Merge branch 'master' into BAEL-2313-String-to-byte-array

.travis.yml

@@ -4,7 +4,7 @@ before_install:
   - echo "MAVEN_OPTS='-Xmx2048M -Xss128M -XX:+CMSClassUnloadingEnabled -XX:+UseG1GC -XX:-UseGCOverheadLimit'" > ~/.mavenrc
 
 install: skip
-script: travis_wait 60 mvn -q install -Pdefault-first,default-second
+script: travis_wait 60 mvn -q install -Pdefault-first,default-second -Dgib.enabled=true
 
 sudo: required
 

JGit/src/main/java/com/baeldung/jgit/porcelain/Log.java

@@ -28,14 +28,14 @@ public class Log {
                 System.out.println("Had " + count + " commits overall on current branch");
 
                 logs = git.log()
-                        .add(repository.resolve("remotes/origin/testbranch"))
+                        .add(repository.resolve(git.getRepository().getFullBranch()))
                         .call();
                 count = 0;
                 for (RevCommit rev : logs) {
                     System.out.println("Commit: " + rev /* + ", name: " + rev.getName() + ", id: " + rev.getId().getName() */);
                     count++;
                 }
-                System.out.println("Had " + count + " commits overall on test-branch");
+                System.out.println("Had " + count + " commits overall on "+git.getRepository().getFullBranch());
 
                 logs = git.log()
                         .all()

JGit/src/test/java/com/baeldung/jgit/JGitBugIntegrationTest.java

@@ -1,3 +1,5 @@
+package com.baeldung.jgit;
+
 import com.baeldung.jgit.helper.Helper;
 import org.eclipse.jgit.lib.ObjectLoader;
 import org.eclipse.jgit.lib.ObjectReader;

algorithms-genetic/pom.xml

@@ -1,9 +1,9 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>algorithms-genetic</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>algorithms-genetic</name>
     
     <parent>
         <groupId>com.baeldung</groupId>
@@ -61,4 +61,5 @@
         <commons-codec.version>1.11</commons-codec.version>
     </properties>
 
+    
 </project>

algorithms-miscellaneous-1/pom.xml

@@ -1,9 +1,9 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>algorithms-miscellaneous-1</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>algorithms-miscellaneous-1</name>
     
     <parent>
         <groupId>com.baeldung</groupId>
@@ -17,6 +17,11 @@
             <artifactId>commons-math3</artifactId>
             <version>${commons-math3.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.google.guava</groupId>
+            <artifactId>guava</artifactId>
+            <version>${guava.version}</version>
+        </dependency>
         <dependency>
             <groupId>commons-codec</groupId>
             <artifactId>commons-codec</artifactId>
@@ -73,6 +78,7 @@
         <commons-math3.version>3.6.1</commons-math3.version>
         <org.assertj.core.version>3.9.0</org.assertj.core.version>
         <commons-codec.version>1.11</commons-codec.version>
+        <guava.version>25.1-jre</guava.version>
     </properties>
 
 </project>

algorithms-miscellaneous-1/src/main/java/com/baeldung/algorithms/factorial/Factorial.java

@@ -0,0 +1,63 @@
+package com.baeldung.algorithms.factorial;
+
+import java.math.BigInteger;
+import java.util.stream.LongStream;
+
+import org.apache.commons.math3.util.CombinatoricsUtils;
+
+import com.google.common.math.BigIntegerMath;
+
+public class Factorial {
+
+    public long factorialUsingForLoop(int n) {
+        long fact = 1;
+        for (int i = 2; i <= n; i++) {
+            fact = fact * i;
+        }
+        return fact;
+    }
+
+    public long factorialUsingStreams(int n) {
+        return LongStream.rangeClosed(1, n)
+            .reduce(1, (long x, long y) -> x * y);
+    }
+
+    public long factorialUsingRecursion(int n) {
+        if (n <= 2) {
+            return n;
+        }
+        return n * factorialUsingRecursion(n - 1);
+    }
+
+    private Long[] factorials = new Long[20];
+
+    public long factorialUsingMemoize(int n) {
+
+        if (factorials[n] != null) {
+            return factorials[n];
+        }
+
+        if (n <= 2) {
+            return n;
+        }
+        long nthValue = n * factorialUsingMemoize(n - 1);
+        factorials[n] = nthValue;
+        return nthValue;
+    }
+
+    public BigInteger factorialHavingLargeResult(int n) {
+        BigInteger result = BigInteger.ONE;
+        for (int i = 2; i <= n; i++)
+            result = result.multiply(BigInteger.valueOf(i));
+        return result;
+    }
+
+    public long factorialUsingApacheCommons(int n) {
+        return CombinatoricsUtils.factorial(n);
+    }
+
+    public BigInteger factorialUsingGuava(int n) {
+        return BigIntegerMath.factorial(n);
+    }
+
+}

algorithms-miscellaneous-1/src/main/java/com/baeldung/algorithms/string/LongestSubstringNonRepeatingCharacters.java

