="Indentation" files="[\\/]target[\\/]generated-test-sources[\\/]" />
   <suppress checks="Indentation" files="ProtoTestEventWrapper.java" />
   <suppress checks="Regexp" id="argumentLineBreaking" files="ProtoTestEventWrapper.java" />
+  <suppress checks="ConstantName" files="ProtoTestEventWrapper.java" />
+  <suppress checks="ConstantName" files="MySubRecord.java" />
+  <suppress checks="ConstantName" files="SomeAvroDatum.java" />
+  <suppress checks="ConstantName" files="MyFixed.java" />
+  <suppress checks="ConstantName" files="MyEnum.java" />
+  <suppress checks="ConstantName" files="Author" />
+  <suppress checks="ConstantName" files="Book" />
 
   <suppress checks="OneStatementPerLine" files="[\\/]target[\\/]generated-test-sources[\\/]" />
 

codestyle/checkstyle.xml

@@ -319,5 +319,8 @@ codestyle/checkstyle.xml.
"/>
     <module name="LocalFinalVariableName">
       <property name="format" value="^[a-z_]*[a-z0-9][a-zA-Z0-9_]*$"/>
     </module>
+    <module name="ConstantName">
+      <property name="format" value="^log(ger)?$|^[A-Z][A-Z0-9]*(_[A-Z0-9]+)*$"/>
+    </module>
   </module>
 </module>

core/src/main/java/org/apache/druid/collections/ReferenceCountingResourceHolder.java

@@ -33,11 +33,11 @@ public class ReferenceCountingResourceHolder<T> implements ResourceHolder<T>
 {
   private static final Logger log = new Logger(ReferenceCountingResourceHolder.class);
 
-  private static final AtomicLong leakedResources = new AtomicLong();
+  private static final AtomicLong LEAKED_RESOURCES = new AtomicLong();
 
   public static long leakedResources()
   {
-    return leakedResources.get();
+    return LEAKED_RESOURCES.get();
   }
 
   private final T object;
@@ -164,7 +164,7 @@ public class ReferenceCountingResourceHolder<T> implements ResourceHolder<T>
         }
         if (refCount.compareAndSet(count, 0)) {
           try {
-            leakedResources.incrementAndGet();
+            LEAKED_RESOURCES.incrementAndGet();
             closer.close();
             return;
           }

core/src/main/java/org/apache/druid/data/input/impl/TimestampSpec.java

@@ -53,7 +53,7 @@ public class TimestampSpec
   private final Function<Object, DateTime> timestampConverter;
 
   // remember last value parsed
-  private static final ThreadLocal<ParseCtx> parseCtx = ThreadLocal.withInitial(ParseCtx::new);
+  private static final ThreadLocal<ParseCtx> PARSE_CTX = ThreadLocal.withInitial(ParseCtx::new);
 
   @JsonCreator
   public TimestampSpec(
@@ -98,7 +98,7 @@ public class TimestampSpec
   {
     DateTime extracted = missingValue;
     if (input != null) {
-      ParseCtx ctx = parseCtx.get();
+      ParseCtx ctx = PARSE_CTX.get();
       // Check if the input is equal to the last input, so we don't need to parse it again
       if (input.equals(ctx.lastTimeObject)) {
         extracted = ctx.lastDateTime;
@@ -107,7 +107,7 @@ public class TimestampSpec
         ParseCtx newCtx = new ParseCtx();
         newCtx.lastTimeObject = input;
         newCtx.lastDateTime = extracted;
-        parseCtx.set(newCtx);
+        PARSE_CTX.set(newCtx);
       }
     }
     return extracted;

core/src/main/java/org/apache/druid/jackson/CommaListJoinSerializer.java

@@ -31,7 +31,7 @@ import java.util.List;
  */
 public class CommaListJoinSerializer extends StdScalarSerializer<List<String>>
 {
-  private static final Joiner joiner = Joiner.on(",");
+  private static final Joiner JOINER = Joiner.on(",");
 
   protected CommaListJoinSerializer()
   {
@@ -41,6 +41,6 @@ public class CommaListJoinSerializer extends StdScalarSerializer<List<String>>
   @Override
   public void serialize(List<String> value, JsonGenerator jgen, SerializerProvider provider) throws IOException
   {
-    jgen.writeString(joiner.join(value));
+    jgen.writeString(JOINER.join(value));
   }
 }

core/src/main/java/org/apache/druid/java/util/common/granularity/Granularity.java

@@ -43,11 +43,11 @@ public abstract class Granularity implements Cacheable
   /**
    * Default patterns for parsing paths.
    */
-  private static final Pattern defaultPathPattern =
+  private static final Pattern DEFAULT_PATH_PATTERN =
       Pattern.compile(
           "^.*[Yy]=(\\d{4})/(?:[Mm]=(\\d{2})/(?:[Dd]=(\\d{2})/(?:[Hh]=(\\d{2})/(?:[Mm]=(\\d{2})/(?:[Ss]=(\\d{2})/)?)?)?)?)?.*$"
       );
-  private static final Pattern hivePathPattern =
+  private static final Pattern HIVE_PATH_PATTERN =
       Pattern.compile("^.*dt=(\\d{4})(?:-(\\d{2})(?:-(\\d{2})(?:-(\\d{2})(?:-(\\d{2})(?:-(\\d{2})?)?)?)?)?)?/.*$");
 
   @JsonCreator
@@ -150,13 +150,13 @@ public abstract class Granularity implements Cacheable
   // Used by the toDate implementations.
   final Integer[] getDateValues(String filePath, Formatter formatter)
   {
-    Pattern pattern = defaultPathPattern;
+    Pattern pattern = DEFAULT_PATH_PATTERN;
     switch (formatter) {
       case DEFAULT:
       case LOWER_DEFAULT:
         break;
       case HIVE:
-        pattern = hivePathPattern;
+        pattern = HIVE_PATH_PATTERN;
         break;
       default:
         throw new IAE("Format %s not supported", formatter);

core/src/main/java/org/apache/druid/java/util/common/io/smoosh/FileSmoosher.java

@@ -70,7 +70,7 @@ import java.util.TreeMap;
 public class FileSmoosher implements Closeable
 {
   private static final String FILE_EXTENSION = "smoosh";
-  private static final Joiner joiner = Joiner.on(",");
+  private static final Joiner JOINER = Joiner.on(",");
   private static final Logger LOG = new Logger(FileSmoosher.class);
 
   private final File baseDir;
@@ -376,7 +376,7 @@ public class FileSmoosher implements Closeable
       for (Map.Entry<String, Metadata> entry : internalFiles.entrySet()) {
         final Metadata metadata = entry.getValue();
         out.write(
-            joiner.join(
+            JOINER.join(
                 entry.getKey(),
                 metadata.getFileNum(),
                 metadata.getStartOffset(),

core/src/main/java/org/apache/druid/java/util/common/parsers/JSONToLowerParser.java

@@ -47,7 +47,7 @@ import java.util.Set;
 @Deprecated
 public class JSONToLowerParser implements Parser<String, Object>
 {
-  private static final Function<JsonNode, Object> valueFunction = new Function<JsonNode, Object>()
+  private static final Function<JsonNode, Object> VALUE_FUNCTION = new Function<JsonNode, Object>()
   {
     @Override
     public Object apply(JsonNode node)
@@ -128,14 +128,14 @@ public class JSONToLowerParser implements Parser<String, Object>
         if (node.isArray()) {
           final List<Object> nodeValue = Lists.newArrayListWithExpectedSize(node.size());
           for (final JsonNode subnode : node) {
-            final Object subnodeValue = valueFunction.apply(subnode);
+            final Object subnodeValue = VALUE_FUNCTION.apply(subnode);
             if (subnodeValue != null) {
               nodeValue.add(subnodeValue);
             }
           }
           map.put(StringUtils.toLowerCase(key), nodeValue); // difference from JSONParser parse()
         } else {
-          final Object nodeValue = valueFunction.apply(node);
+          final Object nodeValue = VALUE_FUNCTION.apply(node);
           if (nodeValue != null) {
             map.put(StringUtils.toLowerCase(key), nodeValue); // difference from JSONParser parse()
           }

core/src/main/java/org/apache/druid/java/util/emitter/core/HttpPostEmitter.java

@@ -90,7 +90,7 @@ public class HttpPostEmitter implements Flushable, Closeable, Emitter
   private static final byte[] LARGE_EVENTS_STOP = new byte[]{};
 
   private static final Logger log = new Logger(HttpPostEmitter.class);
-  private static final AtomicInteger instanceCounter = new AtomicInteger();
+  private static final AtomicInteger INSTANCE_COUNTER = new AtomicInteger();
 
   final BatchingStrategy batchingStrategy;
   final HttpEmitterConfig config;
@@ -484,7 +484,7 @@ public class HttpPostEmitter implements Flushable, Closeable, Emitter
 
     EmittingThread(HttpEmitterConfig config)
     {
-      super("HttpPostEmitter-" + instanceCounter.incrementAndGet());
+      super("HttpPostEmitter-" + INSTANCE_COUNTER.incrementAndGet());
       setDaemon(true);
       timeoutLessThanMinimumException = new TimeoutException(
           "Timeout less than minimum [" + config.getMinHttpTimeoutMillis() + "] ms."

core/src/main/java/org/apache/druid/java/util/http/client/Request.java

@@ -44,7 +44,7 @@ import java.util.Map;
  */
 public class Request
 {
-  private static final ChannelBufferFactory factory = HeapChannelBufferFactory.getInstance();
+  private static final ChannelBufferFactory FACTORY = HeapChannelBufferFactory.getInstance();
 
   private final HttpMethod method;
   private final URL url;
@@ -147,7 +147,7 @@ public class Request
 
   public Request setContent(String contentType, byte[] bytes, int offset, int length)
   {
-    return setContent(contentType, factory.getBuffer(bytes, offset, length));
+    return setContent(contentType, FACTORY.getBuffer(bytes, offset, length));
   }
 
   public Request setContent(String contentType, ChannelBuffer content)

core/src/main/java/org/apache/druid/java/util/metrics/SigarUtil.java

@@ -73,12 +73,12 @@ public class SigarUtil
    */
   private static class CurrentProcessIdHolder
   {
-    private static final long currentProcessId = new Sigar().getPid();
+    private static final long CURRENT_PROCESS_ID = new Sigar().getPid();
   }
 
   public static long getCurrentProcessId()
   {
-    return CurrentProcessIdHolder.currentProcessId;
+    return CurrentProcessIdHolder.CURRENT_PROCESS_ID;
   }
 
 }

core/src/main/java/org/apache/druid/timeline/partition/HashBasedNumberedShardSpec.java

@@ -38,7 +38,7 @@ import java.util.List;
 
 public class HashBasedNumberedShardSpec extends NumberedShardSpec
 {
-  private static final HashFunction hashFunction = Hashing.murmur3_32();
+  private static final HashFunction HASH_FUNCTION = Hashing.murmur3_32();
   private static final List<String> DEFAULT_PARTITION_DIMENSIONS = ImmutableList.of();
 
   private final ObjectMapper jsonMapper;
@@ -100,7 +100,7 @@ public class HashBasedNumberedShardSpec extends NumberedShardSpec
   @VisibleForTesting
   public static int hash(ObjectMapper jsonMapper, List<Object> objects) throws JsonProcessingException
   {
-    return hashFunction.hashBytes(jsonMapper.writeValueAsBytes(objects)).asInt();
+    return HASH_FUNCTION.hashBytes(jsonMapper.writeValueAsBytes(objects)).asInt();
   }
 
   @Override

core/src/test/java/org/apache/druid/collections/SerializablePairTest.java

@@ -27,14 +27,14 @@ import java.io.IOException;
 
 public class SerializablePairTest
 {
-  private static final ObjectMapper jsonMapper = new ObjectMapper();
+  private static final ObjectMapper JSON_MAPPER = new ObjectMapper();
 
   @Test
   public void testBytesSerde() throws IOException
   {
     SerializablePair pair = new SerializablePair<>(5L, 9L);
-    byte[] bytes = jsonMapper.writeValueAsBytes(pair);
+    byte[] bytes = JSON_MAPPER.writeValueAsBytes(pair);
-    SerializablePair<Number, Number> deserializedPair = jsonMapper.readValue(bytes, SerializablePair.class);
+    SerializablePair<Number, Number> deserializedPair = JSON_MAPPER.readValue(bytes, SerializablePair.class);
     Assert.assertEquals(pair.lhs, deserializedPair.lhs.longValue());
     Assert.assertEquals(pair.rhs, deserializedPair.rhs.longValue());
   }
@@ -43,8 +43,8 @@ public class SerializablePairTest
   public void testStringSerde() throws IOException
   {
     SerializablePair pair = new SerializablePair<>(5L, 9L);
-    String str = jsonMapper.writeValueAsString(pair);
+    String str = JSON_MAPPER.writeValueAsString(pair);
-    SerializablePair<Number, Number> deserializedPair = jsonMapper.readValue(str, SerializablePair.class);
+    SerializablePair<Number, Number> deserializedPair = JSON_MAPPER.readValue(str, SerializablePair.class);
     Assert.assertEquals(pair.lhs, deserializedPair.lhs.longValue());
     Assert.assertEquals(pair.rhs, deserializedPair.rhs.longValue());
   }

core/src/test/java/org/apache/druid/data/input/impl/prefetch/PrefetchableTextFilesFirehoseFactoryTest.java

@@ -64,7 +64,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 {
   private static long FILE_SIZE = -1;
 
-  private static final StringInputRowParser parser = new StringInputRowParser(
+  private static final StringInputRowParser PARSER = new StringInputRowParser(
       new CSVParseSpec(
           new TimestampSpec(
               "timestamp",
@@ -163,7 +163,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 
     final List<Row> rows = new ArrayList<>();
     final File firehoseTmpDir = createFirehoseTmpDir("testWithoutCacheAndFetch");
-    try (Firehose firehose = factory.connect(parser, firehoseTmpDir)) {
+    try (Firehose firehose = factory.connect(PARSER, firehoseTmpDir)) {
       while (firehose.hasMore()) {
         rows.add(firehose.nextRow());
       }
@@ -182,7 +182,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 
     final List<Row> rows = new ArrayList<>();
     final File firehoseTmpDir = createFirehoseTmpDir("testWithoutCacheAndFetch");
-    try (Firehose firehose = factory.connect(parser, firehoseTmpDir)) {
+    try (Firehose firehose = factory.connect(PARSER, firehoseTmpDir)) {
       while (firehose.hasMore()) {
         rows.add(firehose.nextRow());
       }
@@ -201,7 +201,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 
     final List<Row> rows = new ArrayList<>();
     final File firehoseTmpDir = createFirehoseTmpDir("testWithoutCache");
-    try (Firehose firehose = factory.connect(parser, firehoseTmpDir)) {
+    try (Firehose firehose = factory.connect(PARSER, firehoseTmpDir)) {
       while (firehose.hasMore()) {
         rows.add(firehose.nextRow());
       }
@@ -220,7 +220,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 
     final List<Row> rows = new ArrayList<>();
     final File firehoseTmpDir = createFirehoseTmpDir("testWithZeroFetchCapacity");
-    try (Firehose firehose = factory.connect(parser, firehoseTmpDir)) {
+    try (Firehose firehose = factory.connect(PARSER, firehoseTmpDir)) {
       while (firehose.hasMore()) {
         rows.add(firehose.nextRow());
       }
@@ -238,7 +238,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 
     final List<Row> rows = new ArrayList<>();
     final File firehoseTmpDir = createFirehoseTmpDir("testWithCacheAndFetch");
-    try (Firehose firehose = factory.connect(parser, firehoseTmpDir)) {
+    try (Firehose firehose = factory.connect(PARSER, firehoseTmpDir)) {
       while (firehose.hasMore()) {
         rows.add(firehose.nextRow());
       }
@@ -256,7 +256,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 
     final List<Row> rows = new ArrayList<>();
     final File firehoseTmpDir = createFirehoseTmpDir("testWithLargeCacheAndSmallFetch");
-    try (Firehose firehose = factory.connect(parser, firehoseTmpDir)) {
+    try (Firehose firehose = factory.connect(PARSER, firehoseTmpDir)) {
       while (firehose.hasMore()) {
         rows.add(firehose.nextRow());
       }
@@ -274,7 +274,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 
     final List<Row> rows = new ArrayList<>();
     final File firehoseTmpDir = createFirehoseTmpDir("testWithSmallCacheAndLargeFetch");
-    try (Firehose firehose = factory.connect(parser, firehoseTmpDir)) {
+    try (Firehose firehose = factory.connect(PARSER, firehoseTmpDir)) {
       while (firehose.hasMore()) {
         rows.add(firehose.nextRow());
       }
@@ -292,7 +292,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 
     final List<Row> rows = new ArrayList<>();
     final File firehoseTmpDir = createFirehoseTmpDir("testRetry");
-    try (Firehose firehose = factory.connect(parser, firehoseTmpDir)) {
+    try (Firehose firehose = factory.connect(PARSER, firehoseTmpDir)) {
       while (firehose.hasMore()) {
         rows.add(firehose.nextRow());
       }
@@ -312,7 +312,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
     final TestPrefetchableTextFilesFirehoseFactory factory =
         TestPrefetchableTextFilesFirehoseFactory.withOpenExceptions(TEST_DIR, 5);
 
-    try (Firehose firehose = factory.connect(parser, createFirehoseTmpDir("testMaxRetry"))) {
+    try (Firehose firehose = factory.connect(PARSER, createFirehoseTmpDir("testMaxRetry"))) {
       while (firehose.hasMore()) {
         firehose.nextRow();
       }
@@ -328,7 +328,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
     final TestPrefetchableTextFilesFirehoseFactory factory =
         TestPrefetchableTextFilesFirehoseFactory.withSleepMillis(TEST_DIR, 1000);
 
-    try (Firehose firehose = factory.connect(parser, createFirehoseTmpDir("testTimeout"))) {
+    try (Firehose firehose = factory.connect(PARSER, createFirehoseTmpDir("testTimeout"))) {
       while (firehose.hasMore()) {
         firehose.nextRow();
       }
@@ -344,7 +344,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 
     for (int i = 0; i < 5; i++) {
       final List<Row> rows = new ArrayList<>();
-      try (Firehose firehose = factory.connect(parser, firehoseTmpDir)) {
+      try (Firehose firehose = factory.connect(PARSER, firehoseTmpDir)) {
         if (i > 0) {
           Assert.assertEquals(FILE_SIZE * 2, factory.getCacheManager().getTotalCachedBytes());
         }
@@ -367,7 +367,7 @@ public class PrefetchableTextFilesFirehoseFactoryTest
 
     for (int i = 0; i < 5; i++) {
       final List<Row> rows = new ArrayList<>();
-      try (Firehose firehose = factory.connect(parser, firehoseTmpDir)) {
+      try (Firehose firehose = factory.connect(PARSER, firehoseTmpDir)) {
         if (i > 0) {
           Assert.assertEquals(FILE_SIZE * 2, factory.getCacheManager().getTotalCachedBytes());
         }

core/src/test/java/org/apache/druid/java/util/common/CompressionUtilsTest.java

@@ -62,9 +62,9 @@ import java.util.zip.ZipOutputStream;
 
 public class CompressionUtilsTest
 {
-  private static final String content;
+  private static final String CONTENT;
-  private static final byte[] expected;
+  private static final byte[] EXPECTED;
-  private static final byte[] gzBytes;
+  private static final byte[] GZ_BYTES;
 
   static {
     final StringBuilder builder = new StringBuilder();
@@ -79,19 +79,19 @@ public class CompressionUtilsTest
     catch (IOException e) {
       throw new RuntimeException(e);
     }
-    content = builder.toString();
+    CONTENT = builder.toString();
-    expected = StringUtils.toUtf8(content);
+    EXPECTED = StringUtils.toUtf8(CONTENT);
 
-    final ByteArrayOutputStream gzByteStream = new ByteArrayOutputStream(expected.length);
+    final ByteArrayOutputStream gzByteStream = new ByteArrayOutputStream(EXPECTED.length);
     try (GZIPOutputStream outputStream = new GZIPOutputStream(gzByteStream)) {
-      try (ByteArrayInputStream in = new ByteArrayInputStream(expected)) {
+      try (ByteArrayInputStream in = new ByteArrayInputStream(EXPECTED)) {
         ByteStreams.copy(in, outputStream);
       }
     }
     catch (IOException e) {
       throw new RuntimeException(e);
     }
-    gzBytes = gzByteStream.toByteArray();
+    GZ_BYTES = gzByteStream.toByteArray();
   }
 
   @Rule
@@ -101,9 +101,9 @@ public class CompressionUtilsTest
 
   public static void assertGoodDataStream(InputStream stream) throws IOException
   {
-    try (final ByteArrayOutputStream bos = new ByteArrayOutputStream(expected.length)) {
+    try (final ByteArrayOutputStream bos = new ByteArrayOutputStream(EXPECTED.length)) {
       ByteStreams.copy(stream, bos);
-      Assert.assertArrayEquals(expected, bos.toByteArray());
+      Assert.assertArrayEquals(EXPECTED, bos.toByteArray());
     }
   }
 
@@ -113,7 +113,7 @@ public class CompressionUtilsTest
     testDir = temporaryFolder.newFolder("testDir");
     testFile = new File(testDir, "test.dat");
     try (OutputStream outputStream = new FileOutputStream(testFile)) {
-      outputStream.write(StringUtils.toUtf8(content));
+      outputStream.write(StringUtils.toUtf8(CONTENT));
     }
     Assert.assertTrue(testFile.getParentFile().equals(testDir));
   }
@@ -395,35 +395,35 @@ public class CompressionUtilsTest
   {
     try (OutputStream outputStream = new FileOutputStream(testFile)) {
       Assert.assertEquals(
-          gzBytes.length,
+          GZ_BYTES.length,
           ByteStreams.copy(
-              new ZeroRemainingInputStream(new ByteArrayInputStream(gzBytes)),
+              new ZeroRemainingInputStream(new ByteArrayInputStream(GZ_BYTES)),
               outputStream
           )
       );
       Assert.assertEquals(
-          gzBytes.length,
+          GZ_BYTES.length,
           ByteStreams.copy(
-              new ZeroRemainingInputStream(new ByteArrayInputStream(gzBytes)),
+              new ZeroRemainingInputStream(new ByteArrayInputStream(GZ_BYTES)),
               outputStream
           )
       );
       Assert.assertEquals(
-          gzBytes.length,
+          GZ_BYTES.length,
           ByteStreams.copy(
-              new ZeroRemainingInputStream(new ByteArrayInputStream(gzBytes)),
+              new ZeroRemainingInputStream(new ByteArrayInputStream(GZ_BYTES)),
               outputStream
           )
       );
     }
-    Assert.assertEquals(gzBytes.length * 3, testFile.length());
+    Assert.assertEquals(GZ_BYTES.length * 3, testFile.length());
     try (InputStream inputStream = new ZeroRemainingInputStream(new FileInputStream(testFile))) {
       for (int i = 0; i < 3; ++i) {
-        final byte[] bytes = new byte[gzBytes.length];
+        final byte[] bytes = new byte[GZ_BYTES.length];
         Assert.assertEquals(bytes.length, inputStream.read(bytes));
         Assert.assertArrayEquals(
             StringUtils.format("Failed on range %d", i),
-            gzBytes,
+            GZ_BYTES,
             bytes
         );
       }
@@ -435,10 +435,10 @@ public class CompressionUtilsTest
   // http://bugs.java.com/bugdatabase/view_bug.do?bug_id=7036144
   public void testGunzipBug() throws IOException
   {
-    final ByteArrayOutputStream tripleGzByteStream = new ByteArrayOutputStream(gzBytes.length * 3);
+    final ByteArrayOutputStream tripleGzByteStream = new ByteArrayOutputStream(GZ_BYTES.length * 3);
-    tripleGzByteStream.write(gzBytes);
+    tripleGzByteStream.write(GZ_BYTES);
-    tripleGzByteStream.write(gzBytes);
+    tripleGzByteStream.write(GZ_BYTES);
-    tripleGzByteStream.write(gzBytes);
+    tripleGzByteStream.write(GZ_BYTES);
     try (final InputStream inputStream = new GZIPInputStream(
         new ZeroRemainingInputStream(
             new ByteArrayInputStream(
@@ -446,17 +446,17 @@ public class CompressionUtilsTest
             )
         )
     )) {
-      try (final ByteArrayOutputStream outputStream = new ByteArrayOutputStream(expected.length * 3)) {
+      try (final ByteArrayOutputStream outputStream = new ByteArrayOutputStream(EXPECTED.length * 3)) {
         Assert.assertEquals(
             "Read terminated too soon (bug 7036144)",
-            expected.length * 3,
+            EXPECTED.length * 3,
             ByteStreams.copy(inputStream, outputStream)
         );
         final byte[] found = outputStream.toByteArray();
-        Assert.assertEquals(expected.length * 3, found.length);
+        Assert.assertEquals(EXPECTED.length * 3, found.length);
-        Assert.assertArrayEquals(expected, Arrays.copyOfRange(found, expected.length * 0, expected.length * 1));
+        Assert.assertArrayEquals(EXPECTED, Arrays.copyOfRange(found, EXPECTED.length * 0, EXPECTED.length * 1));
-        Assert.assertArrayEquals(expected, Arrays.copyOfRange(found, expected.length * 1, expected.length * 2));
+        Assert.assertArrayEquals(EXPECTED, Arrays.copyOfRange(found, EXPECTED.length * 1, EXPECTED.length * 2));
-        Assert.assertArrayEquals(expected, Arrays.copyOfRange(found, expected.length * 2, expected.length * 3));
+        Assert.assertArrayEquals(EXPECTED, Arrays.copyOfRange(found, EXPECTED.length * 2, EXPECTED.length * 3));
       }
     }
   }
@@ -468,10 +468,10 @@ public class CompressionUtilsTest
     testFile.delete();
     Assert.assertFalse(testFile.exists());
 
-    final ByteArrayOutputStream tripleGzByteStream = new ByteArrayOutputStream(gzBytes.length * 3);
+    final ByteArrayOutputStream tripleGzByteStream = new ByteArrayOutputStream(GZ_BYTES.length * 3);
-    tripleGzByteStream.write(gzBytes);
+    tripleGzByteStream.write(GZ_BYTES);
-    tripleGzByteStream.write(gzBytes);
+    tripleGzByteStream.write(GZ_BYTES);
-    tripleGzByteStream.write(gzBytes);
+    tripleGzByteStream.write(GZ_BYTES);
 
     final ByteSource inputStreamFactory = new ByteSource()
     {
@@ -482,20 +482,20 @@ public class CompressionUtilsTest
       }
     };
 
-    Assert.assertEquals((long) (expected.length * 3), CompressionUtils.gunzip(inputStreamFactory, testFile).size());
+    Assert.assertEquals((long) (EXPECTED.length * 3), CompressionUtils.gunzip(inputStreamFactory, testFile).size());
 
     try (final InputStream inputStream = new FileInputStream(testFile)) {
-      try (final ByteArrayOutputStream outputStream = new ByteArrayOutputStream(expected.length * 3)) {
+      try (final ByteArrayOutputStream outputStream = new ByteArrayOutputStream(EXPECTED.length * 3)) {
         Assert.assertEquals(
             "Read terminated too soon (7036144)",
-            expected.length * 3,
+            EXPECTED.length * 3,
             ByteStreams.copy(inputStream, outputStream)
         );
         final byte[] found = outputStream.toByteArray();
-        Assert.assertEquals(expected.length * 3, found.length);
+        Assert.assertEquals(EXPECTED.length * 3, found.length);
-        Assert.assertArrayEquals(expected, Arrays.copyOfRange(found, expected.length * 0, expected.length * 1));
+        Assert.assertArrayEquals(EXPECTED, Arrays.copyOfRange(found, EXPECTED.length * 0, EXPECTED.length * 1));
-        Assert.assertArrayEquals(expected, Arrays.copyOfRange(found, expected.length * 1, expected.length * 2));
+        Assert.assertArrayEquals(EXPECTED, Arrays.copyOfRange(found, EXPECTED.length * 1, EXPECTED.length * 2));
-        Assert.assertArrayEquals(expected, Arrays.copyOfRange(found, expected.length * 2, expected.length * 3));
+        Assert.assertArrayEquals(EXPECTED, Arrays.copyOfRange(found, EXPECTED.length * 2, EXPECTED.length * 3));
       }
     }
   }
@@ -505,14 +505,14 @@ public class CompressionUtilsTest
   public void testGunzipBugStreamWorkarround() throws IOException
   {
 
-    final ByteArrayOutputStream tripleGzByteStream = new ByteArrayOutputStream(gzBytes.length * 3);
+    final ByteArrayOutputStream tripleGzByteStream = new ByteArrayOutputStream(GZ_BYTES.length * 3);
-    tripleGzByteStream.write(gzBytes);
+    tripleGzByteStream.write(GZ_BYTES);
-    tripleGzByteStream.write(gzBytes);
+    tripleGzByteStream.write(GZ_BYTES);
-    tripleGzByteStream.write(gzBytes);
+    tripleGzByteStream.write(GZ_BYTES);
 
-    try (ByteArrayOutputStream bos = new ByteArrayOutputStream(expected.length * 3)) {
+    try (ByteArrayOutputStream bos = new ByteArrayOutputStream(EXPECTED.length * 3)) {
       Assert.assertEquals(
-          expected.length * 3,
+          EXPECTED.length * 3,
           CompressionUtils.gunzip(
               new ZeroRemainingInputStream(
                   new ByteArrayInputStream(tripleGzByteStream.toByteArray())
@@ -520,10 +520,10 @@ public class CompressionUtilsTest
           )
       );
       final byte[] found = bos.toByteArray();
-      Assert.assertEquals(expected.length * 3, found.length);
+      Assert.assertEquals(EXPECTED.length * 3, found.length);
-      Assert.assertArrayEquals(expected, Arrays.copyOfRange(found, expected.length * 0, expected.length * 1));
+      Assert.assertArrayEquals(EXPECTED, Arrays.copyOfRange(found, EXPECTED.length * 0, EXPECTED.length * 1));
-      Assert.assertArrayEquals(expected, Arrays.copyOfRange(found, expected.length * 1, expected.length * 2));
+      Assert.assertArrayEquals(EXPECTED, Arrays.copyOfRange(found, EXPECTED.length * 1, EXPECTED.length * 2));
-      Assert.assertArrayEquals(expected, Arrays.copyOfRange(found, expected.length * 2, expected.length * 3));
+      Assert.assertArrayEquals(EXPECTED, Arrays.copyOfRange(found, EXPECTED.length * 2, EXPECTED.length * 3));
     }
   }
 
