Merge branch 'master' of https://github.com/JonCook/tutorials

core-java-modules/core-java-lang-2/.gitignore

@@ -0,0 +1,25 @@
+*.class
+
+0.*
+
+#folders#
+/target
+/neoDb*
+/data
+/src/main/webapp/WEB-INF/classes
+*/META-INF/*
+.resourceCache
+
+# Packaged files #
+*.jar
+*.war
+*.ear
+
+# Files generated by integration tests
+backup-pom.xml
+/bin/
+/temp
+
+#IntelliJ specific
+.idea/
+*.iml

core-java-modules/core-java-lang-2/README.md

@@ -0,0 +1,8 @@
+## Core Java Lang (Part 2)
+
+This module contains articles about core features in the Java language
+
+### Relevant Articles: 
+- [Java Primitives versus Objects](https://www.baeldung.com/java-primitives-vs-objects)
+- [Command-Line Arguments in Java](https://www.baeldung.com/java-command-line-arguments)
+- [[<-- Prev]](/core-java-modules/core-java-lang)

core-java-modules/core-java-lang-2/pom.xml

@@ -0,0 +1,49 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-lang-2</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <name>core-java-lang-2</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-core</artifactId>
+            <version>${jmh-core.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-annprocess</artifactId>
+            <version>${jmh-generator.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.openjdk.jmh</groupId>
+            <artifactId>jmh-generator-bytecode</artifactId>
+            <version>${jmh-generator.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-lang-2</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+    </build>
+
+    <properties>
+        <jmh-core.version>1.19</jmh-core.version>
+        <jmh-generator.version>1.19</jmh-generator.version>
+    </properties>
+
+</project>

core-java-modules/core-java-lang-2/src/main/java/com/baeldung/commandlinearguments/CliExample.java

@@ -0,0 +1,12 @@
+package com.baeldung.commandlinearguments;
+
+public class CliExample {
+
+    public static void main(String[] args) {
+        System.out.println("Argument count: " + args.length);
+        for (int i = 0; i < args.length; i++) {
+            System.out.println("Argument " + i + ": " + args[i]);
+        }
+    }
+
+}

core-java-modules/core-java-lang-2/src/main/java/com/baeldung/commandlinearguments/CliExampleWithVarargs.java

@@ -0,0 +1,12 @@
+package com.baeldung.commandlinearguments;
+
+public class CliExampleWithVarargs {
+
+    public static void main(String... args) {
+        System.out.println("Argument count: " + args.length);
+        for (int i = 0; i < args.length; i++) {
+            System.out.println("Argument " + i + ": " + args[i]);
+        }
+    }
+
+}

core-java-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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-modules/core-java-lang-2/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();
+    }
+
+
+}