@@ -0,0 +1,54 @@
+package com.baeldung.algorithms.string;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+public class LongestSubstringNonRepeatingCharacters {
+
+    public static String getUniqueCharacterSubstringBruteForce(String input) {
+        String output = "";
+        for (int start = 0; start < input.length(); start++) {
+            Set<Character> visited = new HashSet<>();
+            int end = start;
+            for (; end < input.length(); end++) {
+                char currChar = input.charAt(end);
+                if (visited.contains(currChar)) {
+                    break;
+                } else {
+                    visited.add(currChar);
+                }
+            }
+            if (output.length() < end - start + 1) {
+                output = input.substring(start, end);
+            }
+        }
+        return output;
+    }
+
+    public static String getUniqueCharacterSubstring(String input) {
+        Map<Character, Integer> visited = new HashMap<>();
+        String output = "";
+        for (int start = 0, end = 0; end < input.length(); end++) {
+            char currChar = input.charAt(end);
+            if (visited.containsKey(currChar)) {
+                start = Math.max(visited.get(currChar) + 1, start);
+            }
+            if (output.length() < end - start + 1) {
+                output = input.substring(start, end + 1);
+            }
+            visited.put(currChar, end);
+        }
+        return output;
+    }
+
+    public static void main(String[] args) {
+        if(args.length > 0) {
+            System.out.println(getUniqueCharacterSubstring(args[0]));
+        } else {
+            System.err.println("This program expects command-line input. Please try again!");
+        }
+    }
+
+}

algorithms-miscellaneous-1/src/main/java/com/baeldung/algorithms/string/SubstringPalindrome.java

@@ -0,0 +1,90 @@
+package com.baeldung.algorithms.string;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class SubstringPalindrome {
+
+    public Set<String> findAllPalindromesUsingCenter(String input) {
+        final Set<String> palindromes = new HashSet<>();
+        if (input == null || input.isEmpty()) {
+            return palindromes;
+        }
+        if (input.length() == 1) {
+            palindromes.add(input);
+            return palindromes;
+        }
+        for (int i = 0; i < input.length(); i++) {
+            palindromes.addAll(findPalindromes(input, i, i + 1));
+            palindromes.addAll(findPalindromes(input, i, i));
+        }
+        return palindromes;
+    }
+
+    private Set<String> findPalindromes(String input, int low, int high) {
+        Set<String> result = new HashSet<>();
+        while (low >= 0 && high < input.length() && input.charAt(low) == input.charAt(high)) {
+            result.add(input.substring(low, high + 1));
+            low--;
+            high++;
+        }
+        return result;
+    }
+
+    public Set<String> findAllPalindromesUsingBruteForceApproach(String input) {
+        Set<String> palindromes = new HashSet<>();
+        if (input == null || input.isEmpty()) {
+            return palindromes;
+        }
+        if (input.length() == 1) {
+            palindromes.add(input);
+            return palindromes;
+        }
+        for (int i = 0; i < input.length(); i++) {
+            for (int j = i + 1; j <= input.length(); j++)
+                if (isPalindrome(input.substring(i, j))) {
+                    palindromes.add(input.substring(i, j));
+                }
+        }
+        return palindromes;
+    }
+
+    private boolean isPalindrome(String input) {
+        StringBuilder plain = new StringBuilder(input);
+        StringBuilder reverse = plain.reverse();
+        return (reverse.toString()).equals(input);
+    }
+
+    public Set<String> findAllPalindromesUsingManachersAlgorithm(String input) {
+        Set<String> palindromes = new HashSet<>();
+        String formattedInput = "@" + input + "#";
+        char inputCharArr[] = formattedInput.toCharArray();
+        int max;
+        int radius[][] = new int[2][input.length() + 1];
+        for (int j = 0; j <= 1; j++) {
+            radius[j][0] = max = 0;
+            int i = 1;
+            while (i <= input.length()) {
+                palindromes.add(Character.toString(inputCharArr[i]));
+                while (inputCharArr[i - max - 1] == inputCharArr[i + j + max])
+                    max++;
+                radius[j][i] = max;
+                int k = 1;
+                while ((radius[j][i - k] != max - k) && (k < max)) {
+                    radius[j][i + k] = Math.min(radius[j][i - k], max - k);
+                    k++;
+                }
+                max = Math.max(max - k, 0);
+                i += k;
+            }
+        }
+        for (int i = 1; i <= input.length(); i++) {
+            for (int j = 0; j <= 1; j++) {
+                for (max = radius[j][i]; max > 0; max--) {
+                    palindromes.add(input.substring(i - max - 1, max + j + i - 1));
+                }
+            }
+        }
+        return palindromes;
+    }
+}

algorithms-miscellaneous-1/src/test/java/com/baeldung/algorithms/factorial/FactorialUnitTest.java