@@ -704,7 +704,7 @@ public class CompressionUtilsTest
     @Override
     public int read(byte b[]) throws IOException
     {
-      final int len = Math.min(b.length, gzBytes.length - pos.get() % gzBytes.length);
+      final int len = Math.min(b.length, GZ_BYTES.length - pos.get() % GZ_BYTES.length);
       pos.addAndGet(len);
       return read(b, 0, len);
     }
@@ -719,7 +719,7 @@ public class CompressionUtilsTest
     @Override
     public int read(byte b[], int off, int len) throws IOException
     {
-      final int l = Math.min(len, gzBytes.length - pos.get() % gzBytes.length);
+      final int l = Math.min(len, GZ_BYTES.length - pos.get() % GZ_BYTES.length);
       pos.addAndGet(l);
       return super.read(b, off, l);
     }

core/src/test/java/org/apache/druid/java/util/common/RetryUtilsTest.java

@@ -28,7 +28,7 @@ import java.util.concurrent.atomic.AtomicInteger;
 
 public class RetryUtilsTest
 {
-  private static final Predicate<Throwable> isTransient = new Predicate<Throwable>()
+  private static final Predicate<Throwable> IS_TRANSIENT = new Predicate<Throwable>()
   {
     @Override
     public boolean apply(Throwable e)
@@ -46,7 +46,7 @@ public class RetryUtilsTest
           count.incrementAndGet();
           return "hey";
         },
-        isTransient,
+        IS_TRANSIENT,
         2
     );
     Assert.assertEquals("result", "hey", result);
@@ -64,7 +64,7 @@ public class RetryUtilsTest
             count.incrementAndGet();
             throw new IOException("what");
           },
-          isTransient,
+          IS_TRANSIENT,
           2
       );
     }
@@ -87,7 +87,7 @@ public class RetryUtilsTest
             throw new IOException("what");
           }
         },
-        isTransient,
+        IS_TRANSIENT,
         3
     );
     Assert.assertEquals("result", "hey", result);
@@ -108,7 +108,7 @@ public class RetryUtilsTest
               throw new IOException("uhh");
             }
           },
-          isTransient,
+          IS_TRANSIENT,
           3
       );
     }

core/src/test/java/org/apache/druid/java/util/common/lifecycle/LifecycleTest.java

@@ -42,7 +42,7 @@ import java.util.concurrent.atomic.AtomicLong;
  */
 public class LifecycleTest
 {
-  private static final Lifecycle.Handler dummyHandler = new Lifecycle.Handler()
+  private static final Lifecycle.Handler DUMMY_HANDLER = new Lifecycle.Handler()
   {
     @Override
     public void start()
@@ -319,7 +319,7 @@ public class LifecycleTest
     reachedStop.await();
 
     try {
-      lifecycle.addHandler(dummyHandler);
+      lifecycle.addHandler(DUMMY_HANDLER);
       Assert.fail("Expected exception");
     }
     catch (IllegalStateException e) {
@@ -327,7 +327,7 @@ public class LifecycleTest
     }
 
     try {
-      lifecycle.addMaybeStartHandler(dummyHandler);
+      lifecycle.addMaybeStartHandler(DUMMY_HANDLER);
       Assert.fail("Expected exception");
     }
     catch (IllegalStateException e) {

core/src/test/java/org/apache/druid/java/util/common/parsers/FlatTextFormatParserTest.java

@@ -49,7 +49,7 @@ public class FlatTextFormatParserTest
     );
   }
 
-  private static final FlatTextFormatParserFactory parserFactory = new FlatTextFormatParserFactory();
+  private static final FlatTextFormatParserFactory PARSER_FACTORY = new FlatTextFormatParserFactory();
 
   @Rule
   public ExpectedException expectedException = ExpectedException.none();
@@ -65,7 +65,7 @@ public class FlatTextFormatParserTest
   public void testValidHeader()
   {
     final String header = concat(format, "time", "value1", "value2");
-    final Parser<String, Object> parser = parserFactory.get(format, header);
+    final Parser<String, Object> parser = PARSER_FACTORY.get(format, header);
     Assert.assertEquals(ImmutableList.of("time", "value1", "value2"), parser.getFieldNames());
   }
 
@@ -77,14 +77,14 @@ public class FlatTextFormatParserTest
     expectedException.expect(ParseException.class);
     expectedException.expectMessage(StringUtils.format("Unable to parse header [%s]", header));
 
-    parserFactory.get(format, header);
+    PARSER_FACTORY.get(format, header);
   }
 
   @Test
   public void testWithHeader()
   {
     final String header = concat(format, "time", "value1", "value2");
-    final Parser<String, Object> parser = parserFactory.get(format, header);
+    final Parser<String, Object> parser = PARSER_FACTORY.get(format, header);
     final String body = concat(format, "hello", "world", "foo");
     final Map<String, Object> jsonMap = parser.parseToMap(body);
     Assert.assertEquals(
@@ -97,7 +97,7 @@ public class FlatTextFormatParserTest
   @Test
   public void testWithoutHeader()
   {
-    final Parser<String, Object> parser = parserFactory.get(format);
+    final Parser<String, Object> parser = PARSER_FACTORY.get(format);
     final String body = concat(format, "hello", "world", "foo");
     final Map<String, Object> jsonMap = parser.parseToMap(body);
     Assert.assertEquals(
@@ -111,7 +111,7 @@ public class FlatTextFormatParserTest
   public void testWithSkipHeaderRows()
   {
     final int skipHeaderRows = 2;
-    final Parser<String, Object> parser = parserFactory.get(format, false, skipHeaderRows);
+    final Parser<String, Object> parser = PARSER_FACTORY.get(format, false, skipHeaderRows);
     parser.startFileFromBeginning();
     final String[] body = new String[]{
         concat(format, "header", "line", "1"),
@@ -133,7 +133,7 @@ public class FlatTextFormatParserTest
   @Test
   public void testWithHeaderRow()
   {
-    final Parser<String, Object> parser = parserFactory.get(format, true, 0);
+    final Parser<String, Object> parser = PARSER_FACTORY.get(format, true, 0);
     parser.startFileFromBeginning();
     final String[] body = new String[]{
         concat(format, "time", "value1", "value2"),
@@ -151,7 +151,7 @@ public class FlatTextFormatParserTest
   @Test
   public void testWithHeaderRowOfEmptyColumns()
   {
-    final Parser<String, Object> parser = parserFactory.get(format, true, 0);
+    final Parser<String, Object> parser = PARSER_FACTORY.get(format, true, 0);
     parser.startFileFromBeginning();
     final String[] body = new String[]{
         concat(format, "time", "", "value2", ""),
@@ -169,7 +169,7 @@ public class FlatTextFormatParserTest
   @Test
   public void testWithDifferentHeaderRows()
   {
-    final Parser<String, Object> parser = parserFactory.get(format, true, 0);
+    final Parser<String, Object> parser = PARSER_FACTORY.get(format, true, 0);
     parser.startFileFromBeginning();
     final String[] body = new String[]{
         concat(format, "time", "value1", "value2"),
@@ -206,7 +206,7 @@ public class FlatTextFormatParserTest
     );
 
     final int skipHeaderRows = 2;
-    final Parser<String, Object> parser = parserFactory.get(format, false, skipHeaderRows);
+    final Parser<String, Object> parser = PARSER_FACTORY.get(format, false, skipHeaderRows);
     final String[] body = new String[]{
         concat(format, "header", "line", "1"),
         concat(format, "header", "line", "2"),

core/src/test/java/org/apache/druid/java/util/common/parsers/JSONPathParserTest.java

@@ -32,13 +32,13 @@ import java.util.Map;
 
 public class JSONPathParserTest
 {
-  private static final String json =
+  private static final String JSON =
       "{\"one\": \"foo\", \"two\" : [\"bar\", \"baz\"], \"three\" : \"qux\", \"four\" : null}";
-  private static final String numbersJson =
+  private static final String NUMBERS_JSON =
       "{\"five\" : 5.0, \"six\" : 6, \"many\" : 1234567878900, \"toomany\" : 1234567890000000000000}";
-  private static final String whackyCharacterJson =
+  private static final String WHACKY_CHARACTER_JSON =
       "{\"one\": \"foo\\uD900\"}";
-  private static final String nestedJson =
+  private static final String NESTED_JSON =
       "{\"simpleVal\":\"text\", \"ignore_me\":[1, {\"x\":2}], \"blah\":[4,5,6], \"newmet\":5, " +
       "\"foo\":{\"bar1\":\"aaa\", \"bar2\":\"bbb\"}, " +
       "\"baz\":[1,2,3], \"timestamp\":\"2999\", \"foo.bar1\":\"Hello world!\", " +
@@ -47,7 +47,7 @@ public class JSONPathParserTest
       "\"testMapConvert\":{\"big\": 1234567890000000000000, \"big2\":{\"big2\":1234567890000000000000}}, " +
       "\"testEmptyList\": [], " +
       "\"hey\":[{\"barx\":\"asdf\"}], \"met\":{\"a\":[7,8,9]}}";
-  private static final String notJson = "***@#%R#*(TG@(*H(#@(#@((H#(@TH@(#TH(@SDHGKJDSKJFBSBJK";
+  private static final String NOT_JSON = "***@#%R#*(TG@(*H(#@(#@((H#(@TH@(#TH(@SDHGKJDSKJFBSBJK";
 
   @Rule
   public ExpectedException thrown = ExpectedException.none();
@@ -57,7 +57,7 @@ public class JSONPathParserTest
   {
     List<JSONPathFieldSpec> fields = new ArrayList<>();
     final Parser<String, Object> jsonParser = new JSONPathParser(new JSONPathSpec(true, fields), null);
-    final Map<String, Object> jsonMap = jsonParser.parseToMap(json);
+    final Map<String, Object> jsonMap = jsonParser.parseToMap(JSON);
     Assert.assertEquals(
         "jsonMap",
         ImmutableMap.of("one", "foo", "two", ImmutableList.of("bar", "baz"), "three", "qux"),
@@ -70,7 +70,7 @@ public class JSONPathParserTest
   {
     List<JSONPathFieldSpec> fields = new ArrayList<>();
     final Parser<String, Object> jsonParser = new JSONPathParser(new JSONPathSpec(true, fields), null);
-    final Map<String, Object> jsonMap = jsonParser.parseToMap(numbersJson);
+    final Map<String, Object> jsonMap = jsonParser.parseToMap(NUMBERS_JSON);
     Assert.assertEquals(
         "jsonMap",
         ImmutableMap.of("five", 5.0, "six", 6L, "many", 1234567878900L, "toomany", 1.23456789E21),
@@ -83,7 +83,7 @@ public class JSONPathParserTest
   {
     List<JSONPathFieldSpec> fields = new ArrayList<>();
     final Parser<String, Object> jsonParser = new JSONPathParser(new JSONPathSpec(true, fields), null);
-    final Map<String, Object> jsonMap = jsonParser.parseToMap(whackyCharacterJson);
+    final Map<String, Object> jsonMap = jsonParser.parseToMap(WHACKY_CHARACTER_JSON);
     Assert.assertEquals(
         "jsonMap",
         ImmutableMap.of("one", "foo?"),
@@ -113,7 +113,7 @@ public class JSONPathParserTest
 
 
     final Parser<String, Object> jsonParser = new JSONPathParser(new JSONPathSpec(true, fields), null);
-    final Map<String, Object> jsonMap = jsonParser.parseToMap(nestedJson);
+    final Map<String, Object> jsonMap = jsonParser.parseToMap(NESTED_JSON);
 
     // Root fields
     Assert.assertEquals(ImmutableList.of(1L, 2L, 3L), jsonMap.get("baz"));
@@ -174,7 +174,7 @@ public class JSONPathParserTest
     fields.add(new JSONPathFieldSpec(JSONPathFieldType.JQ, "jq-met-array", ".met.a"));
 
     final Parser<String, Object> jsonParser = new JSONPathParser(new JSONPathSpec(false, fields), null);
-    final Map<String, Object> jsonMap = jsonParser.parseToMap(nestedJson);
+    final Map<String, Object> jsonMap = jsonParser.parseToMap(NESTED_JSON);
 
     // Root fields
     Assert.assertEquals("text", jsonMap.get("simpleVal"));
@@ -211,7 +211,7 @@ public class JSONPathParserTest
     thrown.expectMessage("Cannot have duplicate field definition: met-array");
 
     final Parser<String, Object> jsonParser = new JSONPathParser(new JSONPathSpec(false, fields), null);
-    jsonParser.parseToMap(nestedJson);
+    jsonParser.parseToMap(NESTED_JSON);
   }
 
   @Test
@@ -225,7 +225,7 @@ public class JSONPathParserTest
     thrown.expectMessage("Cannot have duplicate field definition: met-array");
 
     final Parser<String, Object> jsonParser = new JSONPathParser(new JSONPathSpec(false, fields), null);
-    jsonParser.parseToMap(nestedJson);
+    jsonParser.parseToMap(NESTED_JSON);
   }
 
   @Test
@@ -234,9 +234,9 @@ public class JSONPathParserTest
     List<JSONPathFieldSpec> fields = new ArrayList<>();
 
     thrown.expect(ParseException.class);
-    thrown.expectMessage("Unable to parse row [" + notJson + "]");
+    thrown.expectMessage("Unable to parse row [" + NOT_JSON + "]");
 
     final Parser<String, Object> jsonParser = new JSONPathParser(new JSONPathSpec(true, fields), null);
-    jsonParser.parseToMap(notJson);
+    jsonParser.parseToMap(NOT_JSON);
   }
 }

core/src/test/java/org/apache/druid/java/util/emitter/core/EmitterTest.java

@@ -57,7 +57,7 @@ import java.util.stream.Stream;
  */
 public class EmitterTest
 {
-  private static final ObjectMapper jsonMapper = new ObjectMapper();
+  private static final ObjectMapper JSON_MAPPER = new ObjectMapper();
   public static String TARGET_URL = "http://metrics.foo.bar/";
   public static final Response OK_RESPONSE = Stream
       .of(responseBuilder(HttpVersion.HTTP_1_1, HttpResponseStatus.CREATED))
@@ -120,7 +120,7 @@ public class EmitterTest
     HttpPostEmitter emitter = new HttpPostEmitter(
         config,
         httpClient,
-        jsonMapper
+        JSON_MAPPER
     );
     emitter.start();
     return emitter;
@@ -135,7 +135,7 @@ public class EmitterTest
     HttpPostEmitter emitter = new HttpPostEmitter(
         config,
         httpClient,
-        jsonMapper
+        JSON_MAPPER
     );
     emitter.start();
     return emitter;
@@ -150,7 +150,7 @@ public class EmitterTest
     props.setProperty("org.apache.druid.java.util.emitter.flushCount", String.valueOf(size));
 
     Lifecycle lifecycle = new Lifecycle();
-    Emitter emitter = Emitters.create(props, httpClient, jsonMapper, lifecycle);
+    Emitter emitter = Emitters.create(props, httpClient, JSON_MAPPER, lifecycle);
     Assert.assertTrue(StringUtils.format(
         "HttpPostEmitter emitter should be created, but found %s",
         emitter.getClass().getName()
@@ -169,7 +169,7 @@ public class EmitterTest
     HttpPostEmitter emitter = new HttpPostEmitter(
         config,
         httpClient,
-        jsonMapper
+        JSON_MAPPER
     );
     emitter.start();
     return emitter;
@@ -187,7 +187,7 @@ public class EmitterTest
     HttpPostEmitter emitter = new HttpPostEmitter(
         config,
         httpClient,
-        jsonMapper
+        JSON_MAPPER
     );
     emitter.start();
     return emitter;
@@ -203,7 +203,7 @@ public class EmitterTest
     HttpPostEmitter emitter = new HttpPostEmitter(
         config,
         httpClient,
-        jsonMapper
+        JSON_MAPPER
     );
     emitter.start();
     return emitter;
@@ -232,8 +232,8 @@ public class EmitterTest
             Assert.assertEquals(
                 StringUtils.format(
                     "[%s,%s]\n",
-                    jsonMapper.writeValueAsString(events.get(0)),
+                    JSON_MAPPER.writeValueAsString(events.get(0)),
-                    jsonMapper.writeValueAsString(events.get(1))
+                    JSON_MAPPER.writeValueAsString(events.get(1))
                 ),
                 StandardCharsets.UTF_8.decode(request.getByteBufferData().slice()).toString()
             );
@@ -274,8 +274,8 @@ public class EmitterTest
             Assert.assertEquals(
                 StringUtils.format(
                     "[%s,%s]\n",
-                    jsonMapper.writeValueAsString(events.get(0)),
+                    JSON_MAPPER.writeValueAsString(events.get(0)),
-                    jsonMapper.writeValueAsString(events.get(1))
+                    JSON_MAPPER.writeValueAsString(events.get(1))
                 ),
                 StandardCharsets.UTF_8.decode(request.getByteBufferData().slice()).toString()
             );
@@ -459,8 +459,8 @@ public class EmitterTest
             Assert.assertEquals(
                 StringUtils.format(
                     "%s\n%s\n",
-                    jsonMapper.writeValueAsString(events.get(0)),
+                    JSON_MAPPER.writeValueAsString(events.get(0)),
-                    jsonMapper.writeValueAsString(events.get(1))
+                    JSON_MAPPER.writeValueAsString(events.get(1))
                 ),
                 StandardCharsets.UTF_8.decode(request.getByteBufferData().slice()).toString()
             );
@@ -513,8 +513,8 @@ public class EmitterTest
             Assert.assertEquals(
                 StringUtils.format(
                     "[%s,%s]\n",
-                    jsonMapper.writeValueAsString(events.get(counter.getAndIncrement())),
+                    JSON_MAPPER.writeValueAsString(events.get(counter.getAndIncrement())),
-                    jsonMapper.writeValueAsString(events.get(counter.getAndIncrement()))
+                    JSON_MAPPER.writeValueAsString(events.get(counter.getAndIncrement()))
                 ),
                 StandardCharsets.UTF_8.decode(request.getByteBufferData().slice()).toString()
             );
@@ -576,8 +576,8 @@ public class EmitterTest
             Assert.assertEquals(
                 StringUtils.format(
                     "[%s,%s]\n",
-                    jsonMapper.writeValueAsString(events.get(0)),
+                    JSON_MAPPER.writeValueAsString(events.get(0)),
-                    jsonMapper.writeValueAsString(events.get(1))
+                    JSON_MAPPER.writeValueAsString(events.get(1))
                 ),
                 baos.toString(StandardCharsets.UTF_8.name())
             );

core/src/test/java/org/apache/druid/java/util/emitter/core/HttpEmitterTest.java

@@ -35,7 +35,7 @@ import java.util.concurrent.atomic.AtomicLong;
 public class HttpEmitterTest
 {
   private final MockHttpClient httpClient = new MockHttpClient();
-  private static final ObjectMapper objectMapper = new ObjectMapper()
+  private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper()
   {
     @Override
     public byte[] writeValueAsBytes(Object value)
@@ -71,7 +71,7 @@ public class HttpEmitterTest
         .setBatchingStrategy(BatchingStrategy.ONLY_EVENTS)
         .setHttpTimeoutAllowanceFactor(timeoutAllowanceFactor)
         .build();
-    final HttpPostEmitter emitter = new HttpPostEmitter(config, httpClient, objectMapper);
+    final HttpPostEmitter emitter = new HttpPostEmitter(config, httpClient, OBJECT_MAPPER);
 
     long startMs = System.currentTimeMillis();
     emitter.start();

core/src/test/java/org/apache/druid/java/util/emitter/core/HttpPostEmitterStressTest.java

@@ -42,7 +42,7 @@ import java.util.concurrent.ThreadLocalRandom;
 public class HttpPostEmitterStressTest
 {
   private static final int N = 10_000;
-  private static final ObjectMapper objectMapper = new ObjectMapper()
+  private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper()
   {
     @Override
     public byte[] writeValueAsBytes(Object value)
@@ -64,7 +64,7 @@ public class HttpPostEmitterStressTest
         // For this test, we don't need any batches to be dropped, i. e. "gaps" in data
         .setBatchQueueSizeLimit(1000)
         .build();
-    final HttpPostEmitter emitter = new HttpPostEmitter(config, httpClient, objectMapper);
+    final HttpPostEmitter emitter = new HttpPostEmitter(config, httpClient, OBJECT_MAPPER);
     int nThreads = Runtime.getRuntime().availableProcessors() * 2;
     final List<IntList> eventsPerThread = new ArrayList<>(nThreads);
     final List<List<Batch>> eventBatchesPerThread = new ArrayList<>(nThreads);

core/src/test/java/org/apache/druid/java/util/emitter/core/HttpPostEmitterTest.java

@@ -35,7 +35,7 @@ import java.util.concurrent.atomic.AtomicReference;
 public class HttpPostEmitterTest
 {
 
-  private static final ObjectMapper objectMapper = new ObjectMapper()
+  private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper()
   {
     @Override
     public byte[] writeValueAsBytes(Object value)
@@ -72,7 +72,7 @@ public class HttpPostEmitterTest
         .setMaxBatchSize(1024 * 1024)
         .setBatchQueueSizeLimit(1000)
         .build();
-    final HttpPostEmitter emitter = new HttpPostEmitter(config, httpClient, objectMapper);
+    final HttpPostEmitter emitter = new HttpPostEmitter(config, httpClient, OBJECT_MAPPER);
     emitter.start();
 
     // emit first event

core/src/test/java/org/apache/druid/java/util/emitter/core/ParametrizedUriEmitterTest.java

@@ -42,7 +42,7 @@ import java.util.Properties;
 
 public class ParametrizedUriEmitterTest
 {
-  private static final ObjectMapper jsonMapper = new ObjectMapper();
+  private static final ObjectMapper JSON_MAPPER = new ObjectMapper();
 
   private MockHttpClient httpClient;
   private Lifecycle lifecycle;
@@ -98,8 +98,8 @@ public class ParametrizedUriEmitterTest
             Assert.assertEquals(
                 StringUtils.format(
                     "[%s,%s]\n",
-                    jsonMapper.writeValueAsString(events.get(0)),
+                    JSON_MAPPER.writeValueAsString(events.get(0)),
-                    jsonMapper.writeValueAsString(events.get(1))
+                    JSON_MAPPER.writeValueAsString(events.get(1))
                 ),
                 StandardCharsets.UTF_8.decode(request.getByteBufferData().slice()).toString()
             );
@@ -148,8 +148,8 @@ public class ParametrizedUriEmitterTest
     emitter.flush();
     Assert.assertTrue(httpClient.succeeded());
     Map<String, String> expected = ImmutableMap.of(
-        "http://example.com/test1", StringUtils.format("[%s]\n", jsonMapper.writeValueAsString(events.get(0))),
+        "http://example.com/test1", StringUtils.format("[%s]\n", JSON_MAPPER.writeValueAsString(events.get(0))),
-        "http://example.com/test2", StringUtils.format("[%s]\n", jsonMapper.writeValueAsString(events.get(1)))
+        "http://example.com/test2", StringUtils.format("[%s]\n", JSON_MAPPER.writeValueAsString(events.get(1)))
     );
     Assert.assertEquals(expected, results);
   }
@@ -173,8 +173,8 @@ public class ParametrizedUriEmitterTest
             Assert.assertEquals(
                 StringUtils.format(
                     "[%s,%s]\n",
-                    jsonMapper.writeValueAsString(events.get(0)),
+                    JSON_MAPPER.writeValueAsString(events.get(0)),
-                    jsonMapper.writeValueAsString(events.get(1))
+                    JSON_MAPPER.writeValueAsString(events.get(1))
                 ),
                 StandardCharsets.UTF_8.decode(request.getByteBufferData().slice()).toString()
             );

core/src/test/java/org/apache/druid/metadata/DefaultPasswordProviderTest.java

@@ -25,46 +25,46 @@ import org.junit.Test;
 
 public class DefaultPasswordProviderTest
 {
-  private static final String pwd = "nothing";
+  private static final String PWD = "nothing";
-  private static final ObjectMapper jsonMapper = new ObjectMapper();
+  private static final ObjectMapper JSON_MAPPER = new ObjectMapper();
 
   @Test
   public void testExplicitConstruction()
   {
-    DefaultPasswordProvider pp = new DefaultPasswordProvider(pwd);
+    DefaultPasswordProvider pp = new DefaultPasswordProvider(PWD);
-    Assert.assertEquals(pwd, pp.getPassword());
+    Assert.assertEquals(PWD, pp.getPassword());
   }
   
   @Test
   public void testFromStringConstruction()
   {
-    DefaultPasswordProvider pp = DefaultPasswordProvider.fromString(pwd);
+    DefaultPasswordProvider pp = DefaultPasswordProvider.fromString(PWD);
-    Assert.assertEquals(pwd, pp.getPassword());
+    Assert.assertEquals(PWD, pp.getPassword());
   }
 
   @Test
   public void testDeserializationFromJsonString() throws Exception
   {
-    PasswordProvider pp = jsonMapper.readValue("\"" + pwd + "\"",
+    PasswordProvider pp = JSON_MAPPER.readValue("\"" + PWD + "\"",
         PasswordProvider.class);
-    Assert.assertEquals(pwd, pp.getPassword());
+    Assert.assertEquals(PWD, pp.getPassword());
   }
 
   @Test
   public void testDeserializationFromJson() throws Exception
   {
-    PasswordProvider pp = jsonMapper.readValue(
+    PasswordProvider pp = JSON_MAPPER.readValue(
-        "{\"type\": \"default\", \"password\": \"" + pwd + "\"}",
+        "{\"type\": \"default\", \"password\": \"" + PWD + "\"}",
         PasswordProvider.class);
-    Assert.assertEquals(pwd, pp.getPassword());
+    Assert.assertEquals(PWD, pp.getPassword());
   }
 
   @Test
   public void testSerializationWithMixIn() throws Exception
   {
-    DefaultPasswordProvider pp = new DefaultPasswordProvider(pwd);
+    DefaultPasswordProvider pp = new DefaultPasswordProvider(PWD);
-    jsonMapper.addMixIn(PasswordProvider.class, PasswordProviderRedactionMixIn.class);
+    JSON_MAPPER.addMixIn(PasswordProvider.class, PasswordProviderRedactionMixIn.class);
-    String valueAsString = jsonMapper.writeValueAsString(pp);
+    String valueAsString = JSON_MAPPER.writeValueAsString(pp);
     Assert.assertEquals("{\"type\":\"default\"}", valueAsString);
   }
 }

core/src/test/java/org/apache/druid/metadata/EnvironmentVariablePasswordProviderTest.java

@@ -27,16 +27,16 @@ import java.io.IOException;
 
 public class EnvironmentVariablePasswordProviderTest
 {
-  private static final ObjectMapper jsonMapper = new ObjectMapper();
+  private static final ObjectMapper JSON_MAPPER = new ObjectMapper();
 
   @Test
   public void testSerde() throws IOException
   {
     String providerString = "{\"type\": \"environment\", \"variable\" : \"test\"}";
-    PasswordProvider provider = jsonMapper.readValue(providerString, PasswordProvider.class);
+    PasswordProvider provider = JSON_MAPPER.readValue(providerString, PasswordProvider.class);
     Assert.assertTrue(provider instanceof EnvironmentVariablePasswordProvider);
     Assert.assertEquals("test", ((EnvironmentVariablePasswordProvider) provider).getVariable());
-    PasswordProvider serde = jsonMapper.readValue(jsonMapper.writeValueAsString(provider), PasswordProvider.class);
+    PasswordProvider serde = JSON_MAPPER.readValue(JSON_MAPPER.writeValueAsString(provider), PasswordProvider.class);
     Assert.assertEquals(provider, serde);
   }
 }

core/src/test/java/org/apache/druid/metadata/MetadataStorageConnectorConfigTest.java

@@ -39,7 +39,7 @@ public class MetadataStorageConnectorConfigTest
   )
       throws IOException
   {
-    return jsonMapper.readValue(
+    return JSON_MAPPER.readValue(
         "{" +
         "\"createTables\": \"" + createTables + "\"," +
         "\"host\": \"" + host + "\"," +
@@ -79,7 +79,7 @@ public class MetadataStorageConnectorConfigTest
     Assert.assertTrue(metadataStorageConnectorConfig.hashCode() == metadataStorageConnectorConfig2.hashCode());
   }
 
-  private static final ObjectMapper jsonMapper = new ObjectMapper();
+  private static final ObjectMapper JSON_MAPPER = new ObjectMapper();
 
   @Test
   public void testMetadataStorageConnectionConfigSimplePassword() throws Exception
@@ -119,7 +119,7 @@ public class MetadataStorageConnectorConfigTest
       String pwd
   ) throws Exception
   {
-    MetadataStorageConnectorConfig config = jsonMapper.readValue(
+    MetadataStorageConnectorConfig config = JSON_MAPPER.readValue(
         "{" +
         "\"createTables\": \"" + createTables + "\"," +
         "\"host\": \"" + host + "\"," +
@@ -162,7 +162,7 @@ public class MetadataStorageConnectorConfigTest
           String pwd
   ) throws Exception
   {
-    MetadataStorageConnectorConfig config = jsonMapper.readValue(
+    MetadataStorageConnectorConfig config = JSON_MAPPER.readValue(
             "{" +
                     "\"createTables\": \"" + createTables + "\"," +
                     "\"host\": \"" + host + "\"," +

core/src/test/java/org/apache/druid/timeline/DataSegmentTest.java

@@ -51,7 +51,7 @@ import java.util.TreeSet;
  */
 public class DataSegmentTest
 {
-  private static final ObjectMapper mapper = new TestObjectMapper();
+  private static final ObjectMapper MAPPER = new TestObjectMapper();
   private static final int TEST_VERSION = 0x9;
 
   private static ShardSpec getShardSpec(final int partitionNum)
@@ -107,7 +107,7 @@ public class DataSegmentTest
   {
     InjectableValues.Std injectableValues = new InjectableValues.Std();
     injectableValues.addValue(DataSegment.PruneLoadSpecHolder.class, DataSegment.PruneLoadSpecHolder.DEFAULT);
-    mapper.setInjectableValues(injectableValues);
+    MAPPER.setInjectableValues(injectableValues);
   }
 
   @Test
@@ -129,8 +129,8 @@ public class DataSegmentTest
         1
     );
 
-    final Map<String, Object> objectMap = mapper.readValue(
+    final Map<String, Object> objectMap = MAPPER.readValue(
-        mapper.writeValueAsString(segment),
+        MAPPER.writeValueAsString(segment),
         JacksonUtils.TYPE_REFERENCE_MAP_STRING_OBJECT
     );
 
@@ -145,7 +145,7 @@ public class DataSegmentTest
     Assert.assertEquals(TEST_VERSION, objectMap.get("binaryVersion"));
     Assert.assertEquals(1, objectMap.get("size"));
 
-    DataSegment deserializedSegment = mapper.readValue(mapper.writeValueAsString(segment), DataSegment.class);
+    DataSegment deserializedSegment = MAPPER.readValue(MAPPER.writeValueAsString(segment), DataSegment.class);
 
     Assert.assertEquals(segment.getDataSource(), deserializedSegment.getDataSource());
     Assert.assertEquals(segment.getInterval(), deserializedSegment.getInterval());
@@ -157,13 +157,13 @@ public class DataSegmentTest
     Assert.assertEquals(segment.getSize(), deserializedSegment.getSize());
     Assert.assertEquals(segment.getId(), deserializedSegment.getId());
 
-    deserializedSegment = mapper.readValue(mapper.writeValueAsString(segment), DataSegment.class);
+    deserializedSegment = MAPPER.readValue(MAPPER.writeValueAsString(segment), DataSegment.class);
     Assert.assertEquals(0, segment.compareTo(deserializedSegment));
 
