Add GenericWhitespace checkstyle check (#5668)

codestyle/checkstyle.xml

@@ -94,6 +94,7 @@
       <property name="tokens" value="DOT"/>
       <property name="allowLineBreaks" value="false"/>
     </module>
+    <module name="GenericWhitespace"/>
 
     <module name="Indentation">
       <property name="basicOffset" value="2"/>

extensions-core/datasketches/src/main/java/io/druid/query/aggregation/datasketches/quantiles/DoublesSketchAggregatorFactory.java

@@ -182,7 +182,7 @@ public class DoublesSketchAggregatorFactory extends AggregatorFactory
   @Override
   public List<AggregatorFactory> getRequiredColumns()
   {
-    return Collections.<AggregatorFactory> singletonList(
+    return Collections.singletonList(
         new DoublesSketchAggregatorFactory(
             fieldName,
             fieldName,

extensions-core/datasketches/src/main/java/io/druid/query/aggregation/datasketches/quantiles/DoublesSketchModule.java

@@ -19,18 +19,17 @@
 
 package io.druid.query.aggregation.datasketches.quantiles;
 
-import java.util.Arrays;
-import java.util.List;
-
 import com.fasterxml.jackson.databind.Module;
 import com.fasterxml.jackson.databind.jsontype.NamedType;
 import com.fasterxml.jackson.databind.module.SimpleModule;
 import com.google.inject.Binder;
 import com.yahoo.sketches.quantiles.DoublesSketch;
-
 import io.druid.initialization.DruidModule;
 import io.druid.segment.serde.ComplexMetrics;
 
+import java.util.Collections;
+import java.util.List;
+
 public class DoublesSketchModule implements DruidModule
 {
 
@@ -53,15 +52,17 @@ public class DoublesSketchModule implements DruidModule
   @Override
   public List<? extends Module> getJacksonModules()
   {
-    return Arrays.<Module> asList(
+    return Collections.<Module>singletonList(
-        new SimpleModule("DoublesQuantilesSketchModule").registerSubtypes(
+        new SimpleModule("DoublesQuantilesSketchModule")
+            .registerSubtypes(
                 new NamedType(DoublesSketchAggregatorFactory.class, DOUBLES_SKETCH),
                 new NamedType(DoublesSketchMergeAggregatorFactory.class, DOUBLES_SKETCH_MERGE),
                 new NamedType(DoublesSketchToHistogramPostAggregator.class, DOUBLES_SKETCH_HISTOGRAM_POST_AGG),
                 new NamedType(DoublesSketchToQuantilePostAggregator.class, DOUBLES_SKETCH_QUANTILE_POST_AGG),
                 new NamedType(DoublesSketchToQuantilesPostAggregator.class, DOUBLES_SKETCH_QUANTILES_POST_AGG),
-            new NamedType(DoublesSketchToStringPostAggregator.class, DOUBLES_SKETCH_TO_STRING_POST_AGG))
+                new NamedType(DoublesSketchToStringPostAggregator.class, DOUBLES_SKETCH_TO_STRING_POST_AGG)
-            .addSerializer(DoublesSketch.class, new DoublesSketchJsonSerializer()));
+            ).addSerializer(DoublesSketch.class, new DoublesSketchJsonSerializer())
+    );
   }
 
 }

processing/src/test/java/io/druid/query/filter/ColumnComparisonDimFilterTest.java

@@ -21,7 +21,6 @@ package io.druid.query.filter;
 