@@ -0,0 +1,72 @@
+package com.baeldung.algorithms.factorial;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.math.BigInteger;
+
+import org.junit.Before;
+import org.junit.Test;
+
+public class FactorialUnitTest {
+
+    Factorial factorial;
+
+    @Before
+    public void setup() {
+        factorial = new Factorial();
+    }
+
+    @Test
+    public void whenCalculatingFactorialUsingForLoop_thenCorrect() {
+        int n = 5;
+
+        assertThat(factorial.factorialUsingForLoop(n)).isEqualTo(120);
+    }
+
+    @Test
+    public void whenCalculatingFactorialUsingStreams_thenCorrect() {
+        int n = 5;
+
+        assertThat(factorial.factorialUsingStreams(n)).isEqualTo(120);
+    }
+
+    @Test
+    public void whenCalculatingFactorialUsingRecursion_thenCorrect() {
+        int n = 5;
+
+        assertThat(factorial.factorialUsingRecursion(n)).isEqualTo(120);
+    }
+
+    @Test
+    public void whenCalculatingFactorialUsingMemoize_thenCorrect() {
+        int n = 5;
+
+        assertThat(factorial.factorialUsingMemoize(n)).isEqualTo(120);
+
+        n = 6;
+
+        assertThat(factorial.factorialUsingMemoize(n)).isEqualTo(720);
+    }
+
+    @Test
+    public void whenCalculatingFactorialHavingLargeResult_thenCorrect() {
+        int n = 22;
+
+        assertThat(factorial.factorialHavingLargeResult(n)).isEqualTo(new BigInteger("1124000727777607680000"));
+    }
+
+    @Test
+    public void whenCalculatingFactorialUsingApacheCommons_thenCorrect() {
+        int n = 5;
+
+        assertThat(factorial.factorialUsingApacheCommons(n)).isEqualTo(120);
+    }
+
+    @Test
+    public void whenCalculatingFactorialUsingGuava_thenCorrect() {
+        int n = 22;
+
+        assertThat(factorial.factorialUsingGuava(n)).isEqualTo(new BigInteger("1124000727777607680000"));
+    }
+
+}

algorithms-miscellaneous-1/src/test/java/com/baeldung/algorithms/string/LongestSubstringNonRepeatingCharactersUnitTest.java

@@ -0,0 +1,31 @@
+package com.baeldung.algorithms.string;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static com.baeldung.algorithms.string.LongestSubstringNonRepeatingCharacters.getUniqueCharacterSubstring;
+import static com.baeldung.algorithms.string.LongestSubstringNonRepeatingCharacters.getUniqueCharacterSubstringBruteForce;
+
+public class LongestSubstringNonRepeatingCharactersUnitTest {
+
+    @Test
+    void givenString_whenGetUniqueCharacterSubstringBruteForceCalled_thenResultFoundAsExpectedUnitTest() {
+        assertEquals("", getUniqueCharacterSubstringBruteForce(""));
+        assertEquals("A", getUniqueCharacterSubstringBruteForce("A"));
+        assertEquals("ABCDEF", getUniqueCharacterSubstringBruteForce("AABCDEF"));
+        assertEquals("ABCDEF", getUniqueCharacterSubstringBruteForce("ABCDEFF"));
+        assertEquals("NGISAWE", getUniqueCharacterSubstringBruteForce("CODINGISAWESOME"));
+        assertEquals("be coding", getUniqueCharacterSubstringBruteForce("always be coding"));
+    }
+
+    @Test
+    void givenString_whenGetUniqueCharacterSubstringCalled_thenResultFoundAsExpectedUnitTest() {
+        assertEquals("", getUniqueCharacterSubstring(""));
+        assertEquals("A", getUniqueCharacterSubstring("A"));
+        assertEquals("ABCDEF", getUniqueCharacterSubstring("AABCDEF"));
+        assertEquals("ABCDEF", getUniqueCharacterSubstring("ABCDEFF"));
+        assertEquals("NGISAWE", getUniqueCharacterSubstring("CODINGISAWESOME"));
+        assertEquals("be coding", getUniqueCharacterSubstring("always be coding"));
+    }
+
+}

algorithms-miscellaneous-1/src/test/java/com/baeldung/algorithms/string/SubstringPalindromeUnitTest.java