-    deserializedSegment = mapper.readValue(mapper.writeValueAsString(segment), DataSegment.class);
+    deserializedSegment = MAPPER.readValue(MAPPER.writeValueAsString(segment), DataSegment.class);
     Assert.assertEquals(0, deserializedSegment.compareTo(segment));
 
-    deserializedSegment = mapper.readValue(mapper.writeValueAsString(segment), DataSegment.class);
+    deserializedSegment = MAPPER.readValue(MAPPER.writeValueAsString(segment), DataSegment.class);
     Assert.assertEquals(segment.hashCode(), deserializedSegment.hashCode());
   }
 
@@ -224,7 +224,7 @@ public class DataSegmentTest
                                            .version(DateTimes.of("2012-01-01T11:22:33.444Z").toString())
                                            .build();
 
-    final DataSegment segment2 = mapper.readValue(mapper.writeValueAsString(segment), DataSegment.class);
+    final DataSegment segment2 = MAPPER.readValue(MAPPER.writeValueAsString(segment), DataSegment.class);
     Assert.assertEquals("empty dimensions", ImmutableList.of(), segment2.getDimensions());
     Assert.assertEquals("empty metrics", ImmutableList.of(), segment2.getMetrics());
   }

core/src/test/java/org/apache/druid/timeline/SegmentWithOvershadowedStatusTest.java

@@ -43,7 +43,7 @@ import java.util.Map;
 
 public class SegmentWithOvershadowedStatusTest
 {
-  private static final ObjectMapper mapper = new TestObjectMapper();
+  private static final ObjectMapper MAPPER = new TestObjectMapper();
   private static final int TEST_VERSION = 0x9;
 
   @Before
@@ -51,7 +51,7 @@ public class SegmentWithOvershadowedStatusTest
   {
     InjectableValues.Std injectableValues = new InjectableValues.Std();
     injectableValues.addValue(DataSegment.PruneLoadSpecHolder.class, DataSegment.PruneLoadSpecHolder.DEFAULT);
-    mapper.setInjectableValues(injectableValues);
+    MAPPER.setInjectableValues(injectableValues);
   }
 
   @Test
@@ -74,8 +74,8 @@ public class SegmentWithOvershadowedStatusTest
 
     final SegmentWithOvershadowedStatus segment = new SegmentWithOvershadowedStatus(dataSegment, false);
 
-    final Map<String, Object> objectMap = mapper.readValue(
+    final Map<String, Object> objectMap = MAPPER.readValue(
-        mapper.writeValueAsString(segment),
+        MAPPER.writeValueAsString(segment),
         JacksonUtils.TYPE_REFERENCE_MAP_STRING_OBJECT
     );
 
@@ -91,9 +91,9 @@ public class SegmentWithOvershadowedStatusTest
     Assert.assertEquals(1, objectMap.get("size"));
     Assert.assertEquals(false, objectMap.get("overshadowed"));
 
-    final String json = mapper.writeValueAsString(segment);
+    final String json = MAPPER.writeValueAsString(segment);
 
-    final TestSegmentWithOvershadowedStatus deserializedSegment = mapper.readValue(
+    final TestSegmentWithOvershadowedStatus deserializedSegment = MAPPER.readValue(
         json,
         TestSegmentWithOvershadowedStatus.class
     );

extensions-contrib/azure-extensions/src/test/java/org/apache/druid/storage/azure/AzureDataSegmentPullerTest.java

@@ -39,8 +39,8 @@ public class AzureDataSegmentPullerTest extends EasyMockSupport
 {
 
   private static final String SEGMENT_FILE_NAME = "segment";
-  private static final String containerName = "container";
+  private static final String CONTAINER_NAME = "container";
-  private static final String blobPath = "/path/to/storage/index.zip";
+  private static final String BLOB_PATH = "/path/to/storage/index.zip";
   private AzureStorage azureStorage;
 
   @Before
@@ -58,13 +58,13 @@ public class AzureDataSegmentPullerTest extends EasyMockSupport
     try {
       final InputStream zipStream = new FileInputStream(pulledFile);
 
-      EasyMock.expect(azureStorage.getBlobInputStream(containerName, blobPath)).andReturn(zipStream);
+      EasyMock.expect(azureStorage.getBlobInputStream(CONTAINER_NAME, BLOB_PATH)).andReturn(zipStream);
 
       replayAll();
 
       AzureDataSegmentPuller puller = new AzureDataSegmentPuller(azureStorage);
 
-      FileUtils.FileCopyResult result = puller.getSegmentFiles(containerName, blobPath, toDir);
+      FileUtils.FileCopyResult result = puller.getSegmentFiles(CONTAINER_NAME, BLOB_PATH, toDir);
 
       File expected = new File(toDir, SEGMENT_FILE_NAME);
       Assert.assertEquals(value.length(), result.size());
@@ -86,7 +86,7 @@ public class AzureDataSegmentPullerTest extends EasyMockSupport
 
     final File outDir = Files.createTempDirectory("druid").toFile();
     try {
-      EasyMock.expect(azureStorage.getBlobInputStream(containerName, blobPath)).andThrow(
+      EasyMock.expect(azureStorage.getBlobInputStream(CONTAINER_NAME, BLOB_PATH)).andThrow(
           new URISyntaxException(
               "error",
               "error",
@@ -98,7 +98,7 @@ public class AzureDataSegmentPullerTest extends EasyMockSupport
 
       AzureDataSegmentPuller puller = new AzureDataSegmentPuller(azureStorage);
 
-      puller.getSegmentFiles(containerName, blobPath, outDir);
+      puller.getSegmentFiles(CONTAINER_NAME, BLOB_PATH, outDir);
 
       Assert.assertFalse(outDir.exists());
 

extensions-contrib/azure-extensions/src/test/java/org/apache/druid/storage/azure/AzureDataSegmentPusherTest.java

@@ -50,13 +50,13 @@ public class AzureDataSegmentPusherTest extends EasyMockSupport
   @Rule
   public final TemporaryFolder tempFolder = new TemporaryFolder();
 
-  private static final String containerName = "container";
+  private static final String CONTAINER_NAME = "container";
-  private static final String blobPath = "test/2015-04-12T00:00:00.000Z_2015-04-13T00:00:00.000Z/1/0/index.zip";
+  private static final String BLOB_PATH = "test/2015-04-12T00:00:00.000Z_2015-04-13T00:00:00.000Z/1/0/index.zip";
-  private static final DataSegment dataSegment = new DataSegment(
+  private static final DataSegment DATA_SEGMENT = new DataSegment(
       "test",
       Intervals.of("2015-04-12/2015-04-13"),
       "1",
-      ImmutableMap.of("containerName", containerName, "blobPath", blobPath),
+      ImmutableMap.of("containerName", CONTAINER_NAME, "blobPath", BLOB_PATH),
       null,
       null,
       NoneShardSpec.instance(),
@@ -129,8 +129,8 @@ public class AzureDataSegmentPusherTest extends EasyMockSupport
   {
 
     AzureDataSegmentPusher pusher = new AzureDataSegmentPusher(azureStorage, azureAccountConfig);
-    final String storageDir = pusher.getStorageDir(dataSegment, false);
+    final String storageDir = pusher.getStorageDir(DATA_SEGMENT, false);
-    final String azurePath = pusher.getAzurePath(dataSegment, false);
+    final String azurePath = pusher.getAzurePath(DATA_SEGMENT, false);
 
     Assert.assertEquals(
         StringUtils.format("%s/%s", storageDir, AzureStorageDruidModule.INDEX_ZIP_FILE_NAME),
@@ -144,15 +144,15 @@ public class AzureDataSegmentPusherTest extends EasyMockSupport
     AzureDataSegmentPusher pusher = new AzureDataSegmentPusher(azureStorage, azureAccountConfig);
     final int binaryVersion = 9;
     final File compressedSegmentData = new File("index.zip");
-    final String azurePath = pusher.getAzurePath(dataSegment, false);
+    final String azurePath = pusher.getAzurePath(DATA_SEGMENT, false);
 
-    azureStorage.uploadBlob(compressedSegmentData, containerName, azurePath);
+    azureStorage.uploadBlob(compressedSegmentData, CONTAINER_NAME, azurePath);
     EasyMock.expectLastCall();
 
     replayAll();
 
     DataSegment pushedDataSegment = pusher.uploadDataSegment(
-        dataSegment,
+        DATA_SEGMENT,
         binaryVersion,
         0, // empty file
         compressedSegmentData,
@@ -180,7 +180,7 @@ public class AzureDataSegmentPusherTest extends EasyMockSupport
   public void storageDirContainsNoColonsTest()
   {
     AzureDataSegmentPusher pusher = new AzureDataSegmentPusher(azureStorage, azureAccountConfig);
-    DataSegment withColons = dataSegment.withVersion("2018-01-05T14:54:09.295Z");
+    DataSegment withColons = DATA_SEGMENT.withVersion("2018-01-05T14:54:09.295Z");
     String segmentPath = pusher.getStorageDir(withColons, false);
     Assert.assertFalse("Path should not contain any columns", segmentPath.contains(":"));
   }

extensions-contrib/azure-extensions/src/test/java/org/apache/druid/storage/azure/AzureTaskLogsTest.java

@@ -39,10 +39,10 @@ import java.nio.charset.StandardCharsets;
 public class AzureTaskLogsTest extends EasyMockSupport
 {
 
-  private static final String container = "test";
+  private static final String CONTAINER = "test";
-  private static final String prefix = "test/log";
+  private static final String PREFIX = "test/log";
-  private static final String taskid = "taskid";
+  private static final String TASK_ID = "taskid";
-  private static final AzureTaskLogsConfig azureTaskLogsConfig = new AzureTaskLogsConfig(container, prefix, 3);
+  private static final AzureTaskLogsConfig AZURE_TASK_LOGS_CONFIG = new AzureTaskLogsConfig(CONTAINER, PREFIX, 3);
 
   private AzureStorage azureStorage;
   private AzureTaskLogs azureTaskLogs;
@@ -51,7 +51,7 @@ public class AzureTaskLogsTest extends EasyMockSupport
   public void before()
   {
     azureStorage = createMock(AzureStorage.class);
-    azureTaskLogs = new AzureTaskLogs(azureTaskLogsConfig, azureStorage);
+    azureTaskLogs = new AzureTaskLogs(AZURE_TASK_LOGS_CONFIG, azureStorage);
   }
 
 
@@ -63,12 +63,12 @@ public class AzureTaskLogsTest extends EasyMockSupport
     try {
       final File logFile = new File(tmpDir, "log");
 
-      azureStorage.uploadBlob(logFile, container, prefix + "/" + taskid + "/log");
+      azureStorage.uploadBlob(logFile, CONTAINER, PREFIX + "/" + TASK_ID + "/log");
       EasyMock.expectLastCall();
 
       replayAll();
 
-      azureTaskLogs.pushTaskLog(taskid, logFile);
+      azureTaskLogs.pushTaskLog(TASK_ID, logFile);
 
       verifyAll();
     }
@@ -82,16 +82,16 @@ public class AzureTaskLogsTest extends EasyMockSupport
   {
     final String testLog = "hello this is a log";
 
-    final String blobPath = prefix + "/" + taskid + "/log";
+    final String blobPath = PREFIX + "/" + TASK_ID + "/log";
-    EasyMock.expect(azureStorage.getBlobExists(container, blobPath)).andReturn(true);
+    EasyMock.expect(azureStorage.getBlobExists(CONTAINER, blobPath)).andReturn(true);
-    EasyMock.expect(azureStorage.getBlobLength(container, blobPath)).andReturn((long) testLog.length());
+    EasyMock.expect(azureStorage.getBlobLength(CONTAINER, blobPath)).andReturn((long) testLog.length());
-    EasyMock.expect(azureStorage.getBlobInputStream(container, blobPath)).andReturn(
+    EasyMock.expect(azureStorage.getBlobInputStream(CONTAINER, blobPath)).andReturn(
         new ByteArrayInputStream(testLog.getBytes(StandardCharsets.UTF_8)));
 
 
     replayAll();
 
-    final Optional<ByteSource> byteSource = azureTaskLogs.streamTaskLog(taskid, 0);
+    final Optional<ByteSource> byteSource = azureTaskLogs.streamTaskLog(TASK_ID, 0);
 
     final StringWriter writer = new StringWriter();
     IOUtils.copy(byteSource.get().openStream(), writer, "UTF-8");
@@ -105,16 +105,16 @@ public class AzureTaskLogsTest extends EasyMockSupport
   {
     final String testLog = "hello this is a log";
 
-    final String blobPath = prefix + "/" + taskid + "/log";
+    final String blobPath = PREFIX + "/" + TASK_ID + "/log";
-    EasyMock.expect(azureStorage.getBlobExists(container, blobPath)).andReturn(true);
+    EasyMock.expect(azureStorage.getBlobExists(CONTAINER, blobPath)).andReturn(true);
-    EasyMock.expect(azureStorage.getBlobLength(container, blobPath)).andReturn((long) testLog.length());
+    EasyMock.expect(azureStorage.getBlobLength(CONTAINER, blobPath)).andReturn((long) testLog.length());
-    EasyMock.expect(azureStorage.getBlobInputStream(container, blobPath)).andReturn(
+    EasyMock.expect(azureStorage.getBlobInputStream(CONTAINER, blobPath)).andReturn(
         new ByteArrayInputStream(testLog.getBytes(StandardCharsets.UTF_8)));
 
 
     replayAll();
 
-    final Optional<ByteSource> byteSource = azureTaskLogs.streamTaskLog(taskid, 5);
+    final Optional<ByteSource> byteSource = azureTaskLogs.streamTaskLog(TASK_ID, 5);
 
     final StringWriter writer = new StringWriter();
     IOUtils.copy(byteSource.get().openStream(), writer, "UTF-8");
@@ -128,16 +128,16 @@ public class AzureTaskLogsTest extends EasyMockSupport
   {
     final String testLog = "hello this is a log";
 
-    final String blobPath = prefix + "/" + taskid + "/log";
+    final String blobPath = PREFIX + "/" + TASK_ID + "/log";
-    EasyMock.expect(azureStorage.getBlobExists(container, blobPath)).andReturn(true);
+    EasyMock.expect(azureStorage.getBlobExists(CONTAINER, blobPath)).andReturn(true);
-    EasyMock.expect(azureStorage.getBlobLength(container, blobPath)).andReturn((long) testLog.length());
+    EasyMock.expect(azureStorage.getBlobLength(CONTAINER, blobPath)).andReturn((long) testLog.length());
-    EasyMock.expect(azureStorage.getBlobInputStream(container, blobPath)).andReturn(
+    EasyMock.expect(azureStorage.getBlobInputStream(CONTAINER, blobPath)).andReturn(
         new ByteArrayInputStream(StringUtils.toUtf8(testLog)));
 
 
     replayAll();
 
-    final Optional<ByteSource> byteSource = azureTaskLogs.streamTaskLog(taskid, -3);
+    final Optional<ByteSource> byteSource = azureTaskLogs.streamTaskLog(TASK_ID, -3);
 
     final StringWriter writer = new StringWriter();
     IOUtils.copy(byteSource.get().openStream(), writer, "UTF-8");

extensions-contrib/distinctcount/src/main/java/org/apache/druid/query/aggregation/distinctcount/ConciseBitMapFactory.java

@@ -25,7 +25,7 @@ import org.apache.druid.collections.bitmap.MutableBitmap;
 
 public class ConciseBitMapFactory implements BitMapFactory
 {
-  private static final BitmapFactory bitmapFactory = new ConciseBitmapFactory();
+  private static final BitmapFactory BITMAP_FACTORY = new ConciseBitmapFactory();
 
   public ConciseBitMapFactory()
   {
@@ -34,7 +34,7 @@ public class ConciseBitMapFactory implements BitMapFactory
   @Override
   public MutableBitmap makeEmptyMutableBitmap()
   {
-    return bitmapFactory.makeEmptyMutableBitmap();
+    return BITMAP_FACTORY.makeEmptyMutableBitmap();
   }
 
   @Override

extensions-contrib/distinctcount/src/main/java/org/apache/druid/query/aggregation/distinctcount/JavaBitMapFactory.java

@@ -25,7 +25,7 @@ import org.apache.druid.collections.bitmap.MutableBitmap;
 
 public class JavaBitMapFactory implements BitMapFactory
 {
-  private static final BitmapFactory bitmapFactory = new BitSetBitmapFactory();
+  private static final BitmapFactory BITMAP_FACTORY = new BitSetBitmapFactory();
 
   public JavaBitMapFactory()
   {
@@ -34,7 +34,7 @@ public class JavaBitMapFactory implements BitMapFactory
   @Override
   public MutableBitmap makeEmptyMutableBitmap()
   {
-    return bitmapFactory.makeEmptyMutableBitmap();
+    return BITMAP_FACTORY.makeEmptyMutableBitmap();
   }
 
   @Override

extensions-contrib/distinctcount/src/main/java/org/apache/druid/query/aggregation/distinctcount/RoaringBitMapFactory.java

@@ -25,7 +25,7 @@ import org.apache.druid.collections.bitmap.RoaringBitmapFactory;
 
 public class RoaringBitMapFactory implements BitMapFactory
 {
-  private static final BitmapFactory bitmapFactory = new RoaringBitmapFactory();
+  private static final BitmapFactory BITMAP_FACTORY = new RoaringBitmapFactory();
 
   public RoaringBitMapFactory()
   {
@@ -34,7 +34,7 @@ public class RoaringBitMapFactory implements BitMapFactory
   @Override
   public MutableBitmap makeEmptyMutableBitmap()
   {
-    return bitmapFactory.makeEmptyMutableBitmap();
+    return BITMAP_FACTORY.makeEmptyMutableBitmap();
   }
 
   @Override

extensions-contrib/distinctcount/src/test/java/org/apache/druid/query/aggregation/distinctcount/DistinctCountGroupByQueryTest.java

@@ -113,20 +113,20 @@ public class DistinctCountGroupByQueryTest
     );
 
     GroupByQuery query = new GroupByQuery.Builder()
-        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setDataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .setGranularity(QueryRunnerTestHelper.allGran)
+        .setGranularity(QueryRunnerTestHelper.ALL_GRAN)
         .setDimensions(new DefaultDimensionSpec(
             client_type,
             client_type
         ))
-        .setInterval(QueryRunnerTestHelper.fullOnIntervalSpec)
+        .setInterval(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
         .setLimitSpec(
             new DefaultLimitSpec(
                 Collections.singletonList(new OrderByColumnSpec(client_type, OrderByColumnSpec.Direction.DESCENDING)),
                 10
             )
         )
-        .setAggregatorSpecs(QueryRunnerTestHelper.rowsCount, new DistinctCountAggregatorFactory("UV", visitor_id, null))
+        .setAggregatorSpecs(QueryRunnerTestHelper.ROWS_COUNT, new DistinctCountAggregatorFactory("UV", visitor_id, null))
         .build();
     final Segment incrementalIndexSegment = new IncrementalIndexSegment(index, null);
 

extensions-contrib/distinctcount/src/test/java/org/apache/druid/query/aggregation/distinctcount/DistinctCountTimeseriesQueryTest.java

@@ -86,12 +86,12 @@ public class DistinctCountTimeseriesQueryTest
     );
 
     TimeseriesQuery query = Druids.newTimeseriesQueryBuilder()
-                                  .dataSource(QueryRunnerTestHelper.dataSource)
+                                  .dataSource(QueryRunnerTestHelper.DATA_SOURCE)
-                                  .granularity(QueryRunnerTestHelper.allGran)
+                                  .granularity(QueryRunnerTestHelper.ALL_GRAN)
-                                  .intervals(QueryRunnerTestHelper.fullOnIntervalSpec)
+                                  .intervals(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
                                   .aggregators(
                                       Lists.newArrayList(
-                                          QueryRunnerTestHelper.rowsCount,
+                                          QueryRunnerTestHelper.ROWS_COUNT,
                                           new DistinctCountAggregatorFactory("UV", visitor_id, null)
                                       )
                                   )

extensions-contrib/distinctcount/src/test/java/org/apache/druid/query/aggregation/distinctcount/DistinctCountTopNQueryTest.java

@@ -115,14 +115,14 @@ public class DistinctCountTopNQueryTest
         )
     );
 
-    TopNQuery query = new TopNQueryBuilder().dataSource(QueryRunnerTestHelper.dataSource)
+    TopNQuery query = new TopNQueryBuilder().dataSource(QueryRunnerTestHelper.DATA_SOURCE)
-                          .granularity(QueryRunnerTestHelper.allGran)
+                          .granularity(QueryRunnerTestHelper.ALL_GRAN)
-                          .intervals(QueryRunnerTestHelper.fullOnIntervalSpec)
+                          .intervals(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
                           .dimension(client_type)
                           .metric("UV")
                           .threshold(10)
                           .aggregators(
-                              QueryRunnerTestHelper.rowsCount,
+                              QueryRunnerTestHelper.ROWS_COUNT,
                               new DistinctCountAggregatorFactory("UV", visitor_id, null)
                           )
                           .build();

extensions-contrib/materialized-view-selection/src/main/java/org/apache/druid/query/materializedview/DerivativeDataSourceManager.java

@@ -69,7 +69,7 @@ import java.util.stream.Collectors;
 public class DerivativeDataSourceManager 
 {
   private static final EmittingLogger log = new EmittingLogger(DerivativeDataSourceManager.class);
-  private static final AtomicReference<ConcurrentHashMap<String, SortedSet<DerivativeDataSource>>> derivativesRef =
+  private static final AtomicReference<ConcurrentHashMap<String, SortedSet<DerivativeDataSource>>> DERIVATIVES_REF =
       new AtomicReference<>(new ConcurrentHashMap<>());
   private final MaterializedViewConfig config;
   private final Supplier<MetadataStorageTablesConfig> dbTables;
@@ -137,7 +137,7 @@ public class DerivativeDataSourceManager
       started = false;
       future.cancel(true);
       future = null;
-      derivativesRef.set(new ConcurrentHashMap<>());
+      DERIVATIVES_REF.set(new ConcurrentHashMap<>());
       exec.shutdownNow();
       exec = null;
     }
@@ -145,12 +145,12 @@ public class DerivativeDataSourceManager
 
   public static ImmutableSet<DerivativeDataSource> getDerivatives(String datasource)
   {
-    return ImmutableSet.copyOf(derivativesRef.get().getOrDefault(datasource, new TreeSet<>()));
+    return ImmutableSet.copyOf(DERIVATIVES_REF.get().getOrDefault(datasource, new TreeSet<>()));
   }
 
   public static ImmutableMap<String, Set<DerivativeDataSource>> getAllDerivatives()
   {
-    return ImmutableMap.copyOf(derivativesRef.get());
+    return ImmutableMap.copyOf(DERIVATIVES_REF.get());
   }
 
   private void updateDerivatives()
@@ -205,8 +205,8 @@ public class DerivativeDataSourceManager
     }
     ConcurrentHashMap<String, SortedSet<DerivativeDataSource>> current;
     do {
-      current = derivativesRef.get();
+      current = DERIVATIVES_REF.get();
-    } while (!derivativesRef.compareAndSet(current, newDerivatives));
+    } while (!DERIVATIVES_REF.compareAndSet(current, newDerivatives));
   }
 
   /**

extensions-contrib/materialized-view-selection/src/test/java/org/apache/druid/query/materializedview/DatasourceOptimizerTest.java

@@ -203,7 +203,7 @@ public class DatasourceOptimizerTest extends CuratorTestBase
     // build user query
     TopNQuery userQuery = new TopNQueryBuilder()
         .dataSource("base")
-        .granularity(QueryRunnerTestHelper.allGran)
+        .granularity(QueryRunnerTestHelper.ALL_GRAN)
         .dimension("dim1")
         .metric("cost")
         .threshold(4)
@@ -214,7 +214,7 @@ public class DatasourceOptimizerTest extends CuratorTestBase
     List<Query> expectedQueryAfterOptimizing = Lists.newArrayList(
         new TopNQueryBuilder()
             .dataSource("derivative")
-            .granularity(QueryRunnerTestHelper.allGran)
+            .granularity(QueryRunnerTestHelper.ALL_GRAN)
             .dimension("dim1")
             .metric("cost")
             .threshold(4)
@@ -223,7 +223,7 @@ public class DatasourceOptimizerTest extends CuratorTestBase
             .build(),
         new TopNQueryBuilder()
             .dataSource("base")
-            .granularity(QueryRunnerTestHelper.allGran)
+            .granularity(QueryRunnerTestHelper.ALL_GRAN)
             .dimension("dim1")
             .metric("cost")
             .threshold(4)

extensions-contrib/materialized-view-selection/src/test/java/org/apache/druid/query/materializedview/MaterializedViewQueryQueryToolChestTest.java

@@ -44,10 +44,10 @@ public class MaterializedViewQueryQueryToolChestTest
   public void testMakePostComputeManipulatorFn()
   {
     TimeseriesQuery realQuery = Druids.newTimeseriesQueryBuilder()
-                                        .dataSource(QueryRunnerTestHelper.dataSource)
+                                        .dataSource(QueryRunnerTestHelper.DATA_SOURCE)
-                                        .granularity(QueryRunnerTestHelper.dayGran)
+                                        .granularity(QueryRunnerTestHelper.DAY_GRAN)
-                                        .intervals(QueryRunnerTestHelper.fullOnIntervalSpec)
+                                        .intervals(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
-                                        .aggregators(QueryRunnerTestHelper.rowsCount)
+                                        .aggregators(QueryRunnerTestHelper.ROWS_COUNT)
                                         .descending(true)
                                         .build();
     MaterializedViewQuery materializedViewQuery = new MaterializedViewQuery(realQuery, null);
@@ -87,7 +87,7 @@ public class MaterializedViewQueryQueryToolChestTest
 
     Assert.assertEquals(postResult.getTimestamp(), result.getTimestamp());
     Assert.assertEquals(postResultMap.size(), 2);
-    Assert.assertEquals(postResultMap.get(QueryRunnerTestHelper.rowsCount.getName()), "metricvalue1");
+    Assert.assertEquals(postResultMap.get(QueryRunnerTestHelper.ROWS_COUNT.getName()), "metricvalue1");
     Assert.assertEquals(postResultMap.get("dim1"), "dimvalue1");
   }
 }

extensions-contrib/materialized-view-selection/src/test/java/org/apache/druid/query/materializedview/MaterializedViewQueryTest.java

@@ -43,15 +43,15 @@ import java.io.IOException;
 
 public class MaterializedViewQueryTest
 {
-  private static final ObjectMapper jsonMapper = TestHelper.makeJsonMapper();
+  private static final ObjectMapper JSON_MAPPER = TestHelper.makeJsonMapper();
   private DataSourceOptimizer optimizer;
 
   @Before
   public void setUp()
   {
-    jsonMapper.registerSubtypes(new NamedType(MaterializedViewQuery.class, MaterializedViewQuery.TYPE));
+    JSON_MAPPER.registerSubtypes(new NamedType(MaterializedViewQuery.class, MaterializedViewQuery.TYPE));
     optimizer = EasyMock.createMock(DataSourceOptimizer.class);
-    jsonMapper.setInjectableValues(
+    JSON_MAPPER.setInjectableValues(
         new InjectableValues.Std()
             .addValue(ExprMacroTable.class.getName(), LookupEnabledTestExprMacroTable.INSTANCE)
             .addValue(DataSourceOptimizer.class, optimizer)
@@ -62,16 +62,16 @@ public class MaterializedViewQueryTest
   public void testQuerySerialization() throws IOException
   {
     TopNQuery topNQuery = new TopNQueryBuilder()
-        .dataSource(QueryRunnerTestHelper.dataSource)
+        .dataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .granularity(QueryRunnerTestHelper.allGran)
+        .granularity(QueryRunnerTestHelper.ALL_GRAN)
-        .dimension(QueryRunnerTestHelper.marketDimension)
+        .dimension(QueryRunnerTestHelper.MARKET_DIMENSION)
-        .metric(QueryRunnerTestHelper.indexMetric)
+        .metric(QueryRunnerTestHelper.INDEX_METRIC)
         .threshold(4)
-        .intervals(QueryRunnerTestHelper.fullOnIntervalSpec)
+        .intervals(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
         .aggregators(
             Lists.newArrayList(
                 Iterables.concat(
-                    QueryRunnerTestHelper.commonDoubleAggregators,
+                    QueryRunnerTestHelper.COMMON_DOUBLE_AGGREGATORS,
                     Lists.newArrayList(
                         new DoubleMaxAggregatorFactory("maxIndex", "index"),
                         new DoubleMinAggregatorFactory("minIndex", "index")
@@ -79,14 +79,14 @@ public class MaterializedViewQueryTest
                 )
             )
         )
-        .postAggregators(QueryRunnerTestHelper.addRowsIndexConstant)
+        .postAggregators(QueryRunnerTestHelper.ADD_ROWS_INDEX_CONSTANT)
         .build();
     MaterializedViewQuery query = new MaterializedViewQuery(topNQuery, optimizer);
-    String json = jsonMapper.writeValueAsString(query);
+    String json = JSON_MAPPER.writeValueAsString(query);
-    Query serdeQuery = jsonMapper.readValue(json, Query.class);
+    Query serdeQuery = JSON_MAPPER.readValue(json, Query.class);
     Assert.assertEquals(query, serdeQuery);
-    Assert.assertEquals(new TableDataSource(QueryRunnerTestHelper.dataSource), query.getDataSource());
+    Assert.assertEquals(new TableDataSource(QueryRunnerTestHelper.DATA_SOURCE), query.getDataSource());
-    Assert.assertEquals(QueryRunnerTestHelper.allGran, query.getGranularity());
+    Assert.assertEquals(QueryRunnerTestHelper.ALL_GRAN, query.getGranularity());
-    Assert.assertEquals(QueryRunnerTestHelper.fullOnIntervalSpec.getIntervals(), query.getIntervals());
+    Assert.assertEquals(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC.getIntervals(), query.getIntervals());
   }
 }

extensions-contrib/moving-average-query/src/test/java/org/apache/druid/query/movingaverage/MovingAverageIterableTest.java

@@ -60,22 +60,22 @@ public class MovingAverageIterableTest
   private static final String AGE = "age";
   private static final String COUNTRY = "country";
 
-  private static final Map<String, Object> dims1 = new HashMap<>();
+  private static final Map<String, Object> DIMS1 = new HashMap<>();
-  private static final Map<String, Object> dims2 = new HashMap<>();
+  private static final Map<String, Object> DIMS2 = new HashMap<>();
-  private static final Map<String, Object> dims3 = new HashMap<>();
+  private static final Map<String, Object> DIMS3 = new HashMap<>();
 
   static {
-    dims1.put(GENDER, "m");
+    DIMS1.put(GENDER, "m");
-    dims1.put(AGE, "10");
+    DIMS1.put(AGE, "10");
-    dims1.put(COUNTRY, "US");
+    DIMS1.put(COUNTRY, "US");
 
-    dims2.put(GENDER, "f");
+    DIMS2.put(GENDER, "f");
-    dims2.put(AGE, "8");
+    DIMS2.put(AGE, "8");
-    dims2.put(COUNTRY, "US");
+    DIMS2.put(COUNTRY, "US");
 