 import com.google.common.collect.ImmutableList;
 import io.druid.query.dimension.DefaultDimensionSpec;
-import io.druid.query.dimension.DimensionSpec;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -32,16 +31,16 @@ public class ColumnComparisonDimFilterTest
   @Test
   public void testGetCacheKey()
   {
-    ColumnComparisonDimFilter columnComparisonDimFilter = new ColumnComparisonDimFilter(ImmutableList.<DimensionSpec> of(
+    ColumnComparisonDimFilter columnComparisonDimFilter = new ColumnComparisonDimFilter(ImmutableList.of(
         DefaultDimensionSpec.of("abc"),
         DefaultDimensionSpec.of("d")
     ));
-    ColumnComparisonDimFilter columnComparisonDimFilter2 = new ColumnComparisonDimFilter(ImmutableList.<DimensionSpec> of(
+    ColumnComparisonDimFilter columnComparisonDimFilter2 = new ColumnComparisonDimFilter(ImmutableList.of(
         DefaultDimensionSpec.of("d"),
         DefaultDimensionSpec.of("abc")
     ));
     ColumnComparisonDimFilter columnComparisonDimFilter3 = new ColumnComparisonDimFilter(
-        ImmutableList.<DimensionSpec> of(
+        ImmutableList.of(
             DefaultDimensionSpec.of("d"),
             DefaultDimensionSpec.of("e")
         )
@@ -61,19 +60,19 @@ public class ColumnComparisonDimFilterTest
   public void testHashCode()
   {
     ColumnComparisonDimFilter columnComparisonDimFilter = new ColumnComparisonDimFilter(
-        ImmutableList.<DimensionSpec> of(
+        ImmutableList.of(
             DefaultDimensionSpec.of("abc"),
             DefaultDimensionSpec.of("d")
         )
     );
     ColumnComparisonDimFilter columnComparisonDimFilter2 = new ColumnComparisonDimFilter(
-        ImmutableList.<DimensionSpec> of(
+        ImmutableList.of(
             DefaultDimensionSpec.of("d"),
             DefaultDimensionSpec.of("abc")
         )
     );
     ColumnComparisonDimFilter columnComparisonDimFilter3 = new ColumnComparisonDimFilter(
-        ImmutableList.<DimensionSpec> of(
+        ImmutableList.of(
             DefaultDimensionSpec.of("d"),
             DefaultDimensionSpec.of("e")
         )

server/src/test/java/io/druid/segment/realtime/appenderator/AppenderatorPlumberTest.java

@@ -19,7 +19,6 @@
 package io.druid.segment.realtime.appenderator;
 
 import io.druid.data.input.InputRow;
-import io.druid.query.SegmentDescriptor;
 import io.druid.segment.indexing.RealtimeTuningConfig;
 import io.druid.segment.realtime.SegmentPublisher;
 import io.druid.segment.realtime.plumber.IntervalStartVersioningPolicy;
@@ -27,14 +26,12 @@ import io.druid.segment.realtime.plumber.NoopRejectionPolicyFactory;
 import io.druid.segment.realtime.plumber.SegmentHandoffNotifier;
 import io.druid.segment.realtime.plumber.SegmentHandoffNotifierFactory;
 import io.druid.server.coordination.DataSegmentAnnouncer;
-import io.druid.timeline.DataSegment;
 import org.easymock.EasyMock;
 import org.junit.Assert;
 import org.junit.Test;
 
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
-import java.util.concurrent.Executor;
 
 public class AppenderatorPlumberTest
 {
@@ -46,7 +43,7 @@ public class AppenderatorPlumberTest
     this.appenderatorTester = new AppenderatorTester(10);
     DataSegmentAnnouncer segmentAnnouncer = EasyMock
         .createMock(DataSegmentAnnouncer.class);
-    segmentAnnouncer.announceSegment(EasyMock.<DataSegment> anyObject());
+    segmentAnnouncer.announceSegment(EasyMock.anyObject());
     EasyMock.expectLastCall().anyTimes();
 
     SegmentPublisher segmentPublisher = EasyMock
@@ -62,9 +59,9 @@ public class AppenderatorPlumberTest
     EasyMock
         .expect(
             handoffNotifier.registerSegmentHandoffCallback(
-                EasyMock.<SegmentDescriptor> anyObject(),
+                EasyMock.anyObject(),
-                EasyMock.<Executor> anyObject(),
+                EasyMock.anyObject(),
-                EasyMock.<Runnable> anyObject())).andReturn(true).anyTimes();
+                EasyMock.anyObject())).andReturn(true).anyTimes();
     
     RealtimeTuningConfig tuningConfig = new RealtimeTuningConfig(
         1,