@@ -0,0 +1,83 @@
+package com.baeldung.algorithms.string;
+
+import static org.junit.Assert.assertEquals;
+import java.util.HashSet;
+import java.util.Set;
+import org.junit.Test;
+
+public class SubstringPalindromeUnitTest {
+
+    private static final String INPUT_BUBBLE = "bubble";
+    private static final String INPUT_CIVIC = "civic";
+    private static final String INPUT_INDEED = "indeed";
+    private static final String INPUT_ABABAC = "ababac";
+
+    Set<String> EXPECTED_PALINDROME_BUBBLE = new HashSet<String>() {
+        {
+            add("b");
+            add("u");
+            add("l");
+            add("e");
+            add("bb");
+            add("bub");
+        }
+    };
+
+    Set<String> EXPECTED_PALINDROME_CIVIC = new HashSet<String>() {
+        {
+            add("civic");
+            add("ivi");
+            add("i");
+            add("c");
+            add("v");
+        }
+    };
+
+    Set<String> EXPECTED_PALINDROME_INDEED = new HashSet<String>() {
+        {
+            add("i");
+            add("n");
+            add("d");
+            add("e");
+            add("ee");
+            add("deed");
+        }
+    };
+
+    Set<String> EXPECTED_PALINDROME_ABABAC = new HashSet<String>() {
+        {
+            add("a");
+            add("b");
+            add("c");
+            add("aba");
+            add("bab");
+            add("ababa");
+        }
+    };
+
+    private SubstringPalindrome palindrome = new SubstringPalindrome();
+
+    @Test
+    public void whenUsingManachersAlgorithm_thenFindsAllPalindromes() {
+        assertEquals(EXPECTED_PALINDROME_BUBBLE, palindrome.findAllPalindromesUsingManachersAlgorithm(INPUT_BUBBLE));
+        assertEquals(EXPECTED_PALINDROME_INDEED, palindrome.findAllPalindromesUsingManachersAlgorithm(INPUT_INDEED));
+        assertEquals(EXPECTED_PALINDROME_CIVIC, palindrome.findAllPalindromesUsingManachersAlgorithm(INPUT_CIVIC));
+        assertEquals(EXPECTED_PALINDROME_ABABAC, palindrome.findAllPalindromesUsingManachersAlgorithm(INPUT_ABABAC));
+    }
+
+    @Test
+    public void whenUsingCenterApproach_thenFindsAllPalindromes() {
+        assertEquals(EXPECTED_PALINDROME_BUBBLE, palindrome.findAllPalindromesUsingCenter(INPUT_BUBBLE));
+        assertEquals(EXPECTED_PALINDROME_INDEED, palindrome.findAllPalindromesUsingCenter(INPUT_INDEED));
+        assertEquals(EXPECTED_PALINDROME_CIVIC, palindrome.findAllPalindromesUsingCenter(INPUT_CIVIC));
+        assertEquals(EXPECTED_PALINDROME_ABABAC, palindrome.findAllPalindromesUsingCenter(INPUT_ABABAC));
+    }
+
+    @Test
+    public void whenUsingBruteForceApproach_thenFindsAllPalindromes() {
+        assertEquals(EXPECTED_PALINDROME_BUBBLE, palindrome.findAllPalindromesUsingBruteForceApproach(INPUT_BUBBLE));
+        assertEquals(EXPECTED_PALINDROME_INDEED, palindrome.findAllPalindromesUsingBruteForceApproach(INPUT_INDEED));
+        assertEquals(EXPECTED_PALINDROME_CIVIC, palindrome.findAllPalindromesUsingBruteForceApproach(INPUT_CIVIC));
+        assertEquals(EXPECTED_PALINDROME_ABABAC, palindrome.findAllPalindromesUsingBruteForceApproach(INPUT_ABABAC));
+    }
+}

algorithms-miscellaneous-2/README.md

@@ -17,3 +17,4 @@
 - [Round Up to the Nearest Hundred](https://www.baeldung.com/java-round-up-nearest-hundred)
 - [Calculate Percentage in Java](https://www.baeldung.com/java-calculate-percentage)
 - [Converting Between Byte Arrays and Hexadecimal Strings in Java](https://www.baeldung.com/java-byte-arrays-hex-strings)
+- [Convert Latitude and Longitude to a 2D Point in Java](https://www.baeldung.com/java-convert-latitude-longitude)

algorithms-miscellaneous-2/pom.xml

@@ -1,9 +1,9 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>algorithms-miscellaneous-2</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>algorithms-miscellaneous-2</name>
 
     <parent>
         <groupId>com.baeldung</groupId>
@@ -33,6 +33,11 @@
             <artifactId>jgrapht-core</artifactId>
             <version>${org.jgrapht.core.version}</version>
         </dependency>
+        <dependency>
+        	<groupId>org.jgrapht</groupId>
+        	<artifactId>jgrapht-ext</artifactId>
+        	<version>${org.jgrapht.ext.version}</version>
+        </dependency>
         <dependency>
             <groupId>pl.allegro.finance</groupId>
             <artifactId>tradukisto</artifactId>
@@ -83,6 +88,7 @@
         <commons-math3.version>3.6.1</commons-math3.version>
         <tradukisto.version>1.0.1</tradukisto.version>
         <org.jgrapht.core.version>1.0.1</org.jgrapht.core.version>
+        <org.jgrapht.ext.version>1.0.1</org.jgrapht.ext.version>
         <org.assertj.core.version>3.9.0</org.assertj.core.version>
         <commons-codec.version>1.11</commons-codec.version>
     </properties>