-    dims3.put(GENDER, "u");
+    DIMS3.put(GENDER, "u");
-    dims3.put(AGE, "5");
+    DIMS3.put(AGE, "5");
-    dims3.put(COUNTRY, "UK");
+    DIMS3.put(COUNTRY, "UK");
   }
 
   @Test
@@ -90,16 +90,16 @@ public class MovingAverageIterableTest
 
     Sequence<RowBucket> dayBuckets = Sequences.simple(Arrays.asList(
         new RowBucket(JAN_1, Arrays.asList(
-            new MapBasedRow(JAN_1, dims1),
+            new MapBasedRow(JAN_1, DIMS1),
-            new MapBasedRow(JAN_1, dims2)
+            new MapBasedRow(JAN_1, DIMS2)
         )),
         new RowBucket(JAN_2, Collections.singletonList(
-            new MapBasedRow(JAN_2, dims1)
+            new MapBasedRow(JAN_2, DIMS1)
         )),
         new RowBucket(JAN_3, Collections.emptyList()),
         new RowBucket(JAN_4, Arrays.asList(
-            new MapBasedRow(JAN_4, dims2),
+            new MapBasedRow(JAN_4, DIMS2),
-            new MapBasedRow(JAN_4, dims3)
+            new MapBasedRow(JAN_4, DIMS3)
         ))
     ));
 

extensions-contrib/virtual-columns/src/test/java/org/apache/druid/segment/MapVirtualColumnGroupByTest.java

@@ -125,7 +125,7 @@ public class MapVirtualColumnGroupByTest
   public void testWithMapColumn()
   {
     final GroupByQuery query = new GroupByQuery(
-        new TableDataSource(QueryRunnerTestHelper.dataSource),
+        new TableDataSource(QueryRunnerTestHelper.DATA_SOURCE),
         new MultipleIntervalSegmentSpec(ImmutableList.of(Intervals.of("2011/2012"))),
         VirtualColumns.create(ImmutableList.of(new MapVirtualColumn("keys", "values", "params"))),
         null,
@@ -148,7 +148,7 @@ public class MapVirtualColumnGroupByTest
   public void testWithSubColumn()
   {
     final GroupByQuery query = new GroupByQuery(
-        new TableDataSource(QueryRunnerTestHelper.dataSource),
+        new TableDataSource(QueryRunnerTestHelper.DATA_SOURCE),
         new MultipleIntervalSegmentSpec(ImmutableList.of(Intervals.of("2011/2012"))),
         VirtualColumns.create(ImmutableList.of(new MapVirtualColumn("keys", "values", "params"))),
         null,

extensions-contrib/virtual-columns/src/test/java/org/apache/druid/segment/MapVirtualColumnSelectTest.java

@@ -133,9 +133,9 @@ public class MapVirtualColumnSelectTest
   private Druids.SelectQueryBuilder testBuilder()
   {
     return Druids.newSelectQueryBuilder()
-                 .dataSource(QueryRunnerTestHelper.dataSource)
+                 .dataSource(QueryRunnerTestHelper.DATA_SOURCE)
-                 .granularity(QueryRunnerTestHelper.allGran)
+                 .granularity(QueryRunnerTestHelper.ALL_GRAN)
-                 .intervals(QueryRunnerTestHelper.fullOnIntervalSpec)
+                 .intervals(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
                  .pagingSpec(new PagingSpec(null, 3));
   }
 
@@ -197,7 +197,7 @@ public class MapVirtualColumnSelectTest
     Assert.assertEquals(expected.size(), events.size());
     for (int i = 0; i < events.size(); i++) {
       Map event = events.get(i).getEvent();
-      event.remove(EventHolder.timestampKey);
+      event.remove(EventHolder.TIMESTAMP_KEY);
       Assert.assertEquals(expected.get(i), event);
     }
   }

extensions-contrib/virtual-columns/src/test/java/org/apache/druid/segment/MapVirtualColumnTopNTest.java

@@ -85,7 +85,7 @@ public class MapVirtualColumnTopNTest
   public void testWithMapColumn()
   {
     final TopNQuery query = new TopNQuery(
-        new TableDataSource(QueryRunnerTestHelper.dataSource),
+        new TableDataSource(QueryRunnerTestHelper.DATA_SOURCE),
         VirtualColumns.create(
             ImmutableList.of(
                 new MapVirtualColumn("keys", "values", "params")
@@ -111,7 +111,7 @@ public class MapVirtualColumnTopNTest
   public void testWithSubColumn()
   {
     final TopNQuery query = new TopNQuery(
-        new TableDataSource(QueryRunnerTestHelper.dataSource),
+        new TableDataSource(QueryRunnerTestHelper.DATA_SOURCE),
         VirtualColumns.create(
             ImmutableList.of(
                 new MapVirtualColumn("keys", "values", "params")

extensions-core/datasketches/src/main/java/org/apache/druid/query/aggregation/datasketches/quantiles/DoublesSketchComplexMetricSerde.java

@@ -39,7 +39,7 @@ import java.nio.ByteBuffer;
 public class DoublesSketchComplexMetricSerde extends ComplexMetricSerde
 {
 
-  private static final DoublesSketchObjectStrategy strategy = new DoublesSketchObjectStrategy();
+  private static final DoublesSketchObjectStrategy STRATEGY = new DoublesSketchObjectStrategy();
 
   @Override
   public String getTypeName()
@@ -50,7 +50,7 @@ public class DoublesSketchComplexMetricSerde extends ComplexMetricSerde
   @Override
   public ObjectStrategy<DoublesSketch> getObjectStrategy()
   {
-    return strategy;
+    return STRATEGY;
   }
 
   @Override
@@ -105,7 +105,7 @@ public class DoublesSketchComplexMetricSerde extends ComplexMetricSerde
   @Override
   public void deserializeColumn(final ByteBuffer buffer, final ColumnBuilder builder)
   {
-    final GenericIndexed<DoublesSketch> column = GenericIndexed.read(buffer, strategy, builder.getFileMapper());
+    final GenericIndexed<DoublesSketch> column = GenericIndexed.read(buffer, STRATEGY, builder.getFileMapper());
     builder.setComplexColumnSupplier(new ComplexColumnPartSupplier(getTypeName(), column));
   }
 

extensions-core/druid-bloom-filter/src/test/java/org/apache/druid/query/aggregation/bloom/BloomFilterAggregatorTest.java

@@ -57,14 +57,14 @@ import java.util.stream.IntStream;
 
 public class BloomFilterAggregatorTest
 {
-  private static final String nullish = NullHandling.replaceWithDefault() ? "" : null;
+  private static final String NULLISH = NullHandling.replaceWithDefault() ? "" : null;
-  private static final List<String[]> values1 = dimensionValues(
+  private static final List<String[]> VALUES1 = dimensionValues(
       "a",
       "b",
       "c",
       "a",
       "a",
-      nullish,
+      NULLISH,
       "b",
       "b",
       "b",
@@ -72,7 +72,7 @@ public class BloomFilterAggregatorTest
       "a",
       "a"
   );
-  private static final List<String[]> values2 = dimensionValues(
+  private static final List<String[]> VALUES2 = dimensionValues(
       "a",
       "b",
       "c",
@@ -80,17 +80,17 @@ public class BloomFilterAggregatorTest
       "a",
       "e",
       "b",
-      new String[]{nullish, "x"},
+      new String[]{NULLISH, "x"},
-      new String[]{"x", nullish},
+      new String[]{"x", NULLISH},
       new String[]{"y", "x"},
       new String[]{"x", "y"},
       new String[]{"x", "y", "a"}
   );
-  private static final Double[] doubleValues1 = new Double[]{0.1, 1.5, 18.3, 0.1};
+  private static final Double[] DOUBLE_VALUES1 = new Double[]{0.1, 1.5, 18.3, 0.1};
-  private static final Float[] floatValues1 = new Float[]{0.4f, 0.8f, 23.2f};
+  private static final Float[] FLOAT_VALUES1 = new Float[]{0.4f, 0.8f, 23.2f};
-  private static final Long[] longValues1 = new Long[]{10241L, 12312355L, 0L, 81L};
+  private static final Long[] LONG_VALUES1 = new Long[]{10241L, 12312355L, 0L, 81L};
 
-  private static final int maxNumValues = 15;
+  private static final int MAX_NUM_VALUES = 15;
 
   private static BloomKFilter filter1;
   private static BloomKFilter filter2;
@@ -104,31 +104,31 @@ public class BloomFilterAggregatorTest
 
   static {
     try {
-      filter1 = new BloomKFilter(maxNumValues);
+      filter1 = new BloomKFilter(MAX_NUM_VALUES);
-      filter2 = new BloomKFilter(maxNumValues);
+      filter2 = new BloomKFilter(MAX_NUM_VALUES);
-      BloomKFilter combinedValuesFilter = new BloomKFilter(maxNumValues);
+      BloomKFilter combinedValuesFilter = new BloomKFilter(MAX_NUM_VALUES);
 
-      createStringFilter(values1, filter1, combinedValuesFilter);
+      createStringFilter(VALUES1, filter1, combinedValuesFilter);
-      createStringFilter(values2, filter2, combinedValuesFilter);
+      createStringFilter(VALUES2, filter2, combinedValuesFilter);
 
       serializedFilter1 = filterToString(filter1);
       serializedFilter2 = filterToString(filter2);
       serializedCombinedFilter = filterToString(combinedValuesFilter);
 
-      BloomKFilter longFilter = new BloomKFilter(maxNumValues);
+      BloomKFilter longFilter = new BloomKFilter(MAX_NUM_VALUES);
-      for (long val : longValues1) {
+      for (long val : LONG_VALUES1) {
         longFilter.addLong(val);
       }
       serializedLongFilter = filterToString(longFilter);
 
-      BloomKFilter floatFilter = new BloomKFilter(maxNumValues);
+      BloomKFilter floatFilter = new BloomKFilter(MAX_NUM_VALUES);
-      for (float val : floatValues1) {
+      for (float val : FLOAT_VALUES1) {
         floatFilter.addFloat(val);
       }
       serializedFloatFilter = filterToString(floatFilter);
 
-      BloomKFilter doubleFilter = new BloomKFilter(maxNumValues);
+      BloomKFilter doubleFilter = new BloomKFilter(MAX_NUM_VALUES);
-      for (double val : doubleValues1) {
+      for (double val : DOUBLE_VALUES1) {
         doubleFilter.addDouble(val);
       }
       serializedDoubleFilter = filterToString(doubleFilter);
@@ -232,7 +232,7 @@ public class BloomFilterAggregatorTest
     valueAggregatorFactory = new BloomFilterAggregatorFactory(
         "billy",
         dimSpec,
-        maxNumValues
+        MAX_NUM_VALUES
     );
   }
 
@@ -240,10 +240,10 @@ public class BloomFilterAggregatorTest
   @Test
   public void testAggregateValues() throws IOException
   {
-    DimensionSelector dimSelector = new CardinalityAggregatorTest.TestDimensionSelector(values1, null);
+    DimensionSelector dimSelector = new CardinalityAggregatorTest.TestDimensionSelector(VALUES1, null);
-    StringBloomFilterAggregator agg = new StringBloomFilterAggregator(dimSelector, maxNumValues, true);
+    StringBloomFilterAggregator agg = new StringBloomFilterAggregator(dimSelector, MAX_NUM_VALUES, true);
 
-    for (int i = 0; i < values1.size(); ++i) {
+    for (int i = 0; i < VALUES1.size(); ++i) {
       aggregateDimension(Collections.singletonList(dimSelector), agg);
     }
 
@@ -257,10 +257,10 @@ public class BloomFilterAggregatorTest
   @Test
   public void testAggregateLongValues() throws IOException
   {
-    TestLongColumnSelector selector = new TestLongColumnSelector(Arrays.asList(longValues1));
+    TestLongColumnSelector selector = new TestLongColumnSelector(Arrays.asList(LONG_VALUES1));
-    LongBloomFilterAggregator agg = new LongBloomFilterAggregator(selector, maxNumValues, true);
+    LongBloomFilterAggregator agg = new LongBloomFilterAggregator(selector, MAX_NUM_VALUES, true);
 
-    for (Long ignored : longValues1) {
+    for (Long ignored : LONG_VALUES1) {
       aggregateColumn(Collections.singletonList(selector), agg);
     }
 
@@ -274,10 +274,10 @@ public class BloomFilterAggregatorTest
   @Test
   public void testAggregateFloatValues() throws IOException
   {
-    TestFloatColumnSelector selector = new TestFloatColumnSelector(Arrays.asList(floatValues1));
+    TestFloatColumnSelector selector = new TestFloatColumnSelector(Arrays.asList(FLOAT_VALUES1));
-    FloatBloomFilterAggregator agg = new FloatBloomFilterAggregator(selector, maxNumValues, true);
+    FloatBloomFilterAggregator agg = new FloatBloomFilterAggregator(selector, MAX_NUM_VALUES, true);
 
-    for (Float ignored : floatValues1) {
+    for (Float ignored : FLOAT_VALUES1) {
       aggregateColumn(Collections.singletonList(selector), agg);
     }
 
@@ -291,10 +291,10 @@ public class BloomFilterAggregatorTest
   @Test
   public void testAggregateDoubleValues() throws IOException
   {
-    TestDoubleColumnSelector selector = new TestDoubleColumnSelector(Arrays.asList(doubleValues1));
+    TestDoubleColumnSelector selector = new TestDoubleColumnSelector(Arrays.asList(DOUBLE_VALUES1));
-    DoubleBloomFilterAggregator agg = new DoubleBloomFilterAggregator(selector, maxNumValues, true);
+    DoubleBloomFilterAggregator agg = new DoubleBloomFilterAggregator(selector, MAX_NUM_VALUES, true);
 
-    for (Double ignored : doubleValues1) {
+    for (Double ignored : DOUBLE_VALUES1) {
       aggregateColumn(Collections.singletonList(selector), agg);
     }
 
@@ -308,8 +308,8 @@ public class BloomFilterAggregatorTest
   @Test
   public void testBufferAggregateStringValues() throws IOException
   {
-    DimensionSelector dimSelector = new CardinalityAggregatorTest.TestDimensionSelector(values2, null);
+    DimensionSelector dimSelector = new CardinalityAggregatorTest.TestDimensionSelector(VALUES2, null);
-    StringBloomFilterAggregator agg = new StringBloomFilterAggregator(dimSelector, maxNumValues, true);
+    StringBloomFilterAggregator agg = new StringBloomFilterAggregator(dimSelector, MAX_NUM_VALUES, true);
 
     int maxSize = valueAggregatorFactory.getMaxIntermediateSizeWithNulls();
     ByteBuffer buf = ByteBuffer.allocate(maxSize + 64);
@@ -318,7 +318,7 @@ public class BloomFilterAggregatorTest
 
     agg.init(buf, pos);
 
-    for (int i = 0; i < values2.size(); ++i) {
+    for (int i = 0; i < VALUES2.size(); ++i) {
       bufferAggregateDimension(Collections.singletonList(dimSelector), agg, buf, pos);
     }
     BloomKFilter bloomKFilter = BloomKFilter.deserialize(
@@ -331,8 +331,8 @@ public class BloomFilterAggregatorTest
   @Test
   public void testBufferAggregateLongValues() throws IOException
   {
-    TestLongColumnSelector selector = new TestLongColumnSelector(Arrays.asList(longValues1));
+    TestLongColumnSelector selector = new TestLongColumnSelector(Arrays.asList(LONG_VALUES1));
-    LongBloomFilterAggregator agg = new LongBloomFilterAggregator(selector, maxNumValues, true);
+    LongBloomFilterAggregator agg = new LongBloomFilterAggregator(selector, MAX_NUM_VALUES, true);
 
     int maxSize = valueAggregatorFactory.getMaxIntermediateSizeWithNulls();
     ByteBuffer buf = ByteBuffer.allocate(maxSize + 64);
@@ -341,7 +341,7 @@ public class BloomFilterAggregatorTest
 
     agg.init(buf, pos);
 
-    IntStream.range(0, longValues1.length)
+    IntStream.range(0, LONG_VALUES1.length)
              .forEach(i -> bufferAggregateColumn(Collections.singletonList(selector), agg, buf, pos));
     BloomKFilter bloomKFilter = BloomKFilter.deserialize(
         (ByteBuffer) valueAggregatorFactory.finalizeComputation(agg.get(buf, pos))
@@ -353,8 +353,8 @@ public class BloomFilterAggregatorTest
   @Test
   public void testBufferAggregateFloatValues() throws IOException
   {
-    TestFloatColumnSelector selector = new TestFloatColumnSelector(Arrays.asList(floatValues1));
+    TestFloatColumnSelector selector = new TestFloatColumnSelector(Arrays.asList(FLOAT_VALUES1));
-    FloatBloomFilterAggregator agg = new FloatBloomFilterAggregator(selector, maxNumValues, true);
+    FloatBloomFilterAggregator agg = new FloatBloomFilterAggregator(selector, MAX_NUM_VALUES, true);
 
     int maxSize = valueAggregatorFactory.getMaxIntermediateSizeWithNulls();
     ByteBuffer buf = ByteBuffer.allocate(maxSize + 64);
@@ -363,7 +363,7 @@ public class BloomFilterAggregatorTest
 
     agg.init(buf, pos);
 
-    IntStream.range(0, floatValues1.length)
+    IntStream.range(0, FLOAT_VALUES1.length)
              .forEach(i -> bufferAggregateColumn(Collections.singletonList(selector), agg, buf, pos));
     BloomKFilter bloomKFilter = BloomKFilter.deserialize(
         (ByteBuffer) valueAggregatorFactory.finalizeComputation(agg.get(buf, pos))
@@ -375,8 +375,8 @@ public class BloomFilterAggregatorTest
   @Test
   public void testBufferAggregateDoubleValues() throws IOException
   {
-    TestDoubleColumnSelector selector = new TestDoubleColumnSelector(Arrays.asList(doubleValues1));
+    TestDoubleColumnSelector selector = new TestDoubleColumnSelector(Arrays.asList(DOUBLE_VALUES1));
-    DoubleBloomFilterAggregator agg = new DoubleBloomFilterAggregator(selector, maxNumValues, true);
+    DoubleBloomFilterAggregator agg = new DoubleBloomFilterAggregator(selector, MAX_NUM_VALUES, true);
 
     int maxSize = valueAggregatorFactory.getMaxIntermediateSizeWithNulls();
     ByteBuffer buf = ByteBuffer.allocate(maxSize + 64);
@@ -385,7 +385,7 @@ public class BloomFilterAggregatorTest
 
     agg.init(buf, pos);
 
-    IntStream.range(0, doubleValues1.length)
+    IntStream.range(0, DOUBLE_VALUES1.length)
              .forEach(i -> bufferAggregateColumn(Collections.singletonList(selector), agg, buf, pos));
     BloomKFilter bloomKFilter = BloomKFilter.deserialize(
         (ByteBuffer) valueAggregatorFactory.finalizeComputation(agg.get(buf, pos))
@@ -397,16 +397,16 @@ public class BloomFilterAggregatorTest
   @Test
   public void testCombineValues() throws IOException
   {
-    DimensionSelector dimSelector1 = new CardinalityAggregatorTest.TestDimensionSelector(values1, null);
+    DimensionSelector dimSelector1 = new CardinalityAggregatorTest.TestDimensionSelector(VALUES1, null);
-    DimensionSelector dimSelector2 = new CardinalityAggregatorTest.TestDimensionSelector(values2, null);
+    DimensionSelector dimSelector2 = new CardinalityAggregatorTest.TestDimensionSelector(VALUES2, null);
 
-    StringBloomFilterAggregator agg1 = new StringBloomFilterAggregator(dimSelector1, maxNumValues, true);
+    StringBloomFilterAggregator agg1 = new StringBloomFilterAggregator(dimSelector1, MAX_NUM_VALUES, true);
-    StringBloomFilterAggregator agg2 = new StringBloomFilterAggregator(dimSelector2, maxNumValues, true);
+    StringBloomFilterAggregator agg2 = new StringBloomFilterAggregator(dimSelector2, MAX_NUM_VALUES, true);
 
-    for (int i = 0; i < values1.size(); ++i) {
+    for (int i = 0; i < VALUES1.size(); ++i) {
       aggregateDimension(Collections.singletonList(dimSelector1), agg1);
     }
-    for (int i = 0; i < values2.size(); ++i) {
+    for (int i = 0; i < VALUES2.size(); ++i) {
       aggregateDimension(Collections.singletonList(dimSelector2), agg2);
     }
 
@@ -435,7 +435,7 @@ public class BloomFilterAggregatorTest
         );
 
     BloomFilterMergeAggregator mergeAggregator =
-        new BloomFilterMergeAggregator(mergeDim, maxNumValues, true);
+        new BloomFilterMergeAggregator(mergeDim, MAX_NUM_VALUES, true);
 
     for (int i = 0; i < 2; ++i) {
       aggregateColumn(Collections.singletonList(mergeDim), mergeAggregator);
@@ -461,7 +461,7 @@ public class BloomFilterAggregatorTest
         );
 
     BloomFilterMergeAggregator mergeAggregator =
-        new BloomFilterMergeAggregator(mergeDim, maxNumValues, true);
+        new BloomFilterMergeAggregator(mergeDim, MAX_NUM_VALUES, true);
 
     for (int i = 0; i < 2; ++i) {
       aggregateColumn(Collections.singletonList(mergeDim), mergeAggregator);
@@ -486,7 +486,7 @@ public class BloomFilterAggregatorTest
             )
         );
 
-    BloomFilterMergeAggregator mergeAggregator = new BloomFilterMergeAggregator(mergeDim, maxNumValues, false);
+    BloomFilterMergeAggregator mergeAggregator = new BloomFilterMergeAggregator(mergeDim, MAX_NUM_VALUES, false);
 
     int maxSize = valueAggregatorFactory.getCombiningFactory().getMaxIntermediateSizeWithNulls();
     ByteBuffer buf = ByteBuffer.allocate(maxSize + 64);
@@ -513,7 +513,7 @@ public class BloomFilterAggregatorTest
     BloomFilterAggregatorFactory factory = new BloomFilterAggregatorFactory(
         "billy",
         new DefaultDimensionSpec("b", "b"),
-        maxNumValues
+        MAX_NUM_VALUES
     );
     ObjectMapper objectMapper = new DefaultObjectMapper();
     new BloomFilterExtensionModule().getJacksonModules().forEach(objectMapper::registerModule);
@@ -536,7 +536,7 @@ public class BloomFilterAggregatorTest
     BloomFilterAggregatorFactory factory2 = new BloomFilterAggregatorFactory(
         "billy",
         new ExtractionDimensionSpec("b", "b", new RegexDimExtractionFn(".*", false, null)),
-        maxNumValues
+        MAX_NUM_VALUES
     );
 
     Assert.assertEquals(
@@ -547,7 +547,7 @@ public class BloomFilterAggregatorTest
     BloomFilterAggregatorFactory factory3 = new BloomFilterAggregatorFactory(
         "billy",
         new RegexFilteredDimensionSpec(new DefaultDimensionSpec("a", "a"), ".*"),
-        maxNumValues
+        MAX_NUM_VALUES
     );
     Assert.assertEquals(
         factory3,

extensions-core/druid-bloom-filter/src/test/java/org/apache/druid/query/aggregation/bloom/BloomFilterGroupByQueryTest.java

@@ -53,13 +53,13 @@ import java.util.List;
 @RunWith(Parameterized.class)
 public class BloomFilterGroupByQueryTest
 {
-  private static final BloomFilterExtensionModule module = new BloomFilterExtensionModule();
+  private static final BloomFilterExtensionModule MODULE = new BloomFilterExtensionModule();
 
   static {
     // throwaway, just using to properly initialize jackson modules
     Guice.createInjector(
         binder -> binder.bind(Key.get(ObjectMapper.class, Json.class)).toInstance(TestHelper.makeJsonMapper()),
-        module
+        MODULE
     );
   }
 
@@ -72,7 +72,7 @@ public class BloomFilterGroupByQueryTest
   public BloomFilterGroupByQueryTest(final GroupByQueryConfig config)
   {
     helper = AggregationTestHelper.createGroupByQueryAggregationTestHelper(
-        Lists.newArrayList(module.getJacksonModules()),
+        Lists.newArrayList(MODULE.getJacksonModules()),
         config,
         tempFolder
     );

extensions-core/druid-bloom-filter/src/test/java/org/apache/druid/query/aggregation/bloom/sql/BloomFilterSqlAggregatorTest.java

@@ -96,7 +96,7 @@ public class BloomFilterSqlAggregatorTest
 {
   private static final int TEST_NUM_ENTRIES = 1000;
   private static AuthenticationResult authenticationResult = CalciteTests.REGULAR_USER_AUTH_RESULT;
-  private static final Injector injector = Guice.createInjector(
+  private static final Injector INJECTOR = Guice.createInjector(
       binder -> {
         binder.bind(Key.get(ObjectMapper.class, Json.class)).toInstance(TestHelper.makeJsonMapper());
         binder.bind(LookupExtractorFactoryContainerProvider.class).toInstance(
@@ -111,7 +111,7 @@ public class BloomFilterSqlAggregatorTest
   );
 
   private static ObjectMapper jsonMapper =
-      injector
+      INJECTOR
           .getInstance(Key.get(ObjectMapper.class, Json.class))
           .registerModules(Collections.singletonList(new BloomFilterSerializersModule()));
 

extensions-core/druid-bloom-filter/src/test/java/org/apache/druid/query/filter/sql/BloomDimFilterSqlTest.java

@@ -64,7 +64,7 @@ import java.util.Map;
 
 public class BloomDimFilterSqlTest extends BaseCalciteQueryTest
 {
-  private static final Injector injector = Guice.createInjector(
+  private static final Injector INJECTOR = Guice.createInjector(
       binder -> {
         binder.bind(Key.get(ObjectMapper.class, Json.class)).toInstance(TestHelper.makeJsonMapper());
         binder.bind(LookupExtractorFactoryContainerProvider.class).toInstance(
@@ -80,7 +80,7 @@ public class BloomDimFilterSqlTest extends BaseCalciteQueryTest
   );
 
   private static ObjectMapper jsonMapper =
-      injector
+      INJECTOR
           .getInstance(Key.get(ObjectMapper.class, Json.class))
           .registerModules(Collections.singletonList(new BloomFilterSerializersModule()));
 
@@ -88,10 +88,10 @@ public class BloomDimFilterSqlTest extends BaseCalciteQueryTest
   {
     final List<ExprMacroTable.ExprMacro> exprMacros = new ArrayList<>();
     for (Class<? extends ExprMacroTable.ExprMacro> clazz : ExpressionModule.EXPR_MACROS) {
-      exprMacros.add(injector.getInstance(clazz));
+      exprMacros.add(INJECTOR.getInstance(clazz));
     }
-    exprMacros.add(injector.getInstance(BloomFilterExprMacro.class));
+    exprMacros.add(INJECTOR.getInstance(BloomFilterExprMacro.class));
-    exprMacros.add(injector.getInstance(LookupExprMacro.class));
+    exprMacros.add(INJECTOR.getInstance(LookupExprMacro.class));
     return new ExprMacroTable(exprMacros);
   }
 
@@ -278,7 +278,7 @@ public class BloomDimFilterSqlTest extends BaseCalciteQueryTest
   {
     final DruidOperatorTable operatorTable = new DruidOperatorTable(
         ImmutableSet.of(),
-        ImmutableSet.of(injector.getInstance(BloomFilterOperatorConversion.class))
+        ImmutableSet.of(INJECTOR.getInstance(BloomFilterOperatorConversion.class))
     );
     return getResults(
         plannerConfig,

extensions-core/histogram/src/test/java/org/apache/druid/query/aggregation/histogram/ApproximateHistogramGroupByQueryTest.java

@@ -52,7 +52,7 @@ import java.util.List;
 @RunWith(Parameterized.class)
 public class ApproximateHistogramGroupByQueryTest
 {
-  private static final Closer resourceCloser = Closer.create();
+  private static final Closer RESOURCE_CLOSER = Closer.create();
 
   private final QueryRunner<Row> runner;
   private final GroupByQueryRunnerFactory factory;
@@ -124,7 +124,7 @@ public class ApproximateHistogramGroupByQueryTest
           config
       );
       final GroupByQueryRunnerFactory factory = factoryAndCloser.lhs;
-      resourceCloser.register(factoryAndCloser.rhs);
+      RESOURCE_CLOSER.register(factoryAndCloser.rhs);
       for (QueryRunner<ResultRow> runner : QueryRunnerTestHelper.makeQueryRunners(factory)) {
         final String testName = StringUtils.format(
             "config=%s, runner=%s",
@@ -152,7 +152,7 @@ public class ApproximateHistogramGroupByQueryTest
   @After
   public void teardown() throws IOException
   {
-    resourceCloser.close();
+    RESOURCE_CLOSER.close();
   }
 
   @Test
@@ -169,18 +169,18 @@ public class ApproximateHistogramGroupByQueryTest
     );
 
     GroupByQuery query = new GroupByQuery.Builder()
-        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setDataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .setGranularity(QueryRunnerTestHelper.allGran).setDimensions(new DefaultDimensionSpec(
+        .setGranularity(QueryRunnerTestHelper.ALL_GRAN).setDimensions(new DefaultDimensionSpec(
-            QueryRunnerTestHelper.marketDimension,
+            QueryRunnerTestHelper.MARKET_DIMENSION,
             "marketalias"
         ))
-        .setInterval(QueryRunnerTestHelper.fullOnIntervalSpec)
+        .setInterval(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
         .setLimitSpec(
             new DefaultLimitSpec(
                 Collections.singletonList(new OrderByColumnSpec("marketalias", OrderByColumnSpec.Direction.DESCENDING)),
                 1
             )
-        ).setAggregatorSpecs(QueryRunnerTestHelper.rowsCount, aggFactory)
+        ).setAggregatorSpecs(QueryRunnerTestHelper.ROWS_COUNT, aggFactory)
         .setPostAggregatorSpecs(
             Collections.singletonList(
                 new QuantilePostAggregator("quantile", "apphisto", 0.5f)
@@ -230,18 +230,18 @@ public class ApproximateHistogramGroupByQueryTest
     );
 
     GroupByQuery query = new GroupByQuery.Builder()
-        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setDataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .setGranularity(QueryRunnerTestHelper.allGran).setDimensions(new DefaultDimensionSpec(
+        .setGranularity(QueryRunnerTestHelper.ALL_GRAN).setDimensions(new DefaultDimensionSpec(
-            QueryRunnerTestHelper.marketDimension,
+            QueryRunnerTestHelper.MARKET_DIMENSION,
             "marketalias"
         ))
-        .setInterval(QueryRunnerTestHelper.fullOnIntervalSpec)
+        .setInterval(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
         .setLimitSpec(
             new DefaultLimitSpec(
                 Collections.singletonList(new OrderByColumnSpec("marketalias", OrderByColumnSpec.Direction.DESCENDING)),
                 1
             )
-        ).setAggregatorSpecs(QueryRunnerTestHelper.rowsCount, aggFactory)
+        ).setAggregatorSpecs(QueryRunnerTestHelper.ROWS_COUNT, aggFactory)
         .setPostAggregatorSpecs(
             Collections.singletonList(
                 new QuantilePostAggregator("quantile", "quantile", 0.5f)

extensions-core/histogram/src/test/java/org/apache/druid/query/aggregation/histogram/ApproximateHistogramTopNQueryTest.java

