BAEL-1375 Counter in Java. (#3170)
* BAEL-1375 Counter in Java. * BAEL-1375 Frequency counter in java. * BAEL-1375 Refactored method names.
This commit is contained in:
Muhammed Almas
Grzegorz Piwowarek
parent
41ce086ec6
commit
63d4e7d014
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@ -1,258 +1,276 @@
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||||
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|
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|
||||
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|
||||
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|
||||
|
||||
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|
||||
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|
||||
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||||
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|
||||
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|
||||
|
||||
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|
||||
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|
||||
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||||
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|
||||
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||||
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||||
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||||
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|
||||
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|
||||
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|
||||
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|
||||
|
||||
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|
||||
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|
||||
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|
||||
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|
||||
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|
||||
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|
||||
|
||||
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|
||||
|
||||
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|
||||
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|
||||
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|
||||
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|
||||
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|
||||
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|
||||
|
||||
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|
||||
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|
||||
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|
||||
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|
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||||
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|
||||
<commons-math3.version>3.6.1</commons-math3.version>
|
||||
<commons-io.version>2.5</commons-io.version>
|
||||
<commons-collections4.version>4.1</commons-collections4.version>
|
||||
<collections-generic.version>4.01</collections-generic.version>
|
||||
<commons-codec.version>1.10</commons-codec.version>
|
||||
<lombok.version>1.16.12</lombok.version>
|
||||
|
||||
<!-- testing -->
|
||||
<assertj.version>3.6.1</assertj.version>
|
||||
<avaitility.version>1.7.0</avaitility.version>
|
||||
|
||||
</properties>
|
||||
</project>
|
||||
|
|
@ -0,0 +1,45 @@
|
|||
package com.baeldung.counter;
|
||||
|
||||
import java.util.HashMap;
|
||||
import java.util.Map;
|
||||
|
||||
import org.openjdk.jmh.annotations.Benchmark;
|
||||
import org.openjdk.jmh.annotations.BenchmarkMode;
|
||||
import org.openjdk.jmh.annotations.Fork;
|
||||
import org.openjdk.jmh.annotations.Mode;
|
||||
|
||||
import com.baeldung.counter.CounterUtil.MutableInteger;
|
||||
|
||||
@Fork(value = 1, warmups = 3)
|
||||
@BenchmarkMode(Mode.All)
|
||||
public class CounterStatistics {
|
||||
|
||||
private static final Map<String, Integer> counterMap = new HashMap<>();
|
||||
private static final Map<String, MutableInteger> counterWithMutableIntMap = new HashMap<>();
|
||||
private static final Map<String, int[]> counterWithIntArrayMap = new HashMap<>();
|
||||
private static final Map<String, Long> counterWithLongWrapperMap = new HashMap<>();
|
||||
|
||||
@Benchmark
|
||||
public void wrapperAsCounter() {
|
||||
CounterUtil.counterWithWrapperObject(counterMap);
|
||||
}
|
||||
|
||||