algorithms-miscellaneous-2/src/test/java/com/baeldung/jgrapht/GraphImageGenerationUnitTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.jgrapht;
+
+import static org.junit.Assert.assertTrue;
+import java.awt.Color;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.io.IOException;
+import javax.imageio.ImageIO;
+import org.jgrapht.ext.JGraphXAdapter;
+import org.jgrapht.graph.DefaultDirectedGraph;
+import org.jgrapht.graph.DefaultEdge;
+import org.junit.Before;
+import org.junit.Test;
+import com.mxgraph.layout.mxCircleLayout;
+import com.mxgraph.layout.mxIGraphLayout;
+import com.mxgraph.util.mxCellRenderer;
+
+public class GraphImageGenerationUnitTest {
+    static DefaultDirectedGraph<String, DefaultEdge> g;
+
+    @Before
+    public void createGraph() throws IOException {
+        File imgFile = new File("src/test/resources/graph.png");
+        imgFile.createNewFile();
+        g = new DefaultDirectedGraph<String, DefaultEdge>(DefaultEdge.class);
+        String x1 = "x1";
+        String x2 = "x2";
+        String x3 = "x3";
+        g.addVertex(x1);
+        g.addVertex(x2);
+        g.addVertex(x3);
+        g.addEdge(x1, x2);
+        g.addEdge(x2, x3);
+        g.addEdge(x3, x1);
+    }
+
+    @Test
+    public void givenAdaptedGraph_whenWriteBufferedImage_ThenFileShouldExist() throws IOException {
+        JGraphXAdapter<String, DefaultEdge> graphAdapter = new JGraphXAdapter<String, DefaultEdge>(g);
+        mxIGraphLayout layout = new mxCircleLayout(graphAdapter);
+        layout.execute(graphAdapter.getDefaultParent());
+        File imgFile = new File("src/test/resources/graph.png");
+        BufferedImage image = mxCellRenderer.createBufferedImage(graphAdapter, null, 2, Color.WHITE, true, null);
+        ImageIO.write(image, "PNG", imgFile);
+        assertTrue(imgFile.exists());
+    }
+}

algorithms-sorting/README.md

@@ -4,4 +4,4 @@
 - [Merge Sort in Java](https://www.baeldung.com/java-merge-sort)
 - [Quicksort Algorithm Implementation in Java](https://www.baeldung.com/java-quicksort)
 - [Insertion Sort in Java](https://www.baeldung.com/java-insertion-sort)
-
+- [Heap Sort in Java](https://www.baeldung.com/java-heap-sort)

algorithms-sorting/pom.xml

@@ -1,9 +1,9 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>algorithms-sorting</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>algorithms-sorting</name>
 
     <parent>
         <groupId>com.baeldung</groupId>

algorithms-sorting/src/main/java/com/baeldung/algorithms/mergesort/MergeSort.java

@@ -34,7 +34,7 @@ public class MergeSort {
 
         while (i < left && j < right) {
 
-            if (l[i] < r[j])
+            if (l[i] <= r[j])
                 a[k++] = l[i++];
             else
                 a[k++] = r[j++];

annotations/annotation-processing/pom.xml

@@ -3,6 +3,7 @@
     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>annotation-processing</artifactId>
+    <name>annotation-processing</name>
     
     <parent>
         <groupId>com.baeldung</groupId>

annotations/annotation-user/pom.xml

@@ -3,6 +3,7 @@
     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>annotation-user</artifactId>
+    <name>annotation-user</name>
 
     <parent>
         <artifactId>annotations</artifactId>

annotations/pom.xml

@@ -4,6 +4,7 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>annotations</artifactId>
     <packaging>pom</packaging>
+    <name>annotations</name>
     
     <parent>
         <artifactId>parent-modules</artifactId>

apache-avro/pom.xml

@@ -3,10 +3,9 @@
          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>
-    <groupId>com.baeldung</groupId>
     <artifactId>apache-avro</artifactId>
     <version>0.0.1-SNAPSHOT</version>
-	<name>Apache Avro</name>
+	<name>apache-avro</name>
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

apache-bval/pom.xml

@@ -4,6 +4,7 @@
     <groupId>apache-bval</groupId>
     <artifactId>apache-bval</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>apache-bval</name>
     
     <parent>
         <groupId>com.baeldung</groupId>

apache-curator/pom.xml

@@ -4,6 +4,7 @@
     <artifactId>apache-curator</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
+	<name>apache-curator</name>
 
     <parent>
         <groupId>com.baeldung</groupId>

apache-cxf/cxf-aegis/pom.xml

@@ -2,6 +2,7 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-aegis</artifactId>
+	<name>cxf-aegis</name>
 	
     <parent>
         <groupId>com.baeldung</groupId>

apache-cxf/cxf-introduction/pom.xml

@@ -4,6 +4,7 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-introduction</artifactId>
+	<name>cxf-introduction</name>
 	
     <parent>
         <groupId>com.baeldung</groupId>

apache-cxf/cxf-jaxrs-implementation/pom.xml

@@ -4,6 +4,7 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-jaxrs-implementation</artifactId>
+	<name>cxf-jaxrs-implementation</name>
 	
     <parent>
         <groupId>com.baeldung</groupId>

apache-cxf/cxf-spring/pom.xml

@@ -3,6 +3,7 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>cxf-spring</artifactId>
     <packaging>war</packaging>
+	<name>cxf-spring</name>
 
     <parent>
         <groupId>com.baeldung</groupId>

apache-cxf/pom.xml

@@ -1,9 +1,9 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>apache-cxf</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>apache-cxf</name>
     <packaging>pom</packaging>
 