@@ -54,12 +54,12 @@ import java.util.Map;
 @RunWith(Parameterized.class)
 public class ApproximateHistogramTopNQueryTest
 {
-  private static final Closer resourceCloser = Closer.create();
+  private static final Closer RESOURCE_CLOSER = Closer.create();
 
   @AfterClass
   public static void teardown() throws IOException
   {
-    resourceCloser.close();
+    RESOURCE_CLOSER.close();
   }
 
   @Parameterized.Parameters(name = "{0}")
@@ -70,8 +70,8 @@ public class ApproximateHistogramTopNQueryTest
         "TopNQueryRunnerFactory-bufferPool",
         () -> ByteBuffer.allocate(2000)
     );
-    resourceCloser.register(defaultPool);
+    RESOURCE_CLOSER.register(defaultPool);
-    resourceCloser.register(customPool);
+    RESOURCE_CLOSER.register(customPool);
 
     return QueryRunnerTestHelper.transformToConstructionFeeder(
         Iterables.concat(
@@ -122,16 +122,16 @@ public class ApproximateHistogramTopNQueryTest
     );
 
     TopNQuery query = new TopNQueryBuilder()
-        .dataSource(QueryRunnerTestHelper.dataSource)
+        .dataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .granularity(QueryRunnerTestHelper.allGran)
+        .granularity(QueryRunnerTestHelper.ALL_GRAN)
-        .dimension(QueryRunnerTestHelper.marketDimension)
+        .dimension(QueryRunnerTestHelper.MARKET_DIMENSION)
         .metric(QueryRunnerTestHelper.dependentPostAggMetric)
         .threshold(4)
-        .intervals(QueryRunnerTestHelper.fullOnIntervalSpec)
+        .intervals(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
         .aggregators(
             Lists.newArrayList(
                 Iterables.concat(
-                    QueryRunnerTestHelper.commonDoubleAggregators,
+                    QueryRunnerTestHelper.COMMON_DOUBLE_AGGREGATORS,
                     Lists.newArrayList(
                         new DoubleMaxAggregatorFactory("maxIndex", "index"),
                         new DoubleMinAggregatorFactory("minIndex", "index"),
@@ -141,8 +141,8 @@ public class ApproximateHistogramTopNQueryTest
             )
         )
         .postAggregators(
-            QueryRunnerTestHelper.addRowsIndexConstant,
+            QueryRunnerTestHelper.ADD_ROWS_INDEX_CONSTANT,
-            QueryRunnerTestHelper.dependentPostAgg,
+            QueryRunnerTestHelper.DEPENDENT_POST_AGG,
             new QuantilePostAggregator("quantile", "apphisto", 0.5f)
         )
         .build();
@@ -153,7 +153,7 @@ public class ApproximateHistogramTopNQueryTest
             new TopNResultValue(
                 Arrays.<Map<String, Object>>asList(
                     ImmutableMap.<String, Object>builder()
-                        .put(QueryRunnerTestHelper.marketDimension, "total_market")
+                        .put(QueryRunnerTestHelper.MARKET_DIMENSION, "total_market")
                         .put("rows", 186L)
                         .put("index", 215679.82879638672D)
                         .put("addRowsIndexConstant", 215866.82879638672D)
@@ -184,7 +184,7 @@ public class ApproximateHistogramTopNQueryTest
                         )
                         .build(),
                     ImmutableMap.<String, Object>builder()
-                        .put(QueryRunnerTestHelper.marketDimension, "upfront")
+                        .put(QueryRunnerTestHelper.MARKET_DIMENSION, "upfront")
                         .put("rows", 186L)
                         .put("index", 192046.1060180664D)
                         .put("addRowsIndexConstant", 192233.1060180664D)
@@ -215,7 +215,7 @@ public class ApproximateHistogramTopNQueryTest
                         )
                         .build(),
                     ImmutableMap.<String, Object>builder()
-                        .put(QueryRunnerTestHelper.marketDimension, "spot")
+                        .put(QueryRunnerTestHelper.MARKET_DIMENSION, "spot")
                         .put("rows", 837L)
                         .put("index", 95606.57232284546D)
                         .put("addRowsIndexConstant", 96444.57232284546D)

extensions-core/histogram/src/test/java/org/apache/druid/query/aggregation/histogram/FixedBucketsHistogramGroupByQueryTest.java

@@ -52,7 +52,7 @@ import java.util.List;
 @RunWith(Parameterized.class)
 public class FixedBucketsHistogramGroupByQueryTest
 {
-  private static final Closer resourceCloser = Closer.create();
+  private static final Closer RESOURCE_CLOSER = Closer.create();
 
   private final QueryRunner<Row> runner;
   private final GroupByQueryRunnerFactory factory;
@@ -124,7 +124,7 @@ public class FixedBucketsHistogramGroupByQueryTest
           config
       );
       final GroupByQueryRunnerFactory factory = factoryAndCloser.lhs;
-      resourceCloser.register(factoryAndCloser.rhs);
+      RESOURCE_CLOSER.register(factoryAndCloser.rhs);
       for (QueryRunner<ResultRow> runner : QueryRunnerTestHelper.makeQueryRunners(factory)) {
         final String testName = StringUtils.format(
             "config=%s, runner=%s",
@@ -153,7 +153,7 @@ public class FixedBucketsHistogramGroupByQueryTest
   @After
   public void teardown() throws IOException
   {
-    resourceCloser.close();
+    RESOURCE_CLOSER.close();
   }
 
   @Test
@@ -170,18 +170,18 @@ public class FixedBucketsHistogramGroupByQueryTest
     );
 
     GroupByQuery query = new GroupByQuery.Builder()
-        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setDataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .setGranularity(QueryRunnerTestHelper.allGran).setDimensions(new DefaultDimensionSpec(
+        .setGranularity(QueryRunnerTestHelper.ALL_GRAN).setDimensions(new DefaultDimensionSpec(
-            QueryRunnerTestHelper.marketDimension,
+            QueryRunnerTestHelper.MARKET_DIMENSION,
             "marketalias"
         ))
-        .setInterval(QueryRunnerTestHelper.fullOnInterval)
+        .setInterval(QueryRunnerTestHelper.FULL_ON_INTERVAL)
         .setLimitSpec(
             new DefaultLimitSpec(
                 Collections.singletonList(new OrderByColumnSpec("marketalias", OrderByColumnSpec.Direction.DESCENDING)),
                 1
             )
-        ).setAggregatorSpecs(QueryRunnerTestHelper.rowsCount, aggFactory)
+        ).setAggregatorSpecs(QueryRunnerTestHelper.ROWS_COUNT, aggFactory)
         .setPostAggregatorSpecs(
             Collections.singletonList(
                 new QuantilePostAggregator("quantile", "histo", 0.5f)
@@ -231,18 +231,18 @@ public class FixedBucketsHistogramGroupByQueryTest
     );
 
     GroupByQuery query = new GroupByQuery.Builder()
-        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setDataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .setGranularity(QueryRunnerTestHelper.allGran).setDimensions(new DefaultDimensionSpec(
+        .setGranularity(QueryRunnerTestHelper.ALL_GRAN).setDimensions(new DefaultDimensionSpec(
-            QueryRunnerTestHelper.marketDimension,
+            QueryRunnerTestHelper.MARKET_DIMENSION,
             "marketalias"
         ))
-        .setInterval(QueryRunnerTestHelper.fullOnInterval)
+        .setInterval(QueryRunnerTestHelper.FULL_ON_INTERVAL)
         .setLimitSpec(
             new DefaultLimitSpec(
                 Collections.singletonList(new OrderByColumnSpec("marketalias", OrderByColumnSpec.Direction.DESCENDING)),
                 1
             )
-        ).setAggregatorSpecs(QueryRunnerTestHelper.rowsCount, aggFactory)
+        ).setAggregatorSpecs(QueryRunnerTestHelper.ROWS_COUNT, aggFactory)
         .setPostAggregatorSpecs(
             Collections.singletonList(
                 new QuantilePostAggregator("quantile", "quantile", 0.5f)

extensions-core/histogram/src/test/java/org/apache/druid/query/aggregation/histogram/FixedBucketsHistogramTopNQueryTest.java

@@ -54,12 +54,12 @@ import java.util.Map;
 @RunWith(Parameterized.class)
 public class FixedBucketsHistogramTopNQueryTest
 {
-  private static final Closer resourceCloser = Closer.create();
+  private static final Closer RESOURCE_CLOSER = Closer.create();
 
   @AfterClass
   public static void teardown() throws IOException
   {
-    resourceCloser.close();
+    RESOURCE_CLOSER.close();
   }
 
   @Parameterized.Parameters(name = "{0}")
@@ -70,8 +70,8 @@ public class FixedBucketsHistogramTopNQueryTest
         "TopNQueryRunnerFactory-bufferPool",
         () -> ByteBuffer.allocate(2000)
     );
-    resourceCloser.register(defaultPool);
+    RESOURCE_CLOSER.register(defaultPool);
-    resourceCloser.register(customPool);
+    RESOURCE_CLOSER.register(customPool);
 
     return QueryRunnerTestHelper.transformToConstructionFeeder(
         Iterables.concat(
@@ -122,16 +122,16 @@ public class FixedBucketsHistogramTopNQueryTest
     );
 
     TopNQuery query = new TopNQueryBuilder()
-        .dataSource(QueryRunnerTestHelper.dataSource)
+        .dataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .granularity(QueryRunnerTestHelper.allGran)
+        .granularity(QueryRunnerTestHelper.ALL_GRAN)
-        .dimension(QueryRunnerTestHelper.marketDimension)
+        .dimension(QueryRunnerTestHelper.MARKET_DIMENSION)
         .metric(QueryRunnerTestHelper.dependentPostAggMetric)
         .threshold(4)
-        .intervals(QueryRunnerTestHelper.fullOnIntervalSpec)
+        .intervals(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
         .aggregators(
             Lists.newArrayList(
                 Iterables.concat(
-                    QueryRunnerTestHelper.commonDoubleAggregators,
+                    QueryRunnerTestHelper.COMMON_DOUBLE_AGGREGATORS,
                     Lists.newArrayList(
                         new DoubleMaxAggregatorFactory("maxIndex", "index"),
                         new DoubleMinAggregatorFactory("minIndex", "index"),
@@ -141,8 +141,8 @@ public class FixedBucketsHistogramTopNQueryTest
             )
         )
         .postAggregators(
-            QueryRunnerTestHelper.addRowsIndexConstant,
+            QueryRunnerTestHelper.ADD_ROWS_INDEX_CONSTANT,
-            QueryRunnerTestHelper.dependentPostAgg,
+            QueryRunnerTestHelper.DEPENDENT_POST_AGG,
             new QuantilePostAggregator("quantile", "histo", 0.5f)
         )
         .build();
@@ -153,7 +153,7 @@ public class FixedBucketsHistogramTopNQueryTest
             new TopNResultValue(
                 Arrays.<Map<String, Object>>asList(
                     ImmutableMap.<String, Object>builder()
-                        .put(QueryRunnerTestHelper.marketDimension, "total_market")
+                        .put(QueryRunnerTestHelper.MARKET_DIMENSION, "total_market")
                         .put("rows", 186L)
                         .put("index", 215679.82879638672D)
                         .put("addRowsIndexConstant", 215866.82879638672D)
@@ -180,7 +180,7 @@ public class FixedBucketsHistogramTopNQueryTest
                         )
                         .build(),
                     ImmutableMap.<String, Object>builder()
-                        .put(QueryRunnerTestHelper.marketDimension, "upfront")
+                        .put(QueryRunnerTestHelper.MARKET_DIMENSION, "upfront")
                         .put("rows", 186L)
                         .put("index", 192046.1060180664D)
                         .put("addRowsIndexConstant", 192233.1060180664D)
@@ -207,7 +207,7 @@ public class FixedBucketsHistogramTopNQueryTest
                         )
                         .build(),
                     ImmutableMap.<String, Object>builder()
-                        .put(QueryRunnerTestHelper.marketDimension, "spot")
+                        .put(QueryRunnerTestHelper.MARKET_DIMENSION, "spot")
                         .put("rows", 837L)
                         .put("index", 95606.57232284546D)
                         .put("addRowsIndexConstant", 96444.57232284546D)

extensions-core/kafka-extraction-namespace/src/test/java/org/apache/druid/query/lookup/TestKafkaExtractionCluster.java

@@ -64,8 +64,8 @@ import java.util.concurrent.ThreadLocalRandom;
 public class TestKafkaExtractionCluster
 {
   private static final Logger log = new Logger(TestKafkaExtractionCluster.class);
-  private static final String topicName = "testTopic";
+  private static final String TOPIC_NAME = "testTopic";
-  private static final Map<String, String> kafkaProperties = new HashMap<>();
+  private static final Map<String, String> KAFKA_PROPERTIES = new HashMap<>();
 
   @Rule
   public TemporaryFolder temporaryFolder = new TemporaryFolder();
@@ -81,7 +81,7 @@ public class TestKafkaExtractionCluster
   private static List<ProducerRecord<byte[], byte[]>> generateRecords()
   {
     return ImmutableList.of(
-            new ProducerRecord<>(topicName, 0,
+            new ProducerRecord<>(TOPIC_NAME, 0,
                     StringUtils.toUtf8("abcdefg"),
                     StringUtils.toUtf8("abcdefg")));
   }
@@ -131,7 +131,7 @@ public class TestKafkaExtractionCluster
 
     final KafkaLookupExtractorFactory kafkaLookupExtractorFactory = new KafkaLookupExtractorFactory(
         null,
-        topicName,
+        TOPIC_NAME,
         consumerProperties
     );
 
@@ -149,7 +149,7 @@ public class TestKafkaExtractionCluster
   @Nonnull
   private Map<String, String> getConsumerProperties()
   {
-    final Map<String, String> props = new HashMap<>(kafkaProperties);
+    final Map<String, String> props = new HashMap<>(KAFKA_PROPERTIES);
     int port = kafkaServer.socketServer().config().port();
     props.put("bootstrap.servers", StringUtils.format("127.0.0.1:%d", port));
     return props;
@@ -168,7 +168,7 @@ public class TestKafkaExtractionCluster
   private KafkaConfig getBrokerProperties() throws IOException
   {
     final Properties serverProperties = new Properties();
-    serverProperties.putAll(kafkaProperties);
+    serverProperties.putAll(KAFKA_PROPERTIES);
     serverProperties.put("broker.id", "0");
     serverProperties.put("zookeeper.connect", zkServer.getConnectString());
     serverProperties.put("port", String.valueOf(ThreadLocalRandom.current().nextInt(9999) + 10000));
@@ -193,13 +193,13 @@ public class TestKafkaExtractionCluster
   private Properties makeProducerProperties()
   {
     final Properties kafkaProducerProperties = new Properties();
-    kafkaProducerProperties.putAll(kafkaProperties);
+    kafkaProducerProperties.putAll(KAFKA_PROPERTIES);
     int port = kafkaServer.socketServer().config().port();
     kafkaProducerProperties.put("bootstrap.servers", StringUtils.format("127.0.0.1:%d", port));
     kafkaProducerProperties.put("key.serializer", ByteArraySerializer.class.getName());
     kafkaProducerProperties.put("value.serializer", ByteArraySerializer.class.getName());
     kafkaProducerProperties.put("acks", "all");
-    kafkaProperties.put("request.required.acks", "1");
+    KAFKA_PROPERTIES.put("request.required.acks", "1");
     return kafkaProducerProperties;
   }
 
@@ -222,7 +222,7 @@ public class TestKafkaExtractionCluster
       long events = factory.getCompletedEventCount();
 
       log.info("-------------------------     Sending foo bar     -------------------------------");
-      producer.send(new ProducerRecord<>(topicName, StringUtils.toUtf8("foo"), StringUtils.toUtf8("bar")));
+      producer.send(new ProducerRecord<>(TOPIC_NAME, StringUtils.toUtf8("foo"), StringUtils.toUtf8("bar")));
 
       long start = System.currentTimeMillis();
       while (events == factory.getCompletedEventCount()) {
@@ -241,7 +241,7 @@ public class TestKafkaExtractionCluster
       events = factory.getCompletedEventCount();
 
       log.info("-------------------------     Sending baz bat     -------------------------------");
-      producer.send(new ProducerRecord<>(topicName, StringUtils.toUtf8("baz"), StringUtils.toUtf8("bat")));
+      producer.send(new ProducerRecord<>(TOPIC_NAME, StringUtils.toUtf8("baz"), StringUtils.toUtf8("bat")));
       while (events == factory.getCompletedEventCount()) {
         Thread.sleep(10);
         if (System.currentTimeMillis() > start + 60_000) {

extensions-core/kafka-indexing-service/src/test/java/org/apache/druid/indexing/kafka/KafkaIndexTaskClientTest.java

@@ -72,7 +72,7 @@ public class KafkaIndexTaskClientTest extends EasyMockSupport
   @Rule
   public ExpectedException expectedException = ExpectedException.none();
 
-  private static final ObjectMapper objectMapper = new DefaultObjectMapper();
+  private static final ObjectMapper OBJECT_MAPPER = new DefaultObjectMapper();
   private static final String TEST_ID = "test-id";
   private static final List<String> TEST_IDS = Arrays.asList("test-id1", "test-id2", "test-id3", "test-id4");
   private static final String TEST_HOST = "test-host";
@@ -111,7 +111,7 @@ public class KafkaIndexTaskClientTest extends EasyMockSupport
     response = createMock(HttpResponse.class);
     headers = createMock(HttpHeaders.class);
 
-    client = new TestableKafkaIndexTaskClient(httpClient, objectMapper, taskInfoProvider);
+    client = new TestableKafkaIndexTaskClient(httpClient, OBJECT_MAPPER, taskInfoProvider);
     EasyMock.expect(taskInfoProvider.getTaskLocation(TEST_ID))
             .andReturn(new TaskLocation(TEST_HOST, TEST_PORT, TEST_TLS_PORT))
             .anyTimes();
@@ -285,7 +285,7 @@ public class KafkaIndexTaskClientTest extends EasyMockSupport
   @Test
   public void testGetCurrentOffsetsWithRetry() throws Exception
   {
-    client = new TestableKafkaIndexTaskClient(httpClient, objectMapper, taskInfoProvider, 3);
+    client = new TestableKafkaIndexTaskClient(httpClient, OBJECT_MAPPER, taskInfoProvider, 3);
 
     Capture<Request> captured = Capture.newInstance(CaptureType.ALL);
     EasyMock.expect(responseHolder.getStatus()).andReturn(HttpResponseStatus.NOT_FOUND).times(6)
@@ -330,7 +330,7 @@ public class KafkaIndexTaskClientTest extends EasyMockSupport
     expectedException.expect(RuntimeException.class);
     expectedException.expectMessage("org.apache.druid.java.util.common.IOE: Received status [404]");
 
-    client = new TestableKafkaIndexTaskClient(httpClient, objectMapper, taskInfoProvider, 2);
+    client = new TestableKafkaIndexTaskClient(httpClient, OBJECT_MAPPER, taskInfoProvider, 2);
 
     EasyMock.expect(responseHolder.getStatus()).andReturn(HttpResponseStatus.NOT_FOUND).anyTimes();
     EasyMock.expect(responseHolder.getContent()).andReturn("").anyTimes();
@@ -385,7 +385,7 @@ public class KafkaIndexTaskClientTest extends EasyMockSupport
   @Test
   public void testGetStartTime() throws Exception
   {
-    client = new TestableKafkaIndexTaskClient(httpClient, objectMapper, taskInfoProvider, 2);
+    client = new TestableKafkaIndexTaskClient(httpClient, OBJECT_MAPPER, taskInfoProvider, 2);
     DateTime now = DateTimes.nowUtc();
 
     Capture<Request> captured = Capture.newInstance();

extensions-core/kafka-indexing-service/src/test/java/org/apache/druid/indexing/kafka/KafkaRecordSupplierTest.java

@@ -54,7 +54,7 @@ public class KafkaRecordSupplierTest
   private static long poll_timeout_millis = 1000;
   private static int pollRetry = 5;
   private static int topicPosFix = 0;
-  private static final ObjectMapper objectMapper = TestHelper.makeJsonMapper();
+  private static final ObjectMapper OBJECT_MAPPER = TestHelper.makeJsonMapper();
 
   private static TestingCluster zkServer;
   private static TestBroker kafkaServer;
@@ -194,7 +194,7 @@ public class KafkaRecordSupplierTest
     );
 
     KafkaRecordSupplier recordSupplier = new KafkaRecordSupplier(
-        kafkaServer.consumerProperties(), objectMapper);
+        kafkaServer.consumerProperties(), OBJECT_MAPPER);
 
     Assert.assertTrue(recordSupplier.getAssignment().isEmpty());
 
@@ -224,7 +224,7 @@ public class KafkaRecordSupplierTest
 
     KafkaRecordSupplier recordSupplier = new KafkaRecordSupplier(
         properties,
-        objectMapper
+        OBJECT_MAPPER
     );
 
     Assert.assertTrue(recordSupplier.getAssignment().isEmpty());
@@ -255,7 +255,7 @@ public class KafkaRecordSupplierTest
 
     KafkaRecordSupplier recordSupplier = new KafkaRecordSupplier(
         properties,
-        objectMapper
+        OBJECT_MAPPER
     );
 
     recordSupplier.assign(partitions);
@@ -289,7 +289,7 @@ public class KafkaRecordSupplierTest
     );
 
     KafkaRecordSupplier recordSupplier = new KafkaRecordSupplier(
-        kafkaServer.consumerProperties(), objectMapper);
+        kafkaServer.consumerProperties(), OBJECT_MAPPER);
 
     recordSupplier.assign(partitions);
     recordSupplier.seekToEarliest(partitions);
@@ -330,7 +330,7 @@ public class KafkaRecordSupplierTest
 
 
     KafkaRecordSupplier recordSupplier = new KafkaRecordSupplier(
-        kafkaServer.consumerProperties(), objectMapper);
+        kafkaServer.consumerProperties(), OBJECT_MAPPER);
 
     recordSupplier.assign(partitions);
     recordSupplier.seekToEarliest(partitions);
@@ -401,7 +401,7 @@ public class KafkaRecordSupplierTest
     );
 
     KafkaRecordSupplier recordSupplier = new KafkaRecordSupplier(
-        kafkaServer.consumerProperties(), objectMapper);
+        kafkaServer.consumerProperties(), OBJECT_MAPPER);
 
     recordSupplier.assign(partitions);
     recordSupplier.seekToEarliest(partitions);
@@ -444,7 +444,7 @@ public class KafkaRecordSupplierTest
     );
 
     KafkaRecordSupplier recordSupplier = new KafkaRecordSupplier(
-        kafkaServer.consumerProperties(), objectMapper);
+        kafkaServer.consumerProperties(), OBJECT_MAPPER);
 
     recordSupplier.assign(partitions);
     recordSupplier.seekToEarliest(partitions);
@@ -477,7 +477,7 @@ public class KafkaRecordSupplierTest
     );
 
     KafkaRecordSupplier recordSupplier = new KafkaRecordSupplier(
-        kafkaServer.consumerProperties(), objectMapper);
+        kafkaServer.consumerProperties(), OBJECT_MAPPER);
 
     recordSupplier.assign(partitions);
 
@@ -503,7 +503,7 @@ public class KafkaRecordSupplierTest
     );
 
     KafkaRecordSupplier recordSupplier = new KafkaRecordSupplier(
-        kafkaServer.consumerProperties(), objectMapper);
+        kafkaServer.consumerProperties(), OBJECT_MAPPER);
 
     recordSupplier.assign(partitions);
     recordSupplier.seekToEarliest(partitions);

extensions-core/kafka-indexing-service/src/test/java/org/apache/druid/indexing/kafka/KafkaSamplerSpecTest.java

@@ -62,11 +62,11 @@ import java.util.Map;
 
 public class KafkaSamplerSpecTest
 {
-  private static final ObjectMapper objectMapper = TestHelper.makeJsonMapper();
+  private static final ObjectMapper OBJECT_MAPPER = TestHelper.makeJsonMapper();
   private static final String TOPIC = "sampling";
   private static final DataSchema DATA_SCHEMA = new DataSchema(
       "test_ds",
-      objectMapper.convertValue(
+      OBJECT_MAPPER.convertValue(
           new StringInputRowParser(
               new JSONParseSpec(
                   new TimestampSpec("timestamp", "iso", null),
@@ -94,7 +94,7 @@ public class KafkaSamplerSpecTest
       },
       new UniformGranularitySpec(Granularities.DAY, Granularities.NONE, null),
       null,
-      objectMapper
+      OBJECT_MAPPER
   );
 
   private static TestingCluster zkServer;
@@ -167,8 +167,8 @@ public class KafkaSamplerSpecTest
     KafkaSamplerSpec samplerSpec = new KafkaSamplerSpec(
         supervisorSpec,
         new SamplerConfig(5, null, null, null),
-        new FirehoseSampler(objectMapper, new SamplerCache(MapCache.create(100000))),
+        new FirehoseSampler(OBJECT_MAPPER, new SamplerCache(MapCache.create(100000))),
-        objectMapper
+        OBJECT_MAPPER
     );
 
     SamplerResponse response = samplerSpec.sample();

extensions-core/kafka-indexing-service/src/test/java/org/apache/druid/indexing/kafka/supervisor/KafkaSupervisorTest.java

@@ -122,7 +122,7 @@ import java.util.concurrent.Executor;
 @RunWith(Parameterized.class)
 public class KafkaSupervisorTest extends EasyMockSupport
 {
-  private static final ObjectMapper objectMapper = TestHelper.makeJsonMapper();
+  private static final ObjectMapper OBJECT_MAPPER = TestHelper.makeJsonMapper();
   private static final String TOPIC_PREFIX = "testTopic";
   private static final String DATASOURCE = "testDS";
   private static final int NUM_PARTITIONS = 3;
@@ -237,7 +237,7 @@ public class KafkaSupervisorTest extends EasyMockSupport
     final Map<String, Object> contexts = supervisor.createIndexTasks(
         1,
         "seq",
-        objectMapper,
+        OBJECT_MAPPER,
         new TreeMap<>(),
         new KafkaIndexTaskIOConfig(
             0,
@@ -3393,7 +3393,7 @@ public class KafkaSupervisorTest extends EasyMockSupport
         taskMaster,
         indexerMetadataStorageCoordinator,
         taskClientFactory,
-        objectMapper,
+        OBJECT_MAPPER,
         new KafkaSupervisorSpec(
             dataSchema,
             tuningConfig,
@@ -3404,7 +3404,7 @@ public class KafkaSupervisorTest extends EasyMockSupport
             taskMaster,
             indexerMetadataStorageCoordinator,
             taskClientFactory,
-            objectMapper,
+            OBJECT_MAPPER,
             new NoopServiceEmitter(),
             new DruidMonitorSchedulerConfig(),
             rowIngestionMetersFactory,
@@ -3500,7 +3500,7 @@ public class KafkaSupervisorTest extends EasyMockSupport
         taskMaster,
         indexerMetadataStorageCoordinator,
         taskClientFactory,
-        objectMapper,
+        OBJECT_MAPPER,
         new KafkaSupervisorSpec(
             dataSchema,
             tuningConfig,
@@ -3511,7 +3511,7 @@ public class KafkaSupervisorTest extends EasyMockSupport
             taskMaster,
             indexerMetadataStorageCoordinator,
             taskClientFactory,
-            objectMapper,
+            OBJECT_MAPPER,
             new NoopServiceEmitter(),
             new DruidMonitorSchedulerConfig(),
             rowIngestionMetersFactory,
@@ -3584,7 +3584,7 @@ public class KafkaSupervisorTest extends EasyMockSupport
         taskMaster,
         indexerMetadataStorageCoordinator,
         taskClientFactory,
-        objectMapper,
+        OBJECT_MAPPER,
         new KafkaSupervisorSpec(
             dataSchema,
             tuningConfig,
@@ -3595,7 +3595,7 @@ public class KafkaSupervisorTest extends EasyMockSupport
             taskMaster,
             indexerMetadataStorageCoordinator,
             taskClientFactory,
-            objectMapper,
+            OBJECT_MAPPER,
             new NoopServiceEmitter(),
             new DruidMonitorSchedulerConfig(),
             rowIngestionMetersFactory,
@@ -3613,7 +3613,7 @@ public class KafkaSupervisorTest extends EasyMockSupport
 
     return new DataSchema(
         dataSource,
-        objectMapper.convertValue(
+        OBJECT_MAPPER.convertValue(
             new StringInputRowParser(
                 new JSONParseSpec(
                     new TimestampSpec("timestamp", "iso", null),
@@ -3636,7 +3636,7 @@ public class KafkaSupervisorTest extends EasyMockSupport
             ImmutableList.of()
         ),
         null,
-        objectMapper
+        OBJECT_MAPPER
     );
   }
 
@@ -3717,7 +3717,7 @@ public class KafkaSupervisorTest extends EasyMockSupport
         null,
         null,
         rowIngestionMetersFactory,
-        objectMapper,
+        OBJECT_MAPPER,
         new DummyForInjectionAppenderatorsManager()
     );
   }

extensions-core/kinesis-indexing-service/src/test/java/org/apache/druid/indexing/kinesis/KinesisIndexTaskClientTest.java

@@ -73,7 +73,7 @@ public class KinesisIndexTaskClientTest extends EasyMockSupport
   @Rule
   public ExpectedException expectedException = ExpectedException.none();
 
-  private static final ObjectMapper objectMapper = new DefaultObjectMapper();
+  private static final ObjectMapper OBJECT_MAPPER = new DefaultObjectMapper();
   private static final String TEST_ID = "test-id";
   private static final List<String> TEST_IDS = Arrays.asList("test-id1", "test-id2", "test-id3", "test-id4");
   private static final String TEST_HOST = "test-host";
@@ -112,7 +112,7 @@ public class KinesisIndexTaskClientTest extends EasyMockSupport
     response = createMock(HttpResponse.class);
     headers = createMock(HttpHeaders.class);
 
-    client = new TestableKinesisIndexTaskClient(httpClient, objectMapper, taskInfoProvider);
+    client = new TestableKinesisIndexTaskClient(httpClient, OBJECT_MAPPER, taskInfoProvider);
     EasyMock.expect(taskInfoProvider.getTaskLocation(TEST_ID))
             .andReturn(new TaskLocation(TEST_HOST, TEST_PORT, TEST_TLS_PORT))
             .anyTimes();
@@ -286,7 +286,7 @@ public class KinesisIndexTaskClientTest extends EasyMockSupport
   @Test
   public void testGetCurrentOffsetsWithRetry() throws Exception
   {
-    client = new TestableKinesisIndexTaskClient(httpClient, objectMapper, taskInfoProvider, 3);
+    client = new TestableKinesisIndexTaskClient(httpClient, OBJECT_MAPPER, taskInfoProvider, 3);
 
