Java Primitives versus Objects (#4946)

* Add code for the article 'Java Primitives versus Objects'

* Use JMH for benchmarking the primitive and wrapper classes

* Uncomment the benchmarks and remove unused class

* Add Long/long to the benchmark

* Remove assertions from the benchmarks

* Add the java docs

core-java-8/src/main/java/com/baeldung/primitive/BenchmarkRunner.java

@@ -0,0 +1,23 @@
+package com.baeldung.primitive;
+
+public class BenchmarkRunner {
+
+    public static void main(String[] args) throws Exception {
+        new IntPrimitiveLookup().run();
+        new IntegerWrapperLookup().run();
+        new FloatPrimitiveLookup().run();
+        new FloatWrapperLookup().run();
+        new DoublePrimitiveLookup().run();
+        new DoubleWrapperLookup().run();
+        new ShortPrimitiveLookup().run();
+        new ShortWrapperLookup().run();
+        new BooleanPrimitiveLookup().run();
+        new BooleanWrapperLookup().run();
+        new CharPrimitiveLookup().run();
+        new CharacterWrapperLookup().run();
+        new BytePrimitiveLookup().run();
+        new ByteWrapperLookup().run();
+        new LongPrimitiveLookup().run();
+        new LongWrapperLookup().run();
+    }
+}

core-java-8/src/main/java/com/baeldung/primitive/BooleanPrimitiveLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class BooleanPrimitiveLookup extends Lookup {
+
+    private boolean[] elements;
+    private final boolean pivot = false;
+
+    @Setup
+    @Override
+    public void prepare() {
+        elements = new boolean[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = true;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return BooleanPrimitiveLookup.class.getSimpleName();
+    }
+
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/BooleanWrapperLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class BooleanWrapperLookup extends Lookup {
+    private Boolean[] elements;
+    private final boolean pivot = false;
+
+    @Override
+    @Setup
+    public void prepare() {
+        elements = new Boolean[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = true;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Boolean pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return BooleanWrapperLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/BytePrimitiveLookup.java

@@ -0,0 +1,46 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class BytePrimitiveLookup extends Lookup {
+
+    private byte[] elements;
+    private final byte pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        byte common = 1;
+        elements = new byte[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return BytePrimitiveLookup.class.getSimpleName();
+    }
+
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/ByteWrapperLookup.java

@@ -0,0 +1,46 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class ByteWrapperLookup extends Lookup {
+    private Byte[] elements;
+    private final byte pivot = 2;
+
+    @Override
+    @Setup
+    public void prepare() {
+        byte common = 1;
+        elements = new Byte[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Byte pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return ByteWrapperLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/CharPrimitiveLookup.java

@@ -0,0 +1,46 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class CharPrimitiveLookup extends Lookup {
+
+    private char[] elements;
+    private final char pivot = 'b';
+
+    @Setup
+    @Override
+    public void prepare() {
+        char common = 'a';
+        elements = new char[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return CharPrimitiveLookup.class.getSimpleName();
+    }
+
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/CharacterWrapperLookup.java

@@ -0,0 +1,46 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class CharacterWrapperLookup extends Lookup {
+    private Character[] elements;
+    private final char pivot = 'b';
+
+    @Override
+    @Setup
+    public void prepare() {
+        char common = 'a';
+        elements = new Character[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Character pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return CharacterWrapperLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/DoublePrimitiveLookup.java

@@ -0,0 +1,42 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class DoublePrimitiveLookup extends Lookup {
+    private double[] elements;
+    private final double pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        double common = 1;
+        elements = new double[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return DoublePrimitiveLookup.class.getSimpleName();
+    }
+}

core-java-8/src/main/java/com/baeldung/primitive/DoubleWrapperLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class DoubleWrapperLookup extends Lookup {
+    private Double[] elements;
+    private final double pivot = 2d;
+
+    @Override
+    @Setup
+    public void prepare() {
+        double common = 1;
+        elements = new Double[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Double pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return DoubleWrapperLookup.class.getSimpleName();
+    }
+
+}