     <parent>

apache-cxf/sse-jaxrs/pom.xml

@@ -3,8 +3,8 @@
          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>sse-jaxrs</artifactId>
+    <name>sse-jaxrs</name>
     <packaging>pom</packaging>
 
     <parent>

apache-cxf/sse-jaxrs/sse-jaxrs-client/pom.xml

@@ -3,6 +3,8 @@
          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>sse-jaxrs-client</artifactId>
+    <name>sse-jaxrs-client</name>
     
     <parent>
         <groupId>com.baeldung</groupId>
@@ -10,8 +12,6 @@
         <version>0.0.1-SNAPSHOT</version>
     </parent>
 
-    <artifactId>sse-jaxrs-client</artifactId>
-
     <properties>
         <cxf-version>3.2.0</cxf-version>
     </properties>
@@ -21,7 +21,6 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>exec-maven-plugin</artifactId>
-                <version>1.6.0</version>
                 <executions>
                     <execution>
                         <id>singleEvent</id>

apache-cxf/sse-jaxrs/sse-jaxrs-server/pom.xml

@@ -3,6 +3,9 @@
          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>sse-jaxrs-server</artifactId>
+    <name>sse-jaxrs-server</name>
+    <packaging>war</packaging>
     
     <parent>
         <groupId>com.baeldung</groupId>
@@ -10,9 +13,6 @@
         <version>0.0.1-SNAPSHOT</version>
     </parent>
 
-    <artifactId>sse-jaxrs-server</artifactId>
-    <packaging>war</packaging>
-
     <properties>
         <liberty-maven-plugin.version>2.4.2</liberty-maven-plugin.version>
         <failOnMissingWebXml>false</failOnMissingWebXml>

apache-geode/pom.xml

@@ -3,10 +3,9 @@
          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>
-
-    <groupId>com.baeldung</groupId>
     <artifactId>apache-geode</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <name>apache-geode</name>
     
     <parent>
         <groupId>com.baeldung</groupId>

apache-opennlp/pom.xml

@@ -4,6 +4,7 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-opennlp</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <name>apache-opennlp</name>
     <packaging>jar</packaging>
 
     <parent>

apache-poi/pom.xml

@@ -1,9 +1,9 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>apache-poi</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>apache-poi</name>
 
     <parent>
         <groupId>com.baeldung</groupId>

apache-pulsar/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles: 
+
+- [Introduction to Apache Pulsar](https://www.baeldung.com/apache-pulsar)

apache-pulsar/pom.xml

@@ -3,8 +3,9 @@
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung.pulsar</groupId>
-  <artifactId>pulsar-java</artifactId>
+    <artifactId>apache-pulsar</artifactId>
     <version>0.0.1</version>
+    <name>apache-pulsar</name>
 
     <dependencies>
         <dependency>

apache-shiro/pom.xml

@@ -5,6 +5,7 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>apache-shiro</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <name>apache-shiro</name>
     
     <parent>
         <artifactId>parent-boot-1</artifactId>

apache-thrift/pom.xml

@@ -1,9 +1,9 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>apache-thrift</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>apache-thrift</name>
     <packaging>pom</packaging>
 
     <parent>

apache-tika/pom.xml

@@ -1,9 +1,9 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>apache-tika</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>apache-tika</name>
     
     <parent>
         <groupId>com.baeldung</groupId>

apache-zookeeper/pom.xml

@@ -1,9 +1,9 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>apache-zookeeper</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>apache-zookeeper</name>
     <packaging>jar</packaging>
 
     <parent>

asm/pom.xml

@@ -5,6 +5,7 @@
     <groupId>com.baeldung.examples</groupId>
     <artifactId>asm</artifactId>
     <version>1.0</version>
+    <name>asm</name>
     <packaging>jar</packaging>
 
     <parent>

atomix/pom.xml

@@ -4,6 +4,7 @@
     <groupId>com.atomix.io</groupId>
     <artifactId>atomix</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+    <name>atomix</name>
     
     <parent>
         <groupId>com.baeldung</groupId>

axon/pom.xml

@@ -3,6 +3,7 @@
     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>axon</artifactId>
+    <name>axon</name>
         
     <parent>
         <artifactId>parent-modules</artifactId>

cas/cas-server/pom.xml

@@ -3,8 +3,9 @@
     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>cas-server</artifactId>
-    <packaging>war</packaging>
     <version>1.0</version>
+    <name>cas-server</name>
+    <packaging>war</packaging>
 
     <parent>
         <artifactId>parent-boot-1</artifactId>

cdi/README.md

@@ -1,3 +1,5 @@
 ### Relevant Articles:
 - [CDI Interceptor vs Spring AspectJ](http://www.baeldung.com/cdi-interceptor-vs-spring-aspectj)
 - [An Introduction to CDI (Contexts and Dependency Injection) in Java](http://www.baeldung.com/java-ee-cdi)
+- [Introduction to the Event Notification Model in CDI 2.0](https://www.baeldung.com/cdi-event-notification)
+

cdi/pom.xml

@@ -2,9 +2,9 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>cdi</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <name>cdi</name>
     