     Capture<Request> captured = Capture.newInstance(CaptureType.ALL);
     EasyMock.expect(responseHolder.getStatus()).andReturn(HttpResponseStatus.NOT_FOUND).times(6)
@@ -331,7 +331,7 @@ public class KinesisIndexTaskClientTest extends EasyMockSupport
     expectedException.expect(RuntimeException.class);
     expectedException.expectMessage("org.apache.druid.java.util.common.IOE: Received status [404]");
 
-    client = new TestableKinesisIndexTaskClient(httpClient, objectMapper, taskInfoProvider, 2);
+    client = new TestableKinesisIndexTaskClient(httpClient, OBJECT_MAPPER, taskInfoProvider, 2);
 
     EasyMock.expect(responseHolder.getStatus()).andReturn(HttpResponseStatus.NOT_FOUND).anyTimes();
     EasyMock.expect(responseHolder.getContent()).andReturn("").anyTimes();
@@ -386,7 +386,7 @@ public class KinesisIndexTaskClientTest extends EasyMockSupport
   @Test
   public void testGetStartTime() throws Exception
   {
-    client = new TestableKinesisIndexTaskClient(httpClient, objectMapper, taskInfoProvider, 2);
+    client = new TestableKinesisIndexTaskClient(httpClient, OBJECT_MAPPER, taskInfoProvider, 2);
     DateTime now = DateTimes.nowUtc();
 
     Capture<Request> captured = Capture.newInstance();

extensions-core/kinesis-indexing-service/src/test/java/org/apache/druid/indexing/kinesis/KinesisRecordSupplierTest.java

@@ -53,7 +53,7 @@ import java.util.stream.Collectors;
 
 public class KinesisRecordSupplierTest extends EasyMockSupport
 {
-  private static final String stream = "stream";
+  private static final String STREAM = "stream";
   private static final long POLL_TIMEOUT_MILLIS = 2000;
   private static final String SHARD_ID1 = "1";
   private static final String SHARD_ID0 = "0";
@@ -78,7 +78,7 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
   private static final List<Object> ALL_RECORDS = ImmutableList.builder()
                                                                .addAll(SHARD0_RECORDS.stream()
                                                                                      .map(x -> new OrderedPartitionableRecord<>(
-                                                                                         stream,
+                                                                                         STREAM,
                                                                                          SHARD_ID0,
                                                                                          x.getSequenceNumber(),
                                                                                          Collections
@@ -91,7 +91,7 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
                                                                                              .toList()))
                                                                .addAll(SHARD1_RECORDS.stream()
                                                                                      .map(x -> new OrderedPartitionableRecord<>(
-                                                                                         stream,
+                                                                                         STREAM,
                                                                                          SHARD_ID1,
                                                                                          x.getSequenceNumber(),
                                                                                          Collections
@@ -182,8 +182,8 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
     replayAll();
 
     Set<StreamPartition<String>> partitions = ImmutableSet.of(
-        StreamPartition.of(stream, SHARD_ID0),
+        StreamPartition.of(STREAM, SHARD_ID0),
-        StreamPartition.of(stream, SHARD_ID1)
+        StreamPartition.of(STREAM, SHARD_ID1)
     );
 
     recordSupplier = new KinesisRecordSupplier(
@@ -204,13 +204,13 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
     recordSupplier.assign(partitions);
 
     Assert.assertEquals(partitions, recordSupplier.getAssignment());
-    Assert.assertEquals(ImmutableSet.of(SHARD_ID1, SHARD_ID0), recordSupplier.getPartitionIds(stream));
+    Assert.assertEquals(ImmutableSet.of(SHARD_ID1, SHARD_ID0), recordSupplier.getPartitionIds(STREAM));
     Assert.assertEquals(Collections.emptyList(), recordSupplier.poll(100));
 
     verifyAll();
 
     final DescribeStreamRequest expectedRequest = new DescribeStreamRequest();
-    expectedRequest.setStreamName(stream);
+    expectedRequest.setStreamName(STREAM);
     expectedRequest.setExclusiveStartShardId("0");
     Assert.assertEquals(expectedRequest, capturedRequest.getValue());
   }
@@ -266,8 +266,8 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
     replayAll();
 
     Set<StreamPartition<String>> partitions = ImmutableSet.of(
-        StreamPartition.of(stream, SHARD_ID0),
+        StreamPartition.of(STREAM, SHARD_ID0),
-        StreamPartition.of(stream, SHARD_ID1)
+        StreamPartition.of(STREAM, SHARD_ID1)
     );
 
 
@@ -338,8 +338,8 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
 
     replayAll();
 
-    StreamPartition<String> shard0Partition = StreamPartition.of(stream, SHARD_ID0);
+    StreamPartition<String> shard0Partition = StreamPartition.of(STREAM, SHARD_ID0);
-    StreamPartition<String> shard1Partition = StreamPartition.of(stream, SHARD_ID1);
+    StreamPartition<String> shard1Partition = StreamPartition.of(STREAM, SHARD_ID1);
     Set<StreamPartition<String>> partitions = ImmutableSet.of(
         shard0Partition,
         shard1Partition
@@ -405,8 +405,8 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
 
     replayAll();
 
-    StreamPartition<String> shard0 = StreamPartition.of(stream, SHARD_ID0);
+    StreamPartition<String> shard0 = StreamPartition.of(STREAM, SHARD_ID0);
-    StreamPartition<String> shard1 = StreamPartition.of(stream, SHARD_ID1);
+    StreamPartition<String> shard1 = StreamPartition.of(STREAM, SHARD_ID1);
     Set<StreamPartition<String>> partitions = ImmutableSet.of(
         shard0,
         shard1
@@ -440,8 +440,8 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
   @Test(expected = ISE.class)
   public void testSeekUnassigned() throws InterruptedException
   {
-    StreamPartition<String> shard0 = StreamPartition.of(stream, SHARD_ID0);
+    StreamPartition<String> shard0 = StreamPartition.of(STREAM, SHARD_ID0);
-    StreamPartition<String> shard1 = StreamPartition.of(stream, SHARD_ID1);
+    StreamPartition<String> shard1 = StreamPartition.of(STREAM, SHARD_ID1);
     Set<StreamPartition<String>> partitions = ImmutableSet.of(
         shard1
     );
@@ -503,7 +503,7 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
     replayAll();
 
     Set<StreamPartition<String>> partitions = ImmutableSet.of(
-        StreamPartition.of(stream, SHARD_ID1)
+        StreamPartition.of(STREAM, SHARD_ID1)
     );
 
     recordSupplier = new KinesisRecordSupplier(
@@ -520,7 +520,7 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
     );
 
     recordSupplier.assign(partitions);
-    recordSupplier.seek(StreamPartition.of(stream, SHARD_ID1), "5");
+    recordSupplier.seek(StreamPartition.of(STREAM, SHARD_ID1), "5");
     recordSupplier.start();
 
     for (int i = 0; i < 10 && recordSupplier.bufferSize() < 6; i++) {
@@ -534,7 +534,7 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
         firstRecord
     );
 
-    recordSupplier.seek(StreamPartition.of(stream, SHARD_ID1), "7");
+    recordSupplier.seek(StreamPartition.of(STREAM, SHARD_ID1), "7");
     recordSupplier.start();
 
     while (recordSupplier.bufferSize() < 4) {
@@ -585,8 +585,8 @@ public class KinesisRecordSupplierTest extends EasyMockSupport
     replayAll();
 
     Set<StreamPartition<String>> partitions = ImmutableSet.of(
-        StreamPartition.of(stream, SHARD_ID0),
+        StreamPartition.of(STREAM, SHARD_ID0),
-        StreamPartition.of(stream, SHARD_ID1)
+        StreamPartition.of(STREAM, SHARD_ID1)
     );
 
 

extensions-core/kinesis-indexing-service/src/test/java/org/apache/druid/indexing/kinesis/KinesisSamplerSpecTest.java

@@ -66,12 +66,12 @@ import java.util.Map;
 
 public class KinesisSamplerSpecTest extends EasyMockSupport
 {
-  private static final ObjectMapper objectMapper = TestHelper.makeJsonMapper();
+  private static final ObjectMapper OBJECT_MAPPER = TestHelper.makeJsonMapper();
   private static final String STREAM = "sampling";
   private static final String SHARD_ID = "1";
   private static final DataSchema DATA_SCHEMA = new DataSchema(
       "test_ds",
-      objectMapper.convertValue(
+      OBJECT_MAPPER.convertValue(
           new StringInputRowParser(
               new JSONParseSpec(
                   new TimestampSpec("timestamp", "iso", null),
@@ -99,7 +99,7 @@ public class KinesisSamplerSpecTest extends EasyMockSupport
       },
       new UniformGranularitySpec(Granularities.DAY, Granularities.NONE, null),
       null,
-      objectMapper
+      OBJECT_MAPPER
   );
 
   private final KinesisRecordSupplier recordSupplier = mock(KinesisRecordSupplier.class);
@@ -183,7 +183,7 @@ public class KinesisSamplerSpecTest extends EasyMockSupport
     KinesisSamplerSpec samplerSpec = new TestableKinesisSamplerSpec(
         supervisorSpec,
         new SamplerConfig(5, null, null, null),
-        new FirehoseSampler(objectMapper, new SamplerCache(MapCache.create(100000))),
+        new FirehoseSampler(OBJECT_MAPPER, new SamplerCache(MapCache.create(100000))),
         null
     );
 

extensions-core/lookups-cached-global/src/test/java/org/apache/druid/server/lookup/namespace/NamespacedExtractorModuleTest.java

@@ -51,7 +51,7 @@ import java.util.Map;
  */
 public class NamespacedExtractorModuleTest
 {
-  private static final ObjectMapper mapper = UriExtractionNamespaceTest.registerTypes(new DefaultObjectMapper());
+  private static final ObjectMapper MAPPER = UriExtractionNamespaceTest.registerTypes(new DefaultObjectMapper());
   private CacheScheduler scheduler;
   private Lifecycle lifecycle;
 
@@ -93,7 +93,7 @@ public class NamespacedExtractorModuleTest
   {
     final File tmpFile = temporaryFolder.newFile();
     try (Writer out = Files.newWriter(tmpFile, StandardCharsets.UTF_8)) {
-      out.write(mapper.writeValueAsString(ImmutableMap.of("foo", "bar")));
+      out.write(MAPPER.writeValueAsString(ImmutableMap.of("foo", "bar")));
     }
     final UriCacheGenerator factory = new UriCacheGenerator(
         ImmutableMap.of("file", new LocalFileTimestampVersionFinder())
@@ -119,7 +119,7 @@ public class NamespacedExtractorModuleTest
   {
     final File tmpFile = temporaryFolder.newFile();
     try (Writer out = Files.newWriter(tmpFile, StandardCharsets.UTF_8)) {
-      out.write(mapper.writeValueAsString(ImmutableMap.of("foo", "bar")));
+      out.write(MAPPER.writeValueAsString(ImmutableMap.of("foo", "bar")));
     }
     final UriExtractionNamespace namespace = new UriExtractionNamespace(
         tmpFile.toURI(),
@@ -140,7 +140,7 @@ public class NamespacedExtractorModuleTest
   {
     final File tmpFile = temporaryFolder.newFile();
     try (Writer out = Files.newWriter(tmpFile, StandardCharsets.UTF_8)) {
-      out.write(mapper.writeValueAsString(ImmutableMap.of("foo", "bar")));
+      out.write(MAPPER.writeValueAsString(ImmutableMap.of("foo", "bar")));
     }
     final UriExtractionNamespace namespace = new UriExtractionNamespace(
         tmpFile.toURI(),
@@ -161,7 +161,7 @@ public class NamespacedExtractorModuleTest
   {
     final File tmpFile = temporaryFolder.newFile();
     try (Writer out = Files.newWriter(tmpFile, StandardCharsets.UTF_8)) {
-      out.write(mapper.writeValueAsString(ImmutableMap.of("foo", "bar")));
+      out.write(MAPPER.writeValueAsString(ImmutableMap.of("foo", "bar")));
     }
     final UriExtractionNamespace namespace = new UriExtractionNamespace(
         tmpFile.toURI(),

extensions-core/lookups-cached-global/src/test/java/org/apache/druid/server/lookup/namespace/cache/JdbcExtractionNamespaceTest.java

@@ -70,12 +70,12 @@ public class JdbcExtractionNamespaceTest
   @Rule
   public final TestDerbyConnector.DerbyConnectorRule derbyConnectorRule = new TestDerbyConnector.DerbyConnectorRule();
   private static final Logger log = new Logger(JdbcExtractionNamespaceTest.class);
-  private static final String tableName = "abstractDbRenameTest";
+  private static final String TABLE_NAME = "abstractDbRenameTest";
-  private static final String keyName = "keyName";
+  private static final String KEY_NAME = "keyName";
-  private static final String valName = "valName";
+  private static final String VAL_NAME = "valName";
-  private static final String tsColumn_ = "tsColumn";
+  private static final String TS_COLUMN = "tsColumn";
-  private static final String filterColumn = "filterColumn";
+  private static final String FILTER_COLUMN = "filterColumn";
-  private static final Map<String, String[]> renames = ImmutableMap.of(
+  private static final Map<String, String[]> RENAMES = ImmutableMap.of(
       "foo", new String[]{"bar", "1"},
       "bad", new String[]{"bar", "1"},
       "how about that", new String[]{"foo", "0"},
@@ -129,22 +129,22 @@ public class JdbcExtractionNamespaceTest
                 handle.createStatement(
                     StringUtils.format(
                         "CREATE TABLE %s (%s TIMESTAMP, %s VARCHAR(64), %s VARCHAR(64), %s VARCHAR(64))",
-                        tableName,
+                        TABLE_NAME,
-                        tsColumn_,
+                        TS_COLUMN,
-                        filterColumn,
+                        FILTER_COLUMN,
-                        keyName,
+                        KEY_NAME,
-                        valName
+                        VAL_NAME
                     )
                 ).setQueryTimeout(1).execute()
             );
-            handle.createStatement(StringUtils.format("TRUNCATE TABLE %s", tableName)).setQueryTimeout(1).execute();
+            handle.createStatement(StringUtils.format("TRUNCATE TABLE %s", TABLE_NAME)).setQueryTimeout(1).execute();
             handle.commit();
             closer.register(new Closeable()
             {
               @Override
               public void close() throws IOException
               {
-                handle.createStatement("DROP TABLE " + tableName).setQueryTimeout(1).execute();
+                handle.createStatement("DROP TABLE " + TABLE_NAME).setQueryTimeout(1).execute();
                 final ListenableFuture future = setupTeardownService.submit(new Runnable()
                 {
                   @Override
@@ -179,7 +179,7 @@ public class JdbcExtractionNamespaceTest
                 Assert.assertEquals(0, scheduler.getActiveEntries());
               }
             });
-            for (Map.Entry<String, String[]> entry : renames.entrySet()) {
+            for (Map.Entry<String, String[]> entry : RENAMES.entrySet()) {
               try {
                 String key = entry.getKey();
                 String value = entry.getValue()[0];
@@ -338,19 +338,19 @@ public class JdbcExtractionNamespaceTest
     final String statementVal = val != null ? "'%s'" : "%s";
     if (tsColumn == null) {
       handle.createStatement(
-          StringUtils.format("DELETE FROM %s WHERE %s='%s'", tableName, keyName, key)
+          StringUtils.format("DELETE FROM %s WHERE %s='%s'", TABLE_NAME, KEY_NAME, key)
       ).setQueryTimeout(1).execute();
       query = StringUtils.format(
           "INSERT INTO %s (%s, %s, %s) VALUES ('%s', '%s', " + statementVal + ")",
-          tableName,
+          TABLE_NAME,
-          filterColumn, keyName, valName,
+          FILTER_COLUMN, KEY_NAME, VAL_NAME,
           filter, key, val
       );
     } else {
       query = StringUtils.format(
           "INSERT INTO %s (%s, %s, %s, %s) VALUES ('%s', '%s', '%s', " + statementVal + ")",
-          tableName,
+          TABLE_NAME,
-          tsColumn, filterColumn, keyName, valName,
+          tsColumn, FILTER_COLUMN, KEY_NAME, VAL_NAME,
           updateTs, filter, key, val
       );
     }
@@ -367,9 +367,9 @@ public class JdbcExtractionNamespaceTest
   {
     final JdbcExtractionNamespace extractionNamespace = new JdbcExtractionNamespace(
         derbyConnectorRule.getMetadataConnectorConfig(),
-        tableName,
+        TABLE_NAME,
-        keyName,
+        KEY_NAME,
-        valName,
+        VAL_NAME,
         tsColumn,
         null,
         new Period(0)
@@ -378,7 +378,7 @@ public class JdbcExtractionNamespaceTest
       CacheSchedulerTest.waitFor(entry);
       final Map<String, String> map = entry.getCache();
 
-      for (Map.Entry<String, String[]> e : renames.entrySet()) {
+      for (Map.Entry<String, String[]> e : RENAMES.entrySet()) {
         String key = e.getKey();
         String[] val = e.getValue();
         String field = val[0];
@@ -398,18 +398,18 @@ public class JdbcExtractionNamespaceTest
   {
     final JdbcExtractionNamespace extractionNamespace = new JdbcExtractionNamespace(
         derbyConnectorRule.getMetadataConnectorConfig(),
-        tableName,
+        TABLE_NAME,
-        keyName,
+        KEY_NAME,
-        valName,
+        VAL_NAME,
         tsColumn,
-        filterColumn + "='1'",
+        FILTER_COLUMN + "='1'",
         new Period(0)
     );
     try (CacheScheduler.Entry entry = scheduler.schedule(extractionNamespace)) {
       CacheSchedulerTest.waitFor(entry);
       final Map<String, String> map = entry.getCache();
 
-      for (Map.Entry<String, String[]> e : renames.entrySet()) {
+      for (Map.Entry<String, String[]> e : RENAMES.entrySet()) {
         String key = e.getKey();
         String[] val = e.getValue();
         String field = val[0];
@@ -470,9 +470,9 @@ public class JdbcExtractionNamespaceTest
   {
     final JdbcExtractionNamespace extractionNamespace = new JdbcExtractionNamespace(
         derbyConnectorRule.getMetadataConnectorConfig(),
-        tableName,
+        TABLE_NAME,
-        keyName,
+        KEY_NAME,
-        valName,
+        VAL_NAME,
         tsColumn,
         "some filter",
         new Period(10)
@@ -491,9 +491,9 @@ public class JdbcExtractionNamespaceTest
   {
     final JdbcExtractionNamespace extractionNamespace = new JdbcExtractionNamespace(
         derbyConnectorRule.getMetadataConnectorConfig(),
-        tableName,
+        TABLE_NAME,
-        keyName,
+        KEY_NAME,
-        valName,
+        VAL_NAME,
         tsColumn,
         null,
         new Period(10)

extensions-core/lookups-cached-single/src/test/java/org/apache/druid/server/lookup/PollingLookupTest.java

@@ -47,14 +47,14 @@ import java.util.Map;
 @RunWith(Parameterized.class)
 public class PollingLookupTest
 {
-  private static final Map<String, String> firstLookupMap = ImmutableMap.of(
+  private static final Map<String, String> FIRST_LOOKUP_MAP = ImmutableMap.of(
       "foo", "bar",
       "bad", "bar",
       "how about that", "foo",
       "empty string", ""
   );
 
-  private static final Map<String, String> secondLookupMap = ImmutableMap.of(
+  private static final Map<String, String> SECOND_LOOKUP_MAP = ImmutableMap.of(
       "new-foo", "new-bar",
       "new-bad", "new-bar"
   );
@@ -71,9 +71,9 @@ public class PollingLookupTest
     {
       if (callNumber == 0) {
         callNumber++;
-        return firstLookupMap.entrySet();
+        return FIRST_LOOKUP_MAP.entrySet();
       }
-      return secondLookupMap.entrySet();
+      return SECOND_LOOKUP_MAP.entrySet();
     }
 
     @Nullable
@@ -145,15 +145,15 @@ public class PollingLookupTest
   @Test
   public void testApply()
   {
-    assertMapLookup(firstLookupMap, pollingLookup);
+    assertMapLookup(FIRST_LOOKUP_MAP, pollingLookup);
   }
 
   @Test(timeout = POLL_PERIOD * 3)
   public void testApplyAfterDataChange() throws InterruptedException
   {
-    assertMapLookup(firstLookupMap, pollingLookup);
+    assertMapLookup(FIRST_LOOKUP_MAP, pollingLookup);
     Thread.sleep(POLL_PERIOD * 2);
-    assertMapLookup(secondLookupMap, pollingLookup);
+    assertMapLookup(SECOND_LOOKUP_MAP, pollingLookup);
   }
 
   @Test
@@ -184,8 +184,8 @@ public class PollingLookupTest
   @Test
   public void testBulkApply()
   {
-    Map<String, String> map = pollingLookup.applyAll(firstLookupMap.keySet());
+    Map<String, String> map = pollingLookup.applyAll(FIRST_LOOKUP_MAP.keySet());
-    Assert.assertEquals(firstLookupMap, Maps.transformValues(map, new Function<String, String>()
+    Assert.assertEquals(FIRST_LOOKUP_MAP, Maps.transformValues(map, new Function<String, String>()
     {
       @Override
       public String apply(String input)

extensions-core/lookups-cached-single/src/test/java/org/apache/druid/server/lookup/jdbc/JdbcDataFetcherTest.java

@@ -50,7 +50,7 @@ public class JdbcDataFetcherTest
   
   
 
-  private static final Map<String, String> lookupMap = ImmutableMap.of(
+  private static final Map<String, String> LOOKUP_MAP = ImmutableMap.of(
       "foo", "bar",
       "bad", "bar",
       "how about that", "foo",
@@ -77,7 +77,7 @@ public class JdbcDataFetcherTest
     );
     handle.createStatement(StringUtils.format("TRUNCATE TABLE %s", tableName)).setQueryTimeout(1).execute();
 
-    for (Map.Entry<String, String> entry : lookupMap.entrySet()) {
+    for (Map.Entry<String, String> entry : LOOKUP_MAP.entrySet()) {
       insertValues(entry.getKey(), entry.getValue(), handle);
     }
     handle.commit();
@@ -94,7 +94,7 @@ public class JdbcDataFetcherTest
   public void testFetch()
   {
     Assert.assertEquals("null check", null, jdbcDataFetcher.fetch("baz"));
-    assertMapLookup(lookupMap, jdbcDataFetcher);
+    assertMapLookup(LOOKUP_MAP, jdbcDataFetcher);
   }
 
   @Test
@@ -102,15 +102,15 @@ public class JdbcDataFetcherTest
   {
     ImmutableMap.Builder<String, String> mapBuilder = ImmutableMap.builder();
     jdbcDataFetcher.fetchAll().forEach(mapBuilder::put);
-    Assert.assertEquals("maps should match", lookupMap, mapBuilder.build());
+    Assert.assertEquals("maps should match", LOOKUP_MAP, mapBuilder.build());
   }
 
   @Test
   public void testFetchKeys()
   {
     ImmutableMap.Builder<String, String> mapBuilder = ImmutableMap.builder();
-    jdbcDataFetcher.fetch(lookupMap.keySet()).forEach(mapBuilder::put);
+    jdbcDataFetcher.fetch(LOOKUP_MAP.keySet()).forEach(mapBuilder::put);
-    Assert.assertEquals(lookupMap, mapBuilder.build());
+    Assert.assertEquals(LOOKUP_MAP, mapBuilder.build());
   }
 
   @Test

extensions-core/s3-extensions/src/main/java/org/apache/druid/storage/s3/S3DataSegmentPuller.java

@@ -57,7 +57,7 @@ public class S3DataSegmentPuller implements URIDataPuller
 {
   public static final int DEFAULT_RETRY_COUNT = 3;
 
-  public static final String scheme = S3StorageDruidModule.SCHEME;
+  public static final String SCHEME = S3StorageDruidModule.SCHEME;
 
   private static final Logger log = new Logger(S3DataSegmentPuller.class);
 
@@ -141,8 +141,8 @@ public class S3DataSegmentPuller implements URIDataPuller
 
   public static URI checkURI(URI uri)
   {
-    if (uri.getScheme().equalsIgnoreCase(scheme)) {
+    if (uri.getScheme().equalsIgnoreCase(SCHEME)) {
-      uri = URI.create("s3" + uri.toString().substring(scheme.length()));
+      uri = URI.create("s3" + uri.toString().substring(SCHEME.length()));
     } else if (!"s3".equalsIgnoreCase(uri.getScheme())) {
       throw new IAE("Don't know how to load scheme for URI [%s]", uri.toString());
     }

extensions-core/s3-extensions/src/test/java/org/apache/druid/firehose/s3/StaticS3FirehoseFactoryTest.java

@@ -57,9 +57,9 @@ import java.util.stream.Collectors;
  */
 public class StaticS3FirehoseFactoryTest
 {
-  private static final AmazonS3Client S3_ClIENT = EasyMock.createNiceMock(AmazonS3Client.class);
+  private static final AmazonS3Client S3_CLIENT = EasyMock.createNiceMock(AmazonS3Client.class);
   private static final ServerSideEncryptingAmazonS3 SERVICE = new ServerSideEncryptingAmazonS3(
-      S3_ClIENT,
+      S3_CLIENT,
       new NoopServerSideEncryption()
   );
 
@@ -102,7 +102,7 @@ public class StaticS3FirehoseFactoryTest
     uris.sort(Comparator.comparing(URI::toString));
 
     uris.forEach(StaticS3FirehoseFactoryTest::addExpectedObjject);
-    EasyMock.replay(S3_ClIENT);
+    EasyMock.replay(S3_CLIENT);
 
     final StaticS3FirehoseFactory factory = new StaticS3FirehoseFactory(
         SERVICE,

extensions-core/s3-extensions/src/test/java/org/apache/druid/storage/s3/S3DataSegmentMoverTest.java

@@ -51,7 +51,7 @@ import java.util.Set;
 
 public class S3DataSegmentMoverTest
 {
-  private static final DataSegment sourceSegment = new DataSegment(
+  private static final DataSegment SOURCE_SEGMENT = new DataSegment(
       "test",
       Intervals.of("2013-01-01/2013-01-02"),
       "1",
@@ -80,7 +80,7 @@ public class S3DataSegmentMoverTest
     );
 
     DataSegment movedSegment = mover.move(
-        sourceSegment,
+        SOURCE_SEGMENT,
         ImmutableMap.of("baseKey", "targetBaseKey", "bucket", "archive")
     );
 
@@ -102,7 +102,7 @@ public class S3DataSegmentMoverTest
     );
 
     DataSegment movedSegment = mover.move(
-        sourceSegment,
+        SOURCE_SEGMENT,
         ImmutableMap.of("baseKey", "targetBaseKey", "bucket", "archive")
     );
 
@@ -120,7 +120,7 @@ public class S3DataSegmentMoverTest
     S3DataSegmentMover mover = new S3DataSegmentMover(mockS3Client, new S3DataSegmentPusherConfig());
 
     mover.move(
-        sourceSegment,
+        SOURCE_SEGMENT,
         ImmutableMap.of("baseKey", "targetBaseKey", "bucket", "archive")
     );
   }

extensions-core/s3-extensions/src/test/java/org/apache/druid/storage/s3/S3DataSegmentPusherConfigTest.java

@@ -33,7 +33,7 @@ import java.util.Set;
 
 public class S3DataSegmentPusherConfigTest
 {
-  private static final ObjectMapper jsonMapper = new DefaultObjectMapper();
+  private static final ObjectMapper JSON_MAPPER = new DefaultObjectMapper();
 
   @Test
   public void testSerialization() throws IOException
@@ -41,8 +41,8 @@ public class S3DataSegmentPusherConfigTest
     String jsonConfig = "{\"bucket\":\"bucket1\",\"baseKey\":\"dataSource1\","
                         + "\"disableAcl\":false,\"maxListingLength\":2000,\"useS3aSchema\":false}";
 
-    S3DataSegmentPusherConfig config = jsonMapper.readValue(jsonConfig, S3DataSegmentPusherConfig.class);
+    S3DataSegmentPusherConfig config = JSON_MAPPER.readValue(jsonConfig, S3DataSegmentPusherConfig.class);
-    Assert.assertEquals(jsonConfig, jsonMapper.writeValueAsString(config));
+    Assert.assertEquals(jsonConfig, JSON_MAPPER.writeValueAsString(config));
   }
 
   @Test
@@ -52,8 +52,8 @@ public class S3DataSegmentPusherConfigTest
     String expectedJsonConfig = "{\"bucket\":\"bucket1\",\"baseKey\":\"dataSource1\","
                                 + "\"disableAcl\":false,\"maxListingLength\":1000,\"useS3aSchema\":false}";
 
-    S3DataSegmentPusherConfig config = jsonMapper.readValue(jsonConfig, S3DataSegmentPusherConfig.class);
+    S3DataSegmentPusherConfig config = JSON_MAPPER.readValue(jsonConfig, S3DataSegmentPusherConfig.class);
-    Assert.assertEquals(expectedJsonConfig, jsonMapper.writeValueAsString(config));
+    Assert.assertEquals(expectedJsonConfig, JSON_MAPPER.writeValueAsString(config));
   }
 
   @Test
@@ -63,7 +63,7 @@ public class S3DataSegmentPusherConfigTest
                         + "\"disableAcl\":false,\"maxListingLength\":-1}";
     Validator validator = Validation.buildDefaultValidatorFactory().getValidator();
 
-    S3DataSegmentPusherConfig config = jsonMapper.readValue(jsonConfig, S3DataSegmentPusherConfig.class);
+    S3DataSegmentPusherConfig config = JSON_MAPPER.readValue(jsonConfig, S3DataSegmentPusherConfig.class);
     Set<ConstraintViolation<S3DataSegmentPusherConfig>> violations = validator.validate(config);
     Assert.assertEquals(1, violations.size());
     ConstraintViolation violation = Iterators.getOnlyElement(violations.iterator());

extensions-core/stats/src/main/java/org/apache/druid/query/aggregation/variance/VarianceSerde.java

@@ -38,7 +38,7 @@ import java.util.List;
  */
 public class VarianceSerde extends ComplexMetricSerde
 {
-  private static final Ordering<VarianceAggregatorCollector> comparator =
+  private static final Ordering<VarianceAggregatorCollector> COMPARATOR =
       Ordering.from(VarianceAggregatorCollector.COMPARATOR).nullsFirst();
 
   @Override
@@ -114,7 +114,7 @@ public class VarianceSerde extends ComplexMetricSerde
       @Override
       public int compare(VarianceAggregatorCollector o1, VarianceAggregatorCollector o2)
       {
-        return comparator.compare(o1, o2);
+        return COMPARATOR.compare(o1, o2);
       }
     };
   }

extensions-core/stats/src/test/java/org/apache/druid/query/aggregation/variance/VarianceAggregatorCollectorTest.java