core-java-8/src/main/java/com/baeldung/primitive/FloatPrimitiveLookup.java

@@ -0,0 +1,42 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class FloatPrimitiveLookup extends Lookup {
+    private float[] elements;
+    private final float pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        int common = 1;
+        elements = new float[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return FloatPrimitiveLookup.class.getSimpleName();
+    }
+}

core-java-8/src/main/java/com/baeldung/primitive/FloatWrapperLookup.java

@@ -0,0 +1,43 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class FloatWrapperLookup extends Lookup {
+    private Float[] elements;
+    private final float pivot = 2;
+
+    @Override
+    @Setup
+    public void prepare() {
+        float common = 1;
+        elements = new Float[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Float pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return FloatWrapperLookup.class.getSimpleName();
+    }
+}

core-java-8/src/main/java/com/baeldung/primitive/IntPrimitiveLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class IntPrimitiveLookup extends Lookup {
+
+    private int[] elements;
+    private final int pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        int common = 1;
+        elements = new int[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return IntPrimitiveLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/IntegerWrapperLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class IntegerWrapperLookup extends Lookup {
+    private Integer[] elements;
+    private final int pivot = 2;
+
+    @Override
+    @Setup
+    public void prepare() {
+        int common = 1;
+        elements = new Integer[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Integer pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return IntegerWrapperLookup.class.getSimpleName();
+    }
+
+}

core-java-8/src/main/java/com/baeldung/primitive/LongPrimitiveLookup.java

@@ -0,0 +1,42 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class LongPrimitiveLookup extends Lookup {
+    private long[] elements;
+    private final long pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        long common = 1;
+        elements = new long[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return LongPrimitiveLookup.class.getSimpleName();
+    }
+}

core-java-8/src/main/java/com/baeldung/primitive/LongWrapperLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class LongWrapperLookup extends Lookup{
+    private Long[] elements;
+    private final long pivot = 2;
+
+    @Override
+    @Setup
+    public void prepare() {
+        long common = 1;
+        elements = new Long[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Long pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return LongWrapperLookup.class.getSimpleName();
+    }
+
+}

core-java-8/src/main/java/com/baeldung/primitive/Lookup.java

@@ -0,0 +1,56 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.results.RunResult;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.RunnerException;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+import java.util.Collection;
+
+/**
+ * An abstract class that is to be extended by the classes that
+ * perform lookup in the arrays either of Java primitive types or their wrappers.
+ */
+public abstract class Lookup {
+    /**
+     * the array size
+     */
+    final protected int s = 50000000;
+
+    /**
+     * Initialize the array: fill in the array with the same
+     * elements except for the last one.
+     */
+    abstract public void prepare();
+
+    /**
+     * Free the array's reference.
+     */
+    abstract public void clean();
+
+    /**
+     * Find the position of the element that is different from the others.
+     * By construction, it is the last array element.
+     *
+     * @return array's last element index
+     */
+    abstract public int findPosition();
+
+    /**
+     * Get the name of the class that extends this one. It is needed in order
+     * to set up the benchmark.
+     *
+     * @return
+     */
+    abstract public String getSimpleClassName();
+
+    Collection<RunResult> run() throws RunnerException {
+        Options opt = new OptionsBuilder()
+                .include(getSimpleClassName())
+                .forks(1)
+                .build();
+        return new Runner(opt).run();
+    }
+
+}

core-java-8/src/main/java/com/baeldung/primitive/ShortPrimitiveLookup.java

@@ -0,0 +1,45 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class ShortPrimitiveLookup extends Lookup {
+
+    private short[] elements;
+    private final short pivot = 2;
+
+    @Setup
+    @Override
+    public void prepare() {
+        short common = 1;
+        elements = new short[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @TearDown
+    @Override
+    public void clean() {
+        elements = null;
+    }
+
+
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        while (pivot != elements[index]) {
+            index++;
+        }
+        return index;
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return ShortPrimitiveLookup.class.getSimpleName();
+    }
+
+
+}