     <parent>
         <groupId>com.baeldung</groupId>
@@ -14,6 +14,16 @@
     </parent>
 
     <dependencies>
+        <dependency>
+            <groupId>javax.enterprise</groupId>
+            <artifactId>cdi-api</artifactId>
+            <version>${cdi-api.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.jboss.weld.se</groupId>
+            <artifactId>weld-se-core</artifactId>
+            <version>${weld-se-core.version}</version>
+        </dependency>  
         <dependency>
             <groupId>org.hamcrest</groupId>
             <artifactId>hamcrest-core</artifactId>
@@ -42,11 +52,6 @@
             <artifactId>aspectjweaver</artifactId>
             <version>${aspectjweaver.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.jboss.weld.se</groupId>
-            <artifactId>weld-se-core</artifactId>
-            <version>${weld-se-core.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-test</artifactId>
@@ -54,13 +59,13 @@
             <scope>test</scope>
         </dependency>
     </dependencies>
-
     <properties>
-        <aspectjweaver.version>1.8.9</aspectjweaver.version>
+        <cdi-api.version>2.0.SP1</cdi-api.version>
-        <weld-se-core.version>2.4.1.Final</weld-se-core.version>
+        <weld-se-core.version>3.0.5.Final</weld-se-core.version>
+        <aspectjweaver.version>1.9.2</aspectjweaver.version>
         <hamcrest-core.version>1.3</hamcrest-core.version>
         <assertj-core.version>3.10.0</assertj-core.version>
         <junit.version>4.12</junit.version>
+        <spring.version>5.1.2.RELEASE</spring.version>
     </properties>
-
 </project>

cdi/src/main/java/com/baeldung/cdi2observers/application/BootstrappingApplication.java

@@ -0,0 +1,15 @@
+package com.baeldung.cdi.cdi2observers.application;
+
+import com.baeldung.cdi.cdi2observers.events.ExampleEvent;
+import javax.enterprise.inject.se.SeContainer;
+import javax.enterprise.inject.se.SeContainerInitializer;
+
+public class BootstrappingApplication {
+    
+    public static void main(String... args) {
+        SeContainerInitializer containerInitializer = SeContainerInitializer.newInstance();
+        try (SeContainer container = containerInitializer.initialize()) {
+            container.getBeanManager().fireEvent(new ExampleEvent("Welcome to Baeldung!"));
+        }
+    }
+}

cdi/src/main/java/com/baeldung/cdi2observers/events/ExampleEvent.java

@@ -0,0 +1,14 @@
+package com.baeldung.cdi.cdi2observers.events;
+
+public class ExampleEvent {
+    
+   private final String eventMessage;
+
+    public ExampleEvent(String eventMessage) {
+        this.eventMessage = eventMessage;
+    }
+    
+    public String getEventMessage() {
+        return eventMessage;
+    }
+}

cdi/src/main/java/com/baeldung/cdi2observers/events/ExampleEventSource.java

@@ -0,0 +1,14 @@
+package com.baeldung.cdi.cdi2observers.events;
+
+import javax.enterprise.event.Event;
+import javax.inject.Inject;
+
+public class ExampleEventSource {
+    
+    @Inject
+    Event<ExampleEvent> exampleEvent;
+    
+    public void fireEvent() {
+        exampleEvent.fireAsync(new ExampleEvent("Welcome to Baeldung!"));
+    }   
+}

cdi/src/main/java/com/baeldung/cdi2observers/observers/AnotherExampleEventObserver.java

@@ -0,0 +1,12 @@
+package com.baeldung.cdi.cdi2observers.observers;
+
+import com.baeldung.cdi.cdi2observers.events.ExampleEvent;
+import javax.annotation.Priority;
+import javax.enterprise.event.Observes;
+
+public class AnotherExampleEventObserver {
+    
+    public String onEvent(@Observes @Priority(2) ExampleEvent event) {
+        return event.getEventMessage();
+    }   
+}

cdi/src/main/java/com/baeldung/cdi2observers/observers/ExampleEventObserver.java

@@ -0,0 +1,13 @@
+package com.baeldung.cdi.cdi2observers.observers;
+
+import com.baeldung.cdi.cdi2observers.events.ExampleEvent;
+import com.baeldung.cdi.cdi2observers.services.TextService;
+import javax.annotation.Priority;
+import javax.enterprise.event.Observes;
+
+public class ExampleEventObserver {
+    
+    public String onEvent(@Observes @Priority(1) ExampleEvent event, TextService textService) {
+        return textService.parseText(event.getEventMessage());
+    } 
+}

cdi/src/main/java/com/baeldung/cdi2observers/services/TextService.java

@@ -0,0 +1,8 @@
+package com.baeldung.cdi.cdi2observers.services;
+
+public class TextService {
+
+    public String parseText(String text) {
+        return text.toUpperCase();
+    }
+}