@@ -34,7 +34,7 @@ import java.util.concurrent.ThreadLocalRandom;
 
 public class VarianceAggregatorCollectorTest
 {
-  private static final float[] market_upfront = new float[]{
+  private static final float[] MARKET_UPFRONT = new float[]{
       800.0f, 800.0f, 826.0602f, 1564.6177f, 1006.4021f, 869.64374f, 809.04175f, 1458.4027f, 852.4375f, 879.9881f,
       950.1468f, 712.7746f, 846.2675f, 682.8855f, 1109.875f, 594.3817f, 870.1159f, 677.511f, 1410.2781f, 1219.4321f,
       979.306f, 1224.5016f, 1215.5898f, 716.6092f, 1301.0233f, 786.3633f, 989.9315f, 1609.0967f, 1023.2952f, 1367.6381f,
@@ -57,7 +57,7 @@ public class VarianceAggregatorCollectorTest
       989.0328f, 744.7446f, 1166.4012f, 753.105f, 962.7312f, 780.272f
   };
 
-  private static final float[] market_total_market = new float[]{
+  private static final float[] MARKET_TOTAL_MARKET = new float[]{
       1000.0f, 1000.0f, 1040.9456f, 1689.0128f, 1049.142f, 1073.4766f, 1007.36554f, 1545.7089f, 1016.9652f, 1077.6127f,
       1075.0896f, 953.9954f, 1022.7833f, 937.06195f, 1156.7448f, 849.8775f, 1066.208f, 904.34064f, 1240.5255f,
       1343.2325f, 1088.9431f, 1349.2544f, 1102.8667f, 939.2441f, 1109.8754f, 997.99457f, 1037.4495f, 1686.4197f,
@@ -85,7 +85,7 @@ public class VarianceAggregatorCollectorTest
   public void testVariance()
   {
     Random random = ThreadLocalRandom.current();
-    for (float[] values : Arrays.asList(market_upfront, market_total_market)) {
+    for (float[] values : Arrays.asList(MARKET_UPFRONT, MARKET_TOTAL_MARKET)) {
       double sum = 0;
       for (float f : values) {
         sum += f;

extensions-core/stats/src/test/java/org/apache/druid/query/aggregation/variance/VarianceGroupByQueryTest.java

@@ -96,12 +96,12 @@ public class VarianceGroupByQueryTest
   {
     GroupByQuery query = GroupByQuery
         .builder()
-        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setDataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .setQuerySegmentSpec(QueryRunnerTestHelper.firstToThird)
+        .setQuerySegmentSpec(QueryRunnerTestHelper.FIRST_TO_THIRD)
         .setDimensions(new DefaultDimensionSpec("quality", "alias"))
-        .setAggregatorSpecs(VarianceTestHelper.indexVarianceAggr)
+        .setAggregatorSpecs(VarianceTestHelper.INDEX_VARIANCE_AGGR)
-        .setPostAggregatorSpecs(Collections.singletonList(VarianceTestHelper.stddevOfIndexPostAggr))
+        .setPostAggregatorSpecs(Collections.singletonList(VarianceTestHelper.STD_DEV_OF_INDEX_POST_AGGR))
-        .setGranularity(QueryRunnerTestHelper.dayGran)
+        .setGranularity(QueryRunnerTestHelper.DAY_GRAN)
         .build();
 
     VarianceTestHelper.RowBuilder builder =
@@ -138,16 +138,16 @@ public class VarianceGroupByQueryTest
   {
     GroupByQuery query = GroupByQuery
         .builder()
-        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setDataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .setQuerySegmentSpec(QueryRunnerTestHelper.firstToThird)
+        .setQuerySegmentSpec(QueryRunnerTestHelper.FIRST_TO_THIRD)
         .setDimensions(new DefaultDimensionSpec("quality", "alias"))
         .setAggregatorSpecs(
-            QueryRunnerTestHelper.rowsCount,
+            QueryRunnerTestHelper.ROWS_COUNT,
-            VarianceTestHelper.indexVarianceAggr,
+            VarianceTestHelper.INDEX_VARIANCE_AGGR,
             new LongSumAggregatorFactory("idx", "index")
         )
-        .setPostAggregatorSpecs(Collections.singletonList(VarianceTestHelper.stddevOfIndexPostAggr))
+        .setPostAggregatorSpecs(Collections.singletonList(VarianceTestHelper.STD_DEV_OF_INDEX_POST_AGGR))
-        .setGranularity(QueryRunnerTestHelper.dayGran)
+        .setGranularity(QueryRunnerTestHelper.DAY_GRAN)
         .build();
 
     VarianceTestHelper.RowBuilder builder =
@@ -188,20 +188,20 @@ public class VarianceGroupByQueryTest
 
     GroupByQuery query = GroupByQuery
         .builder()
-        .setDataSource(QueryRunnerTestHelper.dataSource)
+        .setDataSource(QueryRunnerTestHelper.DATA_SOURCE)
         .setInterval("2011-04-02/2011-04-04")
         .setDimensions(new DefaultDimensionSpec("quality", "alias"))
         .setAggregatorSpecs(
-            QueryRunnerTestHelper.rowsCount,
+            QueryRunnerTestHelper.ROWS_COUNT,
-            QueryRunnerTestHelper.indexLongSum,
+            QueryRunnerTestHelper.INDEX_LONG_SUM,
-            VarianceTestHelper.indexVarianceAggr
+            VarianceTestHelper.INDEX_VARIANCE_AGGR
         )
-        .setPostAggregatorSpecs(ImmutableList.of(VarianceTestHelper.stddevOfIndexPostAggr))
+        .setPostAggregatorSpecs(ImmutableList.of(VarianceTestHelper.STD_DEV_OF_INDEX_POST_AGGR))
         .setGranularity(new PeriodGranularity(new Period("P1M"), null, null))
         .setHavingSpec(
             new OrHavingSpec(
                 ImmutableList.of(
-                    new GreaterThanHavingSpec(VarianceTestHelper.stddevOfIndexMetric, 15L) // 3 rows
+                    new GreaterThanHavingSpec(VarianceTestHelper.STD_DEV_OF_INDEX_METRIC, 15L) // 3 rows
                 )
             )
         )
@@ -220,7 +220,7 @@ public class VarianceGroupByQueryTest
         new DefaultLimitSpec(
             Collections.singletonList(
                 OrderByColumnSpec.asc(
-                    VarianceTestHelper.stddevOfIndexMetric
+                    VarianceTestHelper.STD_DEV_OF_INDEX_METRIC
                 )
             ), 2
         )

extensions-core/stats/src/test/java/org/apache/druid/query/aggregation/variance/VarianceTestHelper.java

@@ -48,26 +48,26 @@ public class VarianceTestHelper extends QueryRunnerTestHelper
     module.configure(null);
   }
 
-  public static final String indexVarianceMetric = "index_var";
+  public static final String INDEX_VARIANCE_METRIC = "index_var";
 
-  public static final VarianceAggregatorFactory indexVarianceAggr = new VarianceAggregatorFactory(
+  public static final VarianceAggregatorFactory INDEX_VARIANCE_AGGR = new VarianceAggregatorFactory(
-      indexVarianceMetric,
+      INDEX_VARIANCE_METRIC,
-      indexMetric
+      INDEX_METRIC
   );
 
-  public static final String stddevOfIndexMetric = "index_stddev";
+  public static final String STD_DEV_OF_INDEX_METRIC = "index_stddev";
 
-  public static final PostAggregator stddevOfIndexPostAggr = new StandardDeviationPostAggregator(
+  public static final PostAggregator STD_DEV_OF_INDEX_POST_AGGR = new StandardDeviationPostAggregator(
-      stddevOfIndexMetric,
+      STD_DEV_OF_INDEX_METRIC,
-      indexVarianceMetric,
+      INDEX_VARIANCE_METRIC,
       null
   );
 
-  public static final List<AggregatorFactory> commonPlusVarAggregators = Arrays.asList(
+  public static final List<AggregatorFactory> COMMON_PLUS_VAR_AGGREGATORS = Arrays.asList(
-      rowsCount,
+      ROWS_COUNT,
-      indexDoubleSum,
+      INDEX_DOUBLE_SUM,
-      qualityUniques,
+      QUALITY_UNIQUES,
-      indexVarianceAggr
+      INDEX_VARIANCE_AGGR
   );
 
   public static class RowBuilder

extensions-core/stats/src/test/java/org/apache/druid/query/aggregation/variance/VarianceTimeseriesQueryTest.java

@@ -70,14 +70,14 @@ public class VarianceTimeseriesQueryTest
   public void testTimeseriesWithNullFilterOnNonExistentDimension()
   {
     TimeseriesQuery query = Druids.newTimeseriesQueryBuilder()
-                                  .dataSource(QueryRunnerTestHelper.dataSource)
+                                  .dataSource(QueryRunnerTestHelper.DATA_SOURCE)
-                                  .granularity(QueryRunnerTestHelper.dayGran)
+                                  .granularity(QueryRunnerTestHelper.DAY_GRAN)
                                   .filters("bobby", null)
-                                  .intervals(QueryRunnerTestHelper.firstToThird)
+                                  .intervals(QueryRunnerTestHelper.FIRST_TO_THIRD)
-                                  .aggregators(VarianceTestHelper.commonPlusVarAggregators)
+                                  .aggregators(VarianceTestHelper.COMMON_PLUS_VAR_AGGREGATORS)
                                   .postAggregators(
-                                      QueryRunnerTestHelper.addRowsIndexConstant,
+                                      QueryRunnerTestHelper.ADD_ROWS_INDEX_CONSTANT,
-                                      VarianceTestHelper.stddevOfIndexPostAggr
+                                      VarianceTestHelper.STD_DEV_OF_INDEX_POST_AGGR
                                   )
                                   .descending(descending)
                                   .build();

extensions-core/stats/src/test/java/org/apache/druid/query/aggregation/variance/VarianceTopNQueryTest.java

@@ -68,16 +68,16 @@ public class VarianceTopNQueryTest
   public void testFullOnTopNOverUniques()
   {
     TopNQuery query = new TopNQueryBuilder()
-        .dataSource(QueryRunnerTestHelper.dataSource)
+        .dataSource(QueryRunnerTestHelper.DATA_SOURCE)
-        .granularity(QueryRunnerTestHelper.allGran)
+        .granularity(QueryRunnerTestHelper.ALL_GRAN)
-        .dimension(QueryRunnerTestHelper.marketDimension)
+        .dimension(QueryRunnerTestHelper.MARKET_DIMENSION)
-        .metric(QueryRunnerTestHelper.uniqueMetric)
+        .metric(QueryRunnerTestHelper.UNIQUE_METRIC)
         .threshold(3)
-        .intervals(QueryRunnerTestHelper.fullOnIntervalSpec)
+        .intervals(QueryRunnerTestHelper.FULL_ON_INTERVAL_SPEC)
         .aggregators(
             Lists.newArrayList(
                 Iterables.concat(
-                    VarianceTestHelper.commonPlusVarAggregators,
+                    VarianceTestHelper.COMMON_PLUS_VAR_AGGREGATORS,
                     Lists.newArrayList(
                         new DoubleMaxAggregatorFactory("maxIndex", "index"),
                         new DoubleMinAggregatorFactory("minIndex", "index")
@@ -85,7 +85,7 @@ public class VarianceTopNQueryTest
                 )
             )
         )
-        .postAggregators(QueryRunnerTestHelper.addRowsIndexConstant)
+        .postAggregators(QueryRunnerTestHelper.ADD_ROWS_INDEX_CONSTANT)
         .build();
 
     List<Result<TopNResultValue>> expectedResults = Collections.singletonList(

hll/src/main/java/org/apache/druid/hll/ByteBitLookup.java

@@ -23,266 +23,266 @@ package org.apache.druid.hll;
  */
 public class ByteBitLookup
 {
-  public static final byte[] lookup;
+  public static final byte[] LOOKUP;
 
   static {
-    lookup = new byte[256];
+    LOOKUP = new byte[256];
 
-    lookup[0] = 0;
+    LOOKUP[0] = 0;
-    lookup[1] = 1;
+    LOOKUP[1] = 1;
-    lookup[2] = 2;
+    LOOKUP[2] = 2;
-    lookup[3] = 1;
+    LOOKUP[3] = 1;
-    lookup[4] = 3;
+    LOOKUP[4] = 3;
-    lookup[5] = 1;
+    LOOKUP[5] = 1;
-    lookup[6] = 2;
+    LOOKUP[6] = 2;
-    lookup[7] = 1;
+    LOOKUP[7] = 1;
-    lookup[8] = 4;
+    LOOKUP[8] = 4;
-    lookup[9] = 1;
+    LOOKUP[9] = 1;
-    lookup[10] = 2;
+    LOOKUP[10] = 2;
-    lookup[11] = 1;
+    LOOKUP[11] = 1;
-    lookup[12] = 3;
+    LOOKUP[12] = 3;
-    lookup[13] = 1;
+    LOOKUP[13] = 1;
-    lookup[14] = 2;
+    LOOKUP[14] = 2;
-    lookup[15] = 1;
+    LOOKUP[15] = 1;
-    lookup[16] = 5;
+    LOOKUP[16] = 5;
-    lookup[17] = 1;
+    LOOKUP[17] = 1;
-    lookup[18] = 2;
+    LOOKUP[18] = 2;
-    lookup[19] = 1;
+    LOOKUP[19] = 1;
-    lookup[20] = 3;
+    LOOKUP[20] = 3;
-    lookup[21] = 1;
+    LOOKUP[21] = 1;
-    lookup[22] = 2;
+    LOOKUP[22] = 2;
-    lookup[23] = 1;
+    LOOKUP[23] = 1;
-    lookup[24] = 4;
+    LOOKUP[24] = 4;
-    lookup[25] = 1;
+    LOOKUP[25] = 1;
-    lookup[26] = 2;
+    LOOKUP[26] = 2;
-    lookup[27] = 1;
+    LOOKUP[27] = 1;
-    lookup[28] = 3;
+    LOOKUP[28] = 3;
-    lookup[29] = 1;
+    LOOKUP[29] = 1;
-    lookup[30] = 2;
+    LOOKUP[30] = 2;
-    lookup[31] = 1;
+    LOOKUP[31] = 1;
-    lookup[32] = 6;
+    LOOKUP[32] = 6;
-    lookup[33] = 1;
+    LOOKUP[33] = 1;
-    lookup[34] = 2;
+    LOOKUP[34] = 2;
-    lookup[35] = 1;
+    LOOKUP[35] = 1;
-    lookup[36] = 3;
+    LOOKUP[36] = 3;
-    lookup[37] = 1;
+    LOOKUP[37] = 1;
-    lookup[38] = 2;
+    LOOKUP[38] = 2;
-    lookup[39] = 1;
+    LOOKUP[39] = 1;
-    lookup[40] = 4;
+    LOOKUP[40] = 4;
-    lookup[41] = 1;
+    LOOKUP[41] = 1;
-    lookup[42] = 2;
+    LOOKUP[42] = 2;
-    lookup[43] = 1;
+    LOOKUP[43] = 1;
-    lookup[44] = 3;
+    LOOKUP[44] = 3;
-    lookup[45] = 1;
+    LOOKUP[45] = 1;
-    lookup[46] = 2;
+    LOOKUP[46] = 2;
-    lookup[47] = 1;
+    LOOKUP[47] = 1;
-    lookup[48] = 5;
+    LOOKUP[48] = 5;
-    lookup[49] = 1;
+    LOOKUP[49] = 1;
-    lookup[50] = 2;
+    LOOKUP[50] = 2;
-    lookup[51] = 1;
+    LOOKUP[51] = 1;
-    lookup[52] = 3;
+    LOOKUP[52] = 3;
-    lookup[53] = 1;
+    LOOKUP[53] = 1;
-    lookup[54] = 2;
+    LOOKUP[54] = 2;
-    lookup[55] = 1;
+    LOOKUP[55] = 1;
-    lookup[56] = 4;
+    LOOKUP[56] = 4;
-    lookup[57] = 1;
+    LOOKUP[57] = 1;
-    lookup[58] = 2;
+    LOOKUP[58] = 2;
-    lookup[59] = 1;
+    LOOKUP[59] = 1;
-    lookup[60] = 3;
+    LOOKUP[60] = 3;
-    lookup[61] = 1;
+    LOOKUP[61] = 1;
-    lookup[62] = 2;
+    LOOKUP[62] = 2;
-    lookup[63] = 1;
+    LOOKUP[63] = 1;
-    lookup[64] = 7;
+    LOOKUP[64] = 7;
-    lookup[65] = 1;
+    LOOKUP[65] = 1;
-    lookup[66] = 2;
+    LOOKUP[66] = 2;
-    lookup[67] = 1;
+    LOOKUP[67] = 1;
-    lookup[68] = 3;
+    LOOKUP[68] = 3;
-    lookup[69] = 1;
+    LOOKUP[69] = 1;
-    lookup[70] = 2;
+    LOOKUP[70] = 2;
-    lookup[71] = 1;
+    LOOKUP[71] = 1;
-    lookup[72] = 4;
+    LOOKUP[72] = 4;
-    lookup[73] = 1;
+    LOOKUP[73] = 1;
-    lookup[74] = 2;
+    LOOKUP[74] = 2;
-    lookup[75] = 1;
+    LOOKUP[75] = 1;
-    lookup[76] = 3;
+    LOOKUP[76] = 3;
-    lookup[77] = 1;
+    LOOKUP[77] = 1;
-    lookup[78] = 2;
+    LOOKUP[78] = 2;
-    lookup[79] = 1;
+    LOOKUP[79] = 1;
-    lookup[80] = 5;
+    LOOKUP[80] = 5;
-    lookup[81] = 1;
+    LOOKUP[81] = 1;
-    lookup[82] = 2;
+    LOOKUP[82] = 2;
-    lookup[83] = 1;
+    LOOKUP[83] = 1;
-    lookup[84] = 3;
+    LOOKUP[84] = 3;
-    lookup[85] = 1;
+    LOOKUP[85] = 1;
-    lookup[86] = 2;
+    LOOKUP[86] = 2;
-    lookup[87] = 1;
+    LOOKUP[87] = 1;
-    lookup[88] = 4;
+    LOOKUP[88] = 4;
-    lookup[89] = 1;
+    LOOKUP[89] = 1;
-    lookup[90] = 2;
+    LOOKUP[90] = 2;
-    lookup[91] = 1;
+    LOOKUP[91] = 1;
-    lookup[92] = 3;
+    LOOKUP[92] = 3;
-    lookup[93] = 1;
+    LOOKUP[93] = 1;
-    lookup[94] = 2;
+    LOOKUP[94] = 2;
-    lookup[95] = 1;
+    LOOKUP[95] = 1;
-    lookup[96] = 6;
+    LOOKUP[96] = 6;
-    lookup[97] = 1;
+    LOOKUP[97] = 1;
-    lookup[98] = 2;
+    LOOKUP[98] = 2;
-    lookup[99] = 1;
+    LOOKUP[99] = 1;
-    lookup[100] = 3;
+    LOOKUP[100] = 3;
-    lookup[101] = 1;
+    LOOKUP[101] = 1;
-    lookup[102] = 2;
+    LOOKUP[102] = 2;
-    lookup[103] = 1;
+    LOOKUP[103] = 1;
-    lookup[104] = 4;
+    LOOKUP[104] = 4;
-    lookup[105] = 1;
+    LOOKUP[105] = 1;
-    lookup[106] = 2;
+    LOOKUP[106] = 2;
-    lookup[107] = 1;
+    LOOKUP[107] = 1;
-    lookup[108] = 3;
+    LOOKUP[108] = 3;
-    lookup[109] = 1;
+    LOOKUP[109] = 1;
-    lookup[110] = 2;
+    LOOKUP[110] = 2;
-    lookup[111] = 1;
+    LOOKUP[111] = 1;
-    lookup[112] = 5;
+    LOOKUP[112] = 5;
-    lookup[113] = 1;
+    LOOKUP[113] = 1;
-    lookup[114] = 2;
+    LOOKUP[114] = 2;
-    lookup[115] = 1;
+    LOOKUP[115] = 1;
-    lookup[116] = 3;
+    LOOKUP[116] = 3;
-    lookup[117] = 1;
+    LOOKUP[117] = 1;
-    lookup[118] = 2;
+    LOOKUP[118] = 2;
-    lookup[119] = 1;
+    LOOKUP[119] = 1;
-    lookup[120] = 4;
+    LOOKUP[120] = 4;
-    lookup[121] = 1;
+    LOOKUP[121] = 1;
-    lookup[122] = 2;
+    LOOKUP[122] = 2;
-    lookup[123] = 1;
+    LOOKUP[123] = 1;
-    lookup[124] = 3;
+    LOOKUP[124] = 3;
-    lookup[125] = 1;
+    LOOKUP[125] = 1;
-    lookup[126] = 2;
+    LOOKUP[126] = 2;
-    lookup[127] = 1;
+    LOOKUP[127] = 1;
-    lookup[128] = 8;
+    LOOKUP[128] = 8;
-    lookup[129] = 1;
+    LOOKUP[129] = 1;
-    lookup[130] = 2;
+    LOOKUP[130] = 2;
-    lookup[131] = 1;
+    LOOKUP[131] = 1;
-    lookup[132] = 3;
+    LOOKUP[132] = 3;
-    lookup[133] = 1;
+    LOOKUP[133] = 1;
-    lookup[134] = 2;
+    LOOKUP[134] = 2;
-    lookup[135] = 1;
+    LOOKUP[135] = 1;
-    lookup[136] = 4;
+    LOOKUP[136] = 4;
-    lookup[137] = 1;
+    LOOKUP[137] = 1;
-    lookup[138] = 2;
+    LOOKUP[138] = 2;
-    lookup[139] = 1;
+    LOOKUP[139] = 1;
-    lookup[140] = 3;
+    LOOKUP[140] = 3;
-    lookup[141] = 1;
+    LOOKUP[141] = 1;
-    lookup[142] = 2;
+    LOOKUP[142] = 2;
-    lookup[143] = 1;
+    LOOKUP[143] = 1;
-    lookup[144] = 5;
+    LOOKUP[144] = 5;
-    lookup[145] = 1;
+    LOOKUP[145] = 1;
-    lookup[146] = 2;
+    LOOKUP[146] = 2;
-    lookup[147] = 1;
+    LOOKUP[147] = 1;
-    lookup[148] = 3;
+    LOOKUP[148] = 3;
-    lookup[149] = 1;
+    LOOKUP[149] = 1;
-    lookup[150] = 2;
+    LOOKUP[150] = 2;
-    lookup[151] = 1;
+    LOOKUP[151] = 1;
-    lookup[152] = 4;
+    LOOKUP[152] = 4;
-    lookup[153] = 1;
+    LOOKUP[153] = 1;
-    lookup[154] = 2;
+    LOOKUP[154] = 2;
-    lookup[155] = 1;
+    LOOKUP[155] = 1;
-    lookup[156] = 3;
+    LOOKUP[156] = 3;
-    lookup[157] = 1;
+    LOOKUP[157] = 1;
-    lookup[158] = 2;
+    LOOKUP[158] = 2;
-    lookup[159] = 1;
+    LOOKUP[159] = 1;
-    lookup[160] = 6;
+    LOOKUP[160] = 6;
-    lookup[161] = 1;
+    LOOKUP[161] = 1;
-    lookup[162] = 2;
+    LOOKUP[162] = 2;
-    lookup[163] = 1;
+    LOOKUP[163] = 1;
-    lookup[164] = 3;
+    LOOKUP[164] = 3;
-    lookup[165] = 1;
+    LOOKUP[165] = 1;
-    lookup[166] = 2;
+    LOOKUP[166] = 2;
-    lookup[167] = 1;
+    LOOKUP[167] = 1;
-    lookup[168] = 4;
+    LOOKUP[168] = 4;
-    lookup[169] = 1;
+    LOOKUP[169] = 1;
-    lookup[170] = 2;
+    LOOKUP[170] = 2;
-    lookup[171] = 1;
+    LOOKUP[171] = 1;
-    lookup[172] = 3;
+    LOOKUP[172] = 3;
-    lookup[173] = 1;
+    LOOKUP[173] = 1;
-    lookup[174] = 2;
+    LOOKUP[174] = 2;
-    lookup[175] = 1;
+    LOOKUP[175] = 1;
-    lookup[176] = 5;
+    LOOKUP[176] = 5;
-    lookup[177] = 1;
+    LOOKUP[177] = 1;
-    lookup[178] = 2;
+    LOOKUP[178] = 2;
-    lookup[179] = 1;
+    LOOKUP[179] = 1;
-    lookup[180] = 3;
+    LOOKUP[180] = 3;
-    lookup[181] = 1;
+    LOOKUP[181] = 1;
-    lookup[182] = 2;
+    LOOKUP[182] = 2;
-    lookup[183] = 1;
+    LOOKUP[183] = 1;
-    lookup[184] = 4;
+    LOOKUP[184] = 4;
-    lookup[185] = 1;
+    LOOKUP[185] = 1;
-    lookup[186] = 2;
+    LOOKUP[186] = 2;
-    lookup[187] = 1;
+    LOOKUP[187] = 1;
-    lookup[188] = 3;
+    LOOKUP[188] = 3;
-    lookup[189] = 1;
+    LOOKUP[189] = 1;
-    lookup[190] = 2;
+    LOOKUP[190] = 2;
-    lookup[191] = 1;
+    LOOKUP[191] = 1;
-    lookup[192] = 7;
+    LOOKUP[192] = 7;
-    lookup[193] = 1;
+    LOOKUP[193] = 1;
-    lookup[194] = 2;
+    LOOKUP[194] = 2;
-    lookup[195] = 1;
+    LOOKUP[195] = 1;
-    lookup[196] = 3;
+    LOOKUP[196] = 3;
-    lookup[197] = 1;
+    LOOKUP[197] = 1;
-    lookup[198] = 2;
+    LOOKUP[198] = 2;
-    lookup[199] = 1;
+    LOOKUP[199] = 1;
-    lookup[200] = 4;
+    LOOKUP[200] = 4;
-    lookup[201] = 1;
+    LOOKUP[201] = 1;
-    lookup[202] = 2;
+    LOOKUP[202] = 2;
-    lookup[203] = 1;
+    LOOKUP[203] = 1;
-    lookup[204] = 3;
+    LOOKUP[204] = 3;
-    lookup[205] = 1;
+    LOOKUP[205] = 1;
-    lookup[206] = 2;
+    LOOKUP[206] = 2;
-    lookup[207] = 1;
+    LOOKUP[207] = 1;
-    lookup[208] = 5;
+    LOOKUP[208] = 5;
-    lookup[209] = 1;
+    LOOKUP[209] = 1;
-    lookup[210] = 2;
+    LOOKUP[210] = 2;
-    lookup[211] = 1;
+    LOOKUP[211] = 1;
-    lookup[212] = 3;
+    LOOKUP[212] = 3;
-    lookup[213] = 1;
+    LOOKUP[213] = 1;
-    lookup[214] = 2;
+    LOOKUP[214] = 2;
-    lookup[215] = 1;
+    LOOKUP[215] = 1;
-    lookup[216] = 4;
+    LOOKUP[216] = 4;
-    lookup[217] = 1;
+    LOOKUP[217] = 1;
-    lookup[218] = 2;
+    LOOKUP[218] = 2;
-    lookup[219] = 1;
+    LOOKUP[219] = 1;
-    lookup[220] = 3;
+    LOOKUP[220] = 3;
-    lookup[221] = 1;
+    LOOKUP[221] = 1;
-    lookup[222] = 2;
+    LOOKUP[222] = 2;
-    lookup[223] = 1;
+    LOOKUP[223] = 1;
-    lookup[224] = 6;
+    LOOKUP[224] = 6;
-    lookup[225] = 1;
+    LOOKUP[225] = 1;
-    lookup[226] = 2;
+    LOOKUP[226] = 2;
-    lookup[227] = 1;
+    LOOKUP[227] = 1;
-    lookup[228] = 3;
+    LOOKUP[228] = 3;
-    lookup[229] = 1;
+    LOOKUP[229] = 1;
-    lookup[230] = 2;
+    LOOKUP[230] = 2;
-    lookup[231] = 1;
+    LOOKUP[231] = 1;
-    lookup[232] = 4;
+    LOOKUP[232] = 4;
-    lookup[233] = 1;
+    LOOKUP[233] = 1;
-    lookup[234] = 2;
+    LOOKUP[234] = 2;
-    lookup[235] = 1;
+    LOOKUP[235] = 1;
-    lookup[236] = 3;
+    LOOKUP[236] = 3;
-    lookup[237] = 1;
+    LOOKUP[237] = 1;
-    lookup[238] = 2;
+    LOOKUP[238] = 2;
-    lookup[239] = 1;
+    LOOKUP[239] = 1;
-    lookup[240] = 5;
+    LOOKUP[240] = 5;
-    lookup[241] = 1;
+    LOOKUP[241] = 1;
-    lookup[242] = 2;
+    LOOKUP[242] = 2;
-    lookup[243] = 1;
+    LOOKUP[243] = 1;
-    lookup[244] = 3;
+    LOOKUP[244] = 3;
-    lookup[245] = 1;
+    LOOKUP[245] = 1;
-    lookup[246] = 2;
+    LOOKUP[246] = 2;
-    lookup[247] = 1;
+    LOOKUP[247] = 1;
-    lookup[248] = 4;
+    LOOKUP[248] = 4;
-    lookup[249] = 1;
+    LOOKUP[249] = 1;
-    lookup[250] = 2;
+    LOOKUP[250] = 2;
-    lookup[251] = 1;
+    LOOKUP[251] = 1;
-    lookup[252] = 3;
+    LOOKUP[252] = 3;
-    lookup[253] = 1;
+    LOOKUP[253] = 1;
-    lookup[254] = 2;
+    LOOKUP[254] = 2;
-    lookup[255] = 1;
+    LOOKUP[255] = 1;
   }
 }

hll/src/main/java/org/apache/druid/hll/HyperLogLogCollector.java

@@ -64,29 +64,29 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
   public static final double HIGH_CORRECTION_THRESHOLD = TWO_TO_THE_SIXTY_FOUR / 30.0d;
   public static final double CORRECTION_PARAMETER = ALPHA * NUM_BUCKETS * NUM_BUCKETS;
 
-  private static final int bucketMask = 0x7ff;
+  private static final int BUCKET_MASK = 0x7ff;
-  private static final int minBytesRequired = 10;
+  private static final int MIN_BYTES_REQUIRED = 10;
-  private static final int bitsPerBucket = 4;
+  private static final int BITS_PER_BUCKET = 4;
-  private static final int range = (int) Math.pow(2, bitsPerBucket) - 1;
+  private static final int RANGE = (int) Math.pow(2, BITS_PER_BUCKET) - 1;
 
-  private static final double[][] minNumRegisterLookup = new double[64][256];
+  private static final double[][] MIN_NUM_REGISTER_LOOKUP = new double[64][256];
 
   static {
     for (int registerOffset = 0; registerOffset < 64; ++registerOffset) {
       for (int register = 0; register < 256; ++register) {
         final int upper = ((register & 0xf0) >> 4) + registerOffset;
         final int lower = (register & 0x0f) + registerOffset;
-        minNumRegisterLookup[registerOffset][register] = 1.0d / Math.pow(2, upper) + 1.0d / Math.pow(2, lower);
+        MIN_NUM_REGISTER_LOOKUP[registerOffset][register] = 1.0d / Math.pow(2, upper) + 1.0d / Math.pow(2, lower);
       }
     }
   }
 