core-java-8/src/main/java/com/baeldung/primitive/ShortWrapperLookup.java

@@ -0,0 +1,46 @@
+package com.baeldung.primitive;
+
+import org.openjdk.jmh.annotations.*;
+
+@State(Scope.Thread)
+public class ShortWrapperLookup extends Lookup {
+    private Short[] elements;
+    private final short pivot = 2;
+
+    @Override
+    @Setup
+    public void prepare() {
+        short common = 1;
+        elements = new Short[s];
+        for (int i = 0; i < s - 1; i++) {
+            elements[i] = common;
+        }
+        elements[s - 1] = pivot;
+    }
+
+    @Override
+    @TearDown
+    public void clean() {
+        elements = null;
+    }
+
+    @Override
+    @Benchmark
+    @BenchmarkMode(Mode.AverageTime)
+    public int findPosition() {
+        int index = 0;
+        Short pivotWrapper = pivot;
+        while (!pivotWrapper.equals(elements[index])) {
+            index++;
+        }
+        return index;
+
+    }
+
+    @Override
+    public String getSimpleClassName() {
+        return ShortWrapperLookup.class.getSimpleName();
+    }
+
+
+}

out/production/main/com/baeldung/.gitignore

@@ -0,0 +1,13 @@
+*.class
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+
+# Packaged files #
+*.jar
+*.war
+*.ear

out/production/main/com/baeldung/README.md

@@ -0,0 +1,2 @@
+### Relevant Articles:
+- [SHA-256 Hashing in Java](http://www.baeldung.com/sha-256-hashing-java)

out/production/main/com/baeldung/enums/README.md

@@ -0,0 +1,2 @@
+### Relevant Articles:
+- [A Guide to Java Enums](http://www.baeldung.com/a-guide-to-java-enums)

out/production/main/com/baeldung/networking/README.md

@@ -0,0 +1,5 @@
+### Relevant Articles:
+- [A Guide To UDP In Java](http://www.baeldung.com/udp-in-java)
+- [A Guide To HTTP Cookies In Java](http://www.baeldung.com/cookies-java)
+- [A Guide to the Java URL](http://www.baeldung.com/java-url)
+- [Working with Network Interfaces in Java](http://www.baeldung.com/java-network-interfaces)

out/production/main/com/baeldung/objectsize/MANIFEST.MF

@@ -0,0 +1 @@
+Premain-class: com.baeldung.objectsize.InstrumentationAgent

out/production/main/com/baeldung/printscreen/README.md

@@ -0,0 +1,2 @@
+### Relevant Articles:
+- [How to Print Screen in Java](http://www.baeldung.com/print-screen-in-java)

out/production/main/javac-args/arguments

@@ -0,0 +1,2 @@
+-d javac-target -verbose
+com/baeldung/javac/Data.java

out/production/main/javac-args/options

@@ -0,0 +1,2 @@
+-d javac-target
+-verbose

out/production/main/javac-args/types

@@ -0,0 +1 @@
+com/baeldung/javac/Data.java

out/production/main/javac-args/xlint-ops

@@ -0,0 +1,3 @@
+-d javac-target
+-Xlint:rawtypes,unchecked,static,cast,serial,fallthrough
+com/baeldung/javac/Data.java

out/production/main/log4j.properties

@@ -0,0 +1,9 @@
+# Set root logger level to DEBUG and its only appender to A1.
+log4j.rootLogger=DEBUG, A1
+
+# A1 is set to be a ConsoleAppender.
+log4j.appender.A1=org.apache.log4j.ConsoleAppender
+
+# A1 uses PatternLayout.
+log4j.appender.A1.layout=org.apache.log4j.PatternLayout
+log4j.appender.A1.layout.ConversionPattern=%-4r [%t] %-5p %c %x - %m%n

out/production/main1/com/baeldung/datetime/README.md

@@ -0,0 +1,2 @@
+### Relevant Articles:
+- [Introduction to the Java 8 Date/Time API](http://www.baeldung.com/java-8-date-time-intro)

out/test/test/com/baeldung/hexToAscii/README.md

@@ -0,0 +1,2 @@
+### Relevant Articles:
+- [Convert Hex to ASCII in Java](http://www.baeldung.com/java-convert-hex-to-ascii)

out/test/test/com/baeldung/java/conversion/README.md

@@ -0,0 +1,2 @@
+Relevant Articles:
+- [Java String Conversions](http://www.baeldung.com/java-string-conversions)