@Benchmark
|
||||
public void lambdaExpressionWithWrapper() {
|
||||
CounterUtil.counterWithLambdaAndWrapper(counterWithLongWrapperMap);
|
||||
}
|
||||
|
||||
@Benchmark
|
||||
public void mutableIntegerAsCounter() {
|
||||
CounterUtil.counterWithMutableInteger(counterWithMutableIntMap);
|
||||
}
|
||||
|
||||
@Benchmark
|
||||
public void primitiveArrayAsCounter() {
|
||||
CounterUtil.counterWithPrimitiveArray(counterWithIntArrayMap);
|
||||
}
|
||||
|
||||
public static void main(String[] args) throws Exception {
|
||||
org.openjdk.jmh.Main.main(args);
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,53 @@
|
|||
package com.baeldung.counter;
|
||||
|
||||
import java.util.HashMap;
|
||||
import java.util.Map;
|
||||
|
||||
import static org.junit.Assert.*;
|
||||
|
||||
import org.junit.Test;
|
||||
|
||||
import com.baeldung.counter.CounterUtil.MutableInteger;
|
||||
|
||||
public class CounterTest {
|
||||
|
||||
@Test
|
||||
public void whenMapWithWrapperAsCounter_runsSuccessfully() {
|
||||
Map<String, Integer> counterMap = new HashMap<>();
|
||||
CounterUtil.counterWithWrapperObject(counterMap);
|
||||
|
||||
assertEquals(3, counterMap.get("China")
|
||||
.intValue());
|
||||
assertEquals(2, counterMap.get("India")
|
||||
.intValue());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenMapWithLambdaAndWrapperCounter_runsSuccessfully() {
|
||||
Map<String, Long> counterMap = new HashMap<>();
|
||||
CounterUtil.counterWithLambdaAndWrapper(counterMap);
|
||||
|
||||
assertEquals(3l, counterMap.get("China")
|
||||
.longValue());
|
||||
assertEquals(2l, counterMap.get("India")
|
||||
.longValue());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenMapWithMutableIntegerCounter_runsSuccessfully() {
|
||||
Map<String, MutableInteger> counterMap = new HashMap<>();
|
||||
CounterUtil.counterWithMutableInteger(counterMap);
|
||||
assertEquals(3, counterMap.get("China")
|
||||
.getCount());
|
||||
assertEquals(2, counterMap.get("India")
|
||||
.getCount());
|
||||
}
|
||||
|
||||
@Test
|
||||
public void whenMapWithPrimitiveArray_runsSuccessfully() {
|
||||
Map<String, int[]> counterMap = new HashMap<>();
|
||||
CounterUtil.counterWithPrimitiveArray(counterMap);
|
||||
assertEquals(3, counterMap.get("China")[0]);
|
||||
assertEquals(2, counterMap.get("India")[0]);
|
||||
}
|
||||
}
|
||||
|
|
@ -0,0 +1,61 @@
|
|||
package com.baeldung.counter;
|
||||
|
||||
import java.util.Map;
|
||||
import java.util.stream.Collectors;
|
||||
import java.util.stream.Stream;
|
||||
|
||||
public class CounterUtil {
|
||||
|
||||
private final static String[] COUNTRY_NAMES = { "China", "Australia", "India", "USA", "USSR", "UK", "China", "France", "Poland", "Austria", "India", "USA", "Egypt", "China" };
|
||||
|
||||
public static void counterWithWrapperObject(Map<String, Integer> counterMap) {
|
||||
for (String country : COUNTRY_NAMES) {
|
||||
counterMap.compute(country, (k, v) -> v == null ? 1 : v + 1);
|
||||
}
|
||||
}
|
||||
|
||||
public static void counterWithLambdaAndWrapper(Map<String, Long> counterMap) {
|
||||
counterMap.putAll(Stream.of(COUNTRY_NAMES)
|
||||
.parallel()
|
||||
.collect(Collectors.groupingBy(k -> k, Collectors.counting())));
|
||||
}
|
||||
|
||||
public static class MutableInteger {
|
||||
int count;
|
||||
|
||||
public MutableInteger(int count) {
|
||||
this.count = count;
|
||||
}
|
||||
|
||||
public void increment() {
|
||||
this.count++;
|
||||
}
|
||||
|
||||
public int getCount() {
|
||||
return this.count;
|
||||
}
|
||||
}
|
||||
|
||||
public static void counterWithMutableInteger(Map<String, MutableInteger> counterMap) {
|
||||
for (String country : COUNTRY_NAMES) {
|
||||
MutableInteger oldValue = counterMap.get(country);
|
||||
if (oldValue != null) {
|
||||
oldValue.increment();
|
||||
} else {
|
||||
counterMap.put(country, new MutableInteger(1));
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
public static void counterWithPrimitiveArray(Map<String, int[]> counterMap) {
|
||||
for (String country : COUNTRY_NAMES) {
|
||||
int[] oldCounter = counterMap.get(country);
|
||||
if (oldCounter != null) {
|
||||
oldCounter[0] += 1;
|
||||
} else {
|
||||
counterMap.put(country, new int[] { 1 });
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
}
|
||||
Loading…
Reference in New Issue