   // we have to keep track of the number of zeroes in each of the two halves of the byte register (0, 1, or 2)
-  private static final int[] numZeroLookup = new int[256];
+  private static final int[] NUM_ZERO_LOOKUP = new int[256];
 
   static {
-    for (int i = 0; i < numZeroLookup.length; ++i) {
+    for (int i = 0; i < NUM_ZERO_LOOKUP.length; ++i) {
-      numZeroLookup[i] = (((i & 0xf0) == 0) ? 1 : 0) + (((i & 0x0f) == 0) ? 1 : 0);
+      NUM_ZERO_LOOKUP[i] = (((i & 0xf0) == 0) ? 1 : 0) + (((i & 0x0f) == 0) ? 1 : 0);
     }
   }
 
@@ -181,7 +181,7 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
       short position = copy.getShort();
       final int register = (int) copy.get() & 0xff;
       if (overflowValue != 0 && position == overflowPosition) {
-        int upperNibble = ((register & 0xf0) >>> bitsPerBucket) + minNum;
+        int upperNibble = ((register & 0xf0) >>> BITS_PER_BUCKET) + minNum;
         int lowerNibble = (register & 0x0f) + minNum;
         if (isUpperNibble) {
           upperNibble = Math.max(upperNibble, overflowValue);
@@ -191,8 +191,8 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
         e += 1.0d / Math.pow(2, upperNibble) + 1.0d / Math.pow(2, lowerNibble);
         zeroCount += (((upperNibble & 0xf0) == 0) ? 1 : 0) + (((lowerNibble & 0x0f) == 0) ? 1 : 0);
       } else {
-        e += minNumRegisterLookup[minNum][register];
+        e += MIN_NUM_REGISTER_LOOKUP[minNum][register];
-        zeroCount += numZeroLookup[register];
+        zeroCount += NUM_ZERO_LOOKUP[register];
       }
     }
 
@@ -215,7 +215,7 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
     while (copy.hasRemaining()) {
       final int register = (int) copy.get() & 0xff;
       if (overflowValue != 0 && position == overflowPosition) {
-        int upperNibble = ((register & 0xf0) >>> bitsPerBucket) + minNum;
+        int upperNibble = ((register & 0xf0) >>> BITS_PER_BUCKET) + minNum;
         int lowerNibble = (register & 0x0f) + minNum;
         if (isUpperNibble) {
           upperNibble = Math.max(upperNibble, overflowValue);
@@ -225,8 +225,8 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
         e += 1.0d / Math.pow(2, upperNibble) + 1.0d / Math.pow(2, lowerNibble);
         zeroCount += (((upperNibble & 0xf0) == 0) ? 1 : 0) + (((lowerNibble & 0x0f) == 0) ? 1 : 0);
       } else {
-        e += minNumRegisterLookup[minNum][register];
+        e += MIN_NUM_REGISTER_LOOKUP[minNum][register];
-        zeroCount += numZeroLookup[register];
+        zeroCount += NUM_ZERO_LOOKUP[register];
       }
       position++;
     }
@@ -302,20 +302,20 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
 
   public void add(byte[] hashedValue)
   {
-    if (hashedValue.length < minBytesRequired) {
+    if (hashedValue.length < MIN_BYTES_REQUIRED) {
-      throw new IAE("Insufficient bytes, need[%d] got [%d]", minBytesRequired, hashedValue.length);
+      throw new IAE("Insufficient bytes, need[%d] got [%d]", MIN_BYTES_REQUIRED, hashedValue.length);
     }
 
     estimatedCardinality = null;
 
     final ByteBuffer buffer = ByteBuffer.wrap(hashedValue);
 
-    short bucket = (short) (buffer.getShort(hashedValue.length - 2) & bucketMask);
+    short bucket = (short) (buffer.getShort(hashedValue.length - 2) & BUCKET_MASK);
 
     byte positionOf1 = 0;
 
     for (int i = 0; i < 8; ++i) {
-      byte lookupVal = ByteBitLookup.lookup[UnsignedBytes.toInt(hashedValue[i])];
+      byte lookupVal = ByteBitLookup.LOOKUP[UnsignedBytes.toInt(hashedValue[i])];
       switch (lookupVal) {
         case 0:
           positionOf1 += (byte) 8;
@@ -341,10 +341,10 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
     // discard everything outside of the range we care about
     if (positionOf1 <= registerOffset) {
       return;
-    } else if (positionOf1 > (registerOffset + range)) {
+    } else if (positionOf1 > (registerOffset + RANGE)) {
       final byte currMax = getMaxOverflowValue();
       if (positionOf1 > currMax) {
-        if (currMax <= (registerOffset + range)) {
+        if (currMax <= (registerOffset + RANGE)) {
           // this could be optimized by having an add without sanity checks
           add(getMaxOverflowRegister(), currMax);
         }
@@ -665,7 +665,7 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
     final int position = getPayloadBytePosition() + (short) (bucket >> 1);
     final boolean isUpperNibble = ((bucket & 0x1) == 0);
 
-    final byte shiftedPositionOf1 = (isUpperNibble) ? (byte) (positionOf1 << bitsPerBucket) : positionOf1;
+    final byte shiftedPositionOf1 = (isUpperNibble) ? (byte) (positionOf1 << BITS_PER_BUCKET) : positionOf1;
 
     if (storageBuffer.remaining() != getNumBytesForDenseStorage()) {
       convertToDenseStorage();
@@ -712,7 +712,7 @@ public abstract class HyperLogLogCollector implements Comparable<HyperLogLogColl
     final int lowerNibble = currVal & 0x0f;
 
     // subtract the differences so that the nibbles align
-    final int otherUpper = (byteToAdd & 0xf0) - (offsetDiff << bitsPerBucket);
+    final int otherUpper = (byteToAdd & 0xf0) - (offsetDiff << BITS_PER_BUCKET);
     final int otherLower = (byteToAdd & 0x0f) - offsetDiff;
 
     final int newUpper = Math.max(upperNibble, otherUpper);

hll/src/main/java/org/apache/druid/hll/VersionOneHyperLogLogCollector.java

@@ -41,12 +41,12 @@ public class VersionOneHyperLogLogCollector extends HyperLogLogCollector
   public static final int HEADER_NUM_BYTES = 7;
   public static final int NUM_BYTES_FOR_DENSE_STORAGE = NUM_BYTES_FOR_BUCKETS + HEADER_NUM_BYTES;
 
-  private static final ByteBuffer defaultStorageBuffer = ByteBuffer.wrap(new byte[]{VERSION, 0, 0, 0, 0, 0, 0})
+  private static final ByteBuffer DEFAULT_STORAGE_BUFFER = ByteBuffer.wrap(new byte[]{VERSION, 0, 0, 0, 0, 0, 0})
                                                                    .asReadOnlyBuffer();
 
   VersionOneHyperLogLogCollector()
   {
-    super(defaultStorageBuffer.duplicate());
+    super(DEFAULT_STORAGE_BUFFER.duplicate());
   }
 
   VersionOneHyperLogLogCollector(ByteBuffer buffer)

hll/src/test/java/org/apache/druid/hll/HyperLogLogSerdeBenchmarkTest.java

@@ -55,7 +55,7 @@ public class HyperLogLogSerdeBenchmarkTest extends AbstractBenchmark
     this.NUM_HASHES = num_hashes;
   }
 
-  private static final HashFunction hashFunction = Hashing.murmur3_128();
+  private static final HashFunction HASH_FUNCTION = Hashing.murmur3_128();
 
   @Parameterized.Parameters
   public static Collection<Object[]> getParameters()
@@ -216,13 +216,13 @@ public class HyperLogLogSerdeBenchmarkTest extends AbstractBenchmark
   {
     Random rand = new Random(758190);
     for (long i = 0; i < NUM_HASHES; ++i) {
-      collector.add(hashFunction.hashLong(rand.nextLong()).asBytes());
+      collector.add(HASH_FUNCTION.hashLong(rand.nextLong()).asBytes());
     }
   }
 
   private static HashCode getHash(final ByteBuffer byteBuffer)
   {
-    Hasher hasher = hashFunction.newHasher();
+    Hasher hasher = HASH_FUNCTION.newHasher();
     while (byteBuffer.position() < byteBuffer.limit()) {
       hasher.putByte(byteBuffer.get());
     }

indexing-hadoop/src/main/java/org/apache/druid/indexer/HadoopDruidIndexerConfig.java

@@ -83,7 +83,7 @@ import java.util.SortedSet;
  */
 public class HadoopDruidIndexerConfig
 {
-  private static final Injector injector;
+  private static final Injector INJECTOR;
 
   public static final String CONFIG_PROPERTY = "druid.indexer.config";
   public static final Charset JAVA_NATIVE_CHARSET = Charset.forName("Unicode");
@@ -99,7 +99,7 @@ public class HadoopDruidIndexerConfig
 
 
   static {
-    injector = Initialization.makeInjectorWithModules(
+    INJECTOR = Initialization.makeInjectorWithModules(
         GuiceInjectors.makeStartupInjector(),
         ImmutableList.of(
             new Module()
@@ -118,11 +118,11 @@ public class HadoopDruidIndexerConfig
             new IndexingHadoopModule()
         )
     );
-    JSON_MAPPER = injector.getInstance(ObjectMapper.class);
+    JSON_MAPPER = INJECTOR.getInstance(ObjectMapper.class);
-    INDEX_IO = injector.getInstance(IndexIO.class);
+    INDEX_IO = INJECTOR.getInstance(IndexIO.class);
-    INDEX_MERGER_V9 = injector.getInstance(IndexMergerV9.class);
+    INDEX_MERGER_V9 = INJECTOR.getInstance(IndexMergerV9.class);
-    HADOOP_KERBEROS_CONFIG = injector.getInstance(HadoopKerberosConfig.class);
+    HADOOP_KERBEROS_CONFIG = INJECTOR.getInstance(HadoopKerberosConfig.class);
-    DATA_SEGMENT_PUSHER = injector.getInstance(DataSegmentPusher.class);
+    DATA_SEGMENT_PUSHER = INJECTOR.getInstance(DataSegmentPusher.class);
   }
 
   public enum IndexJobCounters

indexing-hadoop/src/main/java/org/apache/druid/indexer/IndexGeneratorJob.java

@@ -317,7 +317,7 @@ public class IndexGeneratorJob implements Jobby
 
   public static class IndexGeneratorMapper extends HadoopDruidIndexerMapper<BytesWritable, BytesWritable>
   {
-    private static final HashFunction hashFunction = Hashing.murmur3_128();
+    private static final HashFunction HASH_FUNCTION = Hashing.murmur3_128();
 
     private AggregatorFactory[] aggregators;
 
@@ -364,7 +364,7 @@ public class IndexGeneratorJob implements Jobby
       final long truncatedTimestamp = granularitySpec.getQueryGranularity()
                                                      .bucketStart(inputRow.getTimestamp())
                                                      .getMillis();
-      final byte[] hashedDimensions = hashFunction.hashBytes(
+      final byte[] hashedDimensions = HASH_FUNCTION.hashBytes(
           HadoopDruidIndexerConfig.JSON_MAPPER.writeValueAsBytes(
               Rows.toGroupKey(
                   truncatedTimestamp,

indexing-hadoop/src/main/java/org/apache/druid/indexer/Utils.java

@@ -53,7 +53,7 @@ import java.util.concurrent.atomic.AtomicBoolean;
 public class Utils
 {
   private static final Logger log = new Logger(Utils.class);
-  private static final ObjectMapper jsonMapper = new DefaultObjectMapper();
+  private static final ObjectMapper JSON_MAPPER = new DefaultObjectMapper();
 
   public static OutputStream makePathAndOutputStream(JobContext job, Path outputPath, boolean deleteExisting)
       throws IOException
@@ -120,7 +120,7 @@ public class Utils
   {
     FileSystem fs = statsPath.getFileSystem(job.getConfiguration());
 
-    return jsonMapper.readValue(
+    return JSON_MAPPER.readValue(
         fs.open(statsPath),
         JacksonUtils.TYPE_REFERENCE_MAP_STRING_OBJECT
     );
@@ -128,7 +128,7 @@ public class Utils
 
   public static void storeStats(JobContext job, Path path, Map<String, Object> stats) throws IOException
   {
-    jsonMapper.writeValue(makePathAndOutputStream(job, path, true), stats);
+    JSON_MAPPER.writeValue(makePathAndOutputStream(job, path, true), stats);
   }
 
   public static String getFailureMessage(Job failedJob, ObjectMapper jsonMapper)

indexing-hadoop/src/test/java/org/apache/druid/indexer/HadoopDruidIndexerConfigTest.java

@@ -45,11 +45,11 @@ import java.util.List;
  */
 public class HadoopDruidIndexerConfigTest
 {
-  private static final ObjectMapper jsonMapper;
+  private static final ObjectMapper JSON_MAPPER;
 
   static {
-    jsonMapper = new DefaultObjectMapper();
+    JSON_MAPPER = new DefaultObjectMapper();
-    jsonMapper.setInjectableValues(new InjectableValues.Std().addValue(ObjectMapper.class, jsonMapper));
+    JSON_MAPPER.setInjectableValues(new InjectableValues.Std().addValue(ObjectMapper.class, JSON_MAPPER));
   }
 
   @Test
@@ -75,7 +75,7 @@ public class HadoopDruidIndexerConfigTest
                 ImmutableList.of(Intervals.of("2010-01-01/P1D"))
             ),
             null,
-            jsonMapper
+            JSON_MAPPER
         ),
         new HadoopIOConfig(ImmutableMap.of("paths", "bar", "type", "static"), null, null),
         new HadoopTuningConfig(
@@ -144,7 +144,7 @@ public class HadoopDruidIndexerConfigTest
                 ImmutableList.of(Intervals.of("2010-01-01/P1D"))
             ),
             null,
-            jsonMapper
+            JSON_MAPPER
         ),
         new HadoopIOConfig(ImmutableMap.of("paths", "bar", "type", "static"), null, null),
         new HadoopTuningConfig(

indexing-hadoop/src/test/java/org/apache/druid/indexer/HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest.java

@@ -51,11 +51,11 @@ import java.util.Map;
  */
 public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
 {
-  private static final String testDatasource = "test";
+  private static final String TEST_DATA_SOURCE = "test";
-  private static final String testDatasource2 = "test2";
+  private static final String TEST_DATA_SOURCE2 = "test2";
-  private static final Interval testDatasourceInterval = Intervals.of("1970/3000");
+  private static final Interval TEST_DATA_SOURCE_INTERVAL = Intervals.of("1970/3000");
-  private static final Interval testDatasourceInterval2 = Intervals.of("2000/2001");
+  private static final Interval TEST_DATA_SOURCE_INTERVAL2 = Intervals.of("2000/2001");
-  private static final Interval testDatasourceIntervalPartial = Intervals.of("2050/3000");
+  private static final Interval TEST_DATA_SOURCE_INTERVAL_PARTIAL = Intervals.of("2050/3000");
 
   private final ObjectMapper jsonMapper;
 
@@ -70,7 +70,7 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
   }
 
   private static final DataSegment SEGMENT = new DataSegment(
-      testDatasource,
+      TEST_DATA_SOURCE,
       Intervals.of("2000/3000"),
       "ver",
       ImmutableMap.of(
@@ -85,7 +85,7 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
   );
 
   private static final DataSegment SEGMENT2 = new DataSegment(
-      testDatasource2,
+      TEST_DATA_SOURCE2,
       Intervals.of("2000/3000"),
       "ver2",
       ImmutableMap.of(
@@ -112,13 +112,13 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
   {
     PathSpec pathSpec = new DatasourcePathSpec(
         null,
-        new DatasourceIngestionSpec(testDatasource, testDatasourceInterval, null, null, null, null, null, false, null),
+        new DatasourceIngestionSpec(TEST_DATA_SOURCE, TEST_DATA_SOURCE_INTERVAL, null, null, null, null, null, false, null),
         null,
         false
     );
     HadoopDruidIndexerConfig config = testRunUpdateSegmentListIfDatasourcePathSpecIsUsed(
         pathSpec,
-        testDatasourceInterval
+        TEST_DATA_SOURCE_INTERVAL
     );
     Assert.assertEquals(
         ImmutableList.of(WindowedDataSegment.of(SEGMENT)),
@@ -132,8 +132,8 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
     PathSpec pathSpec = new DatasourcePathSpec(
         null,
         new DatasourceIngestionSpec(
-            testDatasource,
+            TEST_DATA_SOURCE,
-            testDatasourceInterval,
+            TEST_DATA_SOURCE_INTERVAL,
             null,
             ImmutableList.of(SEGMENT),
             null,
@@ -147,7 +147,7 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
     );
     HadoopDruidIndexerConfig config = testRunUpdateSegmentListIfDatasourcePathSpecIsUsed(
         pathSpec,
-        testDatasourceInterval
+        TEST_DATA_SOURCE_INTERVAL
     );
     Assert.assertEquals(
         ImmutableList.of(WindowedDataSegment.of(SEGMENT)),
@@ -161,8 +161,8 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
     PathSpec pathSpec = new DatasourcePathSpec(
         null,
         new DatasourceIngestionSpec(
-            testDatasource,
+            TEST_DATA_SOURCE,
-            testDatasourceInterval,
+            TEST_DATA_SOURCE_INTERVAL,
             null,
             ImmutableList.of(SEGMENT.withVersion("v2")),
             null,
@@ -176,7 +176,7 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
     );
     testRunUpdateSegmentListIfDatasourcePathSpecIsUsed(
         pathSpec,
-        testDatasourceInterval
+        TEST_DATA_SOURCE_INTERVAL
     );
   }
 
@@ -187,8 +187,8 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
     PathSpec pathSpec = new DatasourcePathSpec(
         null,
         new DatasourceIngestionSpec(
-            testDatasource,
+            TEST_DATA_SOURCE,
-            testDatasourceIntervalPartial,
+            TEST_DATA_SOURCE_INTERVAL_PARTIAL,
             null,
             null,
             null,
@@ -202,10 +202,10 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
     );
     HadoopDruidIndexerConfig config = testRunUpdateSegmentListIfDatasourcePathSpecIsUsed(
         pathSpec,
-        testDatasourceIntervalPartial
+        TEST_DATA_SOURCE_INTERVAL_PARTIAL
     );
     Assert.assertEquals(
-        ImmutableList.of(new WindowedDataSegment(SEGMENT, testDatasourceIntervalPartial)),
+        ImmutableList.of(new WindowedDataSegment(SEGMENT, TEST_DATA_SOURCE_INTERVAL_PARTIAL)),
         ((DatasourcePathSpec) config.getPathSpec()).getSegments()
     );
   }
@@ -219,8 +219,8 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
             new DatasourcePathSpec(
                 null,
                 new DatasourceIngestionSpec(
-                    testDatasource,
+                    TEST_DATA_SOURCE,
-                    testDatasourceInterval,
+                    TEST_DATA_SOURCE_INTERVAL,
                     null,
                     null,
                     null,
@@ -235,8 +235,8 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
             new DatasourcePathSpec(
                 null,
                 new DatasourceIngestionSpec(
-                    testDatasource2,
+                    TEST_DATA_SOURCE2,
-                    testDatasourceInterval2,
+                    TEST_DATA_SOURCE_INTERVAL2,
                     null,
                     null,
                     null,
@@ -252,14 +252,14 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
     );
     HadoopDruidIndexerConfig config = testRunUpdateSegmentListIfDatasourcePathSpecIsUsed(
         pathSpec,
-        testDatasourceInterval
+        TEST_DATA_SOURCE_INTERVAL
     );
     Assert.assertEquals(
         ImmutableList.of(WindowedDataSegment.of(SEGMENT)),
         ((DatasourcePathSpec) ((MultiplePathSpec) config.getPathSpec()).getChildren().get(1)).getSegments()
     );
     Assert.assertEquals(
-        ImmutableList.of(new WindowedDataSegment(SEGMENT2, testDatasourceInterval2)),
+        ImmutableList.of(new WindowedDataSegment(SEGMENT2, TEST_DATA_SOURCE_INTERVAL2)),
         ((DatasourcePathSpec) ((MultiplePathSpec) config.getPathSpec()).getChildren().get(2)).getSegments()
     );
   }
@@ -300,15 +300,15 @@ public class HadoopIngestionSpecUpdateDatasourcePathSpecSegmentsTest
 
     EasyMock.expect(
         segmentLister.getUsedSegmentsForIntervals(
-            testDatasource,
+            TEST_DATA_SOURCE,
-            Collections.singletonList(jobInterval != null ? jobInterval.overlap(testDatasourceInterval) : null)
+            Collections.singletonList(jobInterval != null ? jobInterval.overlap(TEST_DATA_SOURCE_INTERVAL) : null)
         )
     ).andReturn(ImmutableList.of(SEGMENT));
 
     EasyMock.expect(
         segmentLister.getUsedSegmentsForIntervals(
-            testDatasource2,
+            TEST_DATA_SOURCE2,
-            Collections.singletonList(jobInterval != null ? jobInterval.overlap(testDatasourceInterval2) : null)
+            Collections.singletonList(jobInterval != null ? jobInterval.overlap(TEST_DATA_SOURCE_INTERVAL2) : null)
         )
     ).andReturn(ImmutableList.of(SEGMENT2));
 

indexing-hadoop/src/test/java/org/apache/druid/indexer/HadoopTuningConfigTest.java

@@ -32,7 +32,7 @@ import java.util.List;
  */
 public class HadoopTuningConfigTest
 {
-  private static final ObjectMapper jsonMapper = new DefaultObjectMapper();
+  private static final ObjectMapper JSON_MAPPER = new DefaultObjectMapper();
 
   @Test
   public void testSerde() throws Exception
@@ -64,7 +64,7 @@ public class HadoopTuningConfigTest
         null
     );
 
-    HadoopTuningConfig actual = jsonReadWriteRead(jsonMapper.writeValueAsString(expected), HadoopTuningConfig.class);
+    HadoopTuningConfig actual = jsonReadWriteRead(JSON_MAPPER.writeValueAsString(expected), HadoopTuningConfig.class);
 
     Assert.assertEquals("/tmp/workingpath", actual.getWorkingPath());
     Assert.assertEquals("version", actual.getVersion());
@@ -88,7 +88,7 @@ public class HadoopTuningConfigTest
   public static <T> T jsonReadWriteRead(String s, Class<T> klass)
   {
     try {
-      return jsonMapper.readValue(jsonMapper.writeValueAsBytes(jsonMapper.readValue(s, klass)), klass);
+      return JSON_MAPPER.readValue(JSON_MAPPER.writeValueAsBytes(JSON_MAPPER.readValue(s, klass)), klass);
     }
     catch (Exception e) {
       throw new RuntimeException(e);

indexing-hadoop/src/test/java/org/apache/druid/indexer/IndexGeneratorJobTest.java

@@ -84,12 +84,12 @@ import java.util.TreeMap;
 @RunWith(Parameterized.class)
 public class IndexGeneratorJobTest
 {
-  private static final AggregatorFactory[] aggs1 = {
+  private static final AggregatorFactory[] AGGS1 = {
       new LongSumAggregatorFactory("visited_num", "visited_num"),
       new HyperUniquesAggregatorFactory("unique_hosts", "host")
   };
 
-  private static final AggregatorFactory[] aggs2 = {
+  private static final AggregatorFactory[] AGGS2 = {
       new CountAggregatorFactory("count")
   };
 
@@ -156,7 +156,7 @@ public class IndexGeneratorJobTest
                 ),
                 null,
                 null,
-                aggs1,
+                AGGS1,
                 "website"
             },
             {
@@ -204,7 +204,7 @@ public class IndexGeneratorJobTest
                 ),
                 null,
                 null,
-                aggs1,
+                AGGS1,
                 "website"
             },
             {
@@ -253,7 +253,7 @@ public class IndexGeneratorJobTest
                 ),
                 null,
                 null,
-                aggs1,
+                AGGS1,
                 "website"
             },
             {
@@ -311,7 +311,7 @@ public class IndexGeneratorJobTest
                 ),
                 null,
                 null,
-                aggs1,
+                AGGS1,
                 "website"
             },
             {
@@ -344,7 +344,7 @@ public class IndexGeneratorJobTest
                 ),
                 1, // force 1 row max per index for easier testing
                 null,
-                aggs2,
+                AGGS2,
                 "inherit_dims"
             },
             {
@@ -377,7 +377,7 @@ public class IndexGeneratorJobTest
                 ),
                 1, // force 1 row max per index for easier testing
                 null,
-                aggs2,
+                AGGS2,
                 "inherit_dims2"
             }
         }

indexing-hadoop/src/test/java/org/apache/druid/indexer/updater/MetadataStorageUpdaterJobSpecTest.java

@@ -25,7 +25,7 @@ import org.junit.Test;
 
 public class MetadataStorageUpdaterJobSpecTest
 {
-  private static final ObjectMapper jsonMapper = new ObjectMapper();
+  private static final ObjectMapper JSON_MAPPER = new ObjectMapper();
 
   @Test
   public void testMetadaStorageConnectionConfigSimplePassword() throws Exception
@@ -62,7 +62,7 @@ public class MetadataStorageUpdaterJobSpecTest
       String pwd
   ) throws Exception
   {
-    MetadataStorageUpdaterJobSpec spec = jsonMapper.readValue(
+    MetadataStorageUpdaterJobSpec spec = JSON_MAPPER.readValue(
         "{" +
         "\"type\": \"" + type + "\",\n" +
         "\"connectURI\": \"" + connectURI + "\",\n" +

indexing-service/src/main/java/org/apache/druid/indexing/common/index/RealtimeAppenderatorTuningConfig.java

@@ -39,14 +39,14 @@ import java.io.File;
 @JsonTypeName("realtime_appenderator")
 public class RealtimeAppenderatorTuningConfig implements TuningConfig, AppenderatorConfig
 {
-  private static final int defaultMaxRowsInMemory = TuningConfig.DEFAULT_MAX_ROWS_IN_MEMORY;
+  private static final int DEFAULT_MAX_ROWS_IN_MEMORY = TuningConfig.DEFAULT_MAX_ROWS_IN_MEMORY;
-  private static final Period defaultIntermediatePersistPeriod = new Period("PT10M");
+  private static final Period DEFAULT_INTERMEDIATE_PERSIST_PERIOD = new Period("PT10M");
-  private static final int defaultMaxPendingPersists = 0;
+  private static final int DEFAULT_MAX_PENDING_PERSISTS = 0;
-  private static final ShardSpec defaultShardSpec = new NumberedShardSpec(0, 1);
+  private static final ShardSpec DEFAULT_SHARD_SPEC = new NumberedShardSpec(0, 1);
-  private static final IndexSpec defaultIndexSpec = new IndexSpec();
+  private static final IndexSpec DEFAULT_INDEX_SPEC = new IndexSpec();
-  private static final Boolean defaultReportParseExceptions = Boolean.FALSE;
+  private static final Boolean DEFAULT_REPORT_PARSE_EXCEPTIONS = Boolean.FALSE;
-  private static final long defaultPublishAndHandoffTimeout = 0;
+  private static final long DEFAULT_HANDOFF_CONDITION_TIMEOUT = 0;
-  private static final long defaultAlertTimeout = 0;
+  private static final long DEFAULT_ALERT_TIMEOUT = 0;
 
   private static File createNewBasePersistDirectory()
   {
@@ -93,29 +93,29 @@ public class RealtimeAppenderatorTuningConfig implements TuningConfig, Appendera
       @JsonProperty("maxSavedParseExceptions") @Nullable Integer maxSavedParseExceptions
   )
   {
-    this.maxRowsInMemory = maxRowsInMemory == null ? defaultMaxRowsInMemory : maxRowsInMemory;
+    this.maxRowsInMemory = maxRowsInMemory == null ? DEFAULT_MAX_ROWS_IN_MEMORY : maxRowsInMemory;
     // initializing this to 0, it will be lazily intialized to a value
     // @see server.src.main.java.org.apache.druid.segment.indexing.TuningConfigs#getMaxBytesInMemoryOrDefault(long)
     this.maxBytesInMemory = maxBytesInMemory == null ? 0 : maxBytesInMemory;
     this.partitionsSpec = new DynamicPartitionsSpec(maxRowsPerSegment, maxTotalRows);
     this.intermediatePersistPeriod = intermediatePersistPeriod == null
-                                     ? defaultIntermediatePersistPeriod
+                                     ? DEFAULT_INTERMEDIATE_PERSIST_PERIOD
                                      : intermediatePersistPeriod;
     this.basePersistDirectory = basePersistDirectory == null ? createNewBasePersistDirectory() : basePersistDirectory;
-    this.maxPendingPersists = maxPendingPersists == null ? defaultMaxPendingPersists : maxPendingPersists;
+    this.maxPendingPersists = maxPendingPersists == null ? DEFAULT_MAX_PENDING_PERSISTS : maxPendingPersists;
-    this.shardSpec = shardSpec == null ? defaultShardSpec : shardSpec;
+    this.shardSpec = shardSpec == null ? DEFAULT_SHARD_SPEC : shardSpec;
-    this.indexSpec = indexSpec == null ? defaultIndexSpec : indexSpec;
+    this.indexSpec = indexSpec == null ? DEFAULT_INDEX_SPEC : indexSpec;
     this.indexSpecForIntermediatePersists = indexSpecForIntermediatePersists == null ?
                                             this.indexSpec : indexSpecForIntermediatePersists;
     this.reportParseExceptions = reportParseExceptions == null
-                                 ? defaultReportParseExceptions
+                                 ? DEFAULT_REPORT_PARSE_EXCEPTIONS
                                  : reportParseExceptions;
     this.publishAndHandoffTimeout = publishAndHandoffTimeout == null
-                                    ? defaultPublishAndHandoffTimeout
+                                    ? DEFAULT_HANDOFF_CONDITION_TIMEOUT
                                     : publishAndHandoffTimeout;
     Preconditions.checkArgument(this.publishAndHandoffTimeout >= 0, "publishAndHandoffTimeout must be >= 0");
 
-    this.alertTimeout = alertTimeout == null ? defaultAlertTimeout : alertTimeout;
+    this.alertTimeout = alertTimeout == null ? DEFAULT_ALERT_TIMEOUT : alertTimeout;
     Preconditions.checkArgument(this.alertTimeout >= 0, "alertTimeout must be >= 0");
     this.segmentWriteOutMediumFactory = segmentWriteOutMediumFactory;
 

indexing-service/src/main/java/org/apache/druid/indexing/common/task/HadoopIndexTask.java

@@ -703,7 +703,7 @@ public class HadoopIndexTask extends HadoopTask implements ChatHandler
       // can be injected based on the configuration given in config.getSchema().getIOConfig().getMetadataUpdateSpec()
       final MetadataStorageUpdaterJobHandler maybeHandler;
       if (config.isUpdaterJobSpecSet()) {
-        maybeHandler = injector.getInstance(MetadataStorageUpdaterJobHandler.class);
+        maybeHandler = INJECTOR.getInstance(MetadataStorageUpdaterJobHandler.class);
       } else {
         maybeHandler = null;
       }