cdi/src/test/java/com/baeldung/test/cdi2observers/tests/TextServiceUnitTest.java

@@ -0,0 +1,14 @@
+package com.baeldung.cdi.cdi2observers.tests;
+
+import com.baeldung.cdi.cdi2observers.services.TextService;
+import static org.assertj.core.api.Assertions.assertThat;
+import org.junit.Test;
+
+public class TextServiceUnitTest {
+
+    @Test
+    public void givenTextServiceInstance_whenCalledparseText_thenCorrect() {
+        TextService textService = new TextService();
+        assertThat(textService.parseText("Baeldung")).isEqualTo("BAELDUNG");
+    }
+}

core-groovy/pom.xml

@@ -4,6 +4,7 @@
     <modelVersion>4.0.0</modelVersion>
     <artifactId>core-groovy</artifactId>
     <version>1.0-SNAPSHOT</version>
+    <name>core-groovy</name>
     <packaging>jar</packaging>
 
     <parent>

core-java-10/README.md

@@ -4,3 +4,4 @@
 - [Java 10 LocalVariable Type-Inference](http://www.baeldung.com/java-10-local-variable-type-inference)
 - [Guide to Java 10](http://www.baeldung.com/java-10-overview)
 - [Copy a List to Another List in Java](http://www.baeldung.com/java-copy-list-to-another)
+- [Deep Dive Into the New Java JIT Compiler – Graal](https://www.baeldung.com/graal-java-jit-compiler)

core-java-11/src/main/java/com/baeldung/add

@@ -0,0 +1,12 @@
+#!/usr/local/bin/java --source 11
+
+import java.util.Arrays;
+
+public class Addition
+{
+    public static void main(String[] args) {
+        System.out.println(Arrays.stream(args)
+          .mapToInt(Integer::parseInt)
+          .sum());
+    }
+}

core-java-8/README.md

@@ -33,3 +33,4 @@
 - [An Overview of Regular Expressions Performance in Java](https://www.baeldung.com/java-regex-performance)
 - [Java Primitives versus Objects](https://www.baeldung.com/java-primitives-vs-objects)
 - [How to Use if/else Logic in Java 8 Streams](https://www.baeldung.com/java-8-streams-if-else-logic)
+- [How to Replace Many if Statements in Java](https://www.baeldung.com/java-replace-if-statements)

core-java-8/src/main/java/com/baeldung/interfaces/multiinheritance/Fly.java

@@ -0,0 +1,5 @@
+package com.baeldung.interfaces.multiinheritance;
+
+public abstract interface Fly{
+    void fly();
+}

core-java-8/src/main/java/com/baeldung/interfaces/multiinheritance/Transform.java

@@ -0,0 +1,5 @@
+package com.baeldung.interfaces.multiinheritance;
+
+public interface Transform {
+    void transform();
+}

core-java-8/src/main/java/com/baeldung/interfaces/multiinheritance/Vehicle.java

@@ -0,0 +1,13 @@
+package com.baeldung.interfaces.multiinheritance;
+
+public class Vehicle implements Fly, Transform {
+    @Override
+    public void fly() {
+        System.out.println("I can Fly!!");
+    }
+
+    @Override
+    public void transform() {
+        System.out.println("I can Transform!!");
+    }
+}

core-java-8/src/main/java/com/baeldung/interfaces/polymorphysim/Circle.java

@@ -0,0 +1,21 @@
+package com.baeldung.interfaces.polymorphysim;
+
+public class Circle implements Shape {
+
+    private double radius;
+
+    public Circle(double radius){
+        this.radius = radius;
+    }
+
+    @Override
+    public String name() {
+        return "Circle";
+    }
+
+    @Override
+    public double area() {
+        return Math.PI * (radius * radius);
+    }
+
+}

core-java-8/src/main/java/com/baeldung/interfaces/polymorphysim/DisplayShape.java

@@ -0,0 +1,22 @@
+package com.baeldung.interfaces.polymorphysim;
+
+import java.util.ArrayList;
+
+public class DisplayShape {
+
+    private ArrayList<Shape> shapes;
+
+    public DisplayShape() {
+        shapes = new ArrayList<>();
+    }
+
+    public void add(Shape shape) {
+        shapes.add(shape);
+    }
+
+    public void display() {
+        for (Shape shape : shapes) {
+            System.out.println(shape.name() + " area: " + shape.area());
+        }
+    }
+}

core-java-8/src/main/java/com/baeldung/interfaces/polymorphysim/MainPolymorphic.java

@@ -0,0 +1,15 @@
+package com.baeldung.interfaces.polymorphysim;
+
+public class MainPolymorphic {
+    public static void main(String[] args){
+
+        Shape circleShape = new Circle(2);
+        Shape squareShape = new Square(2);
+
+        DisplayShape displayShape = new DisplayShape();
+        displayShape.add(circleShape);
+        displayShape.add(squareShape);
+
+        displayShape.display();
+    }
+}

core-java-8/src/main/java/com/baeldung/interfaces/polymorphysim/Shape.java

@@ -0,0 +1,6 @@
+package com.baeldung.interfaces.polymorphysim;
+
+public interface Shape {
+    public abstract String name();
+    public abstract double area();
+}

core-java-8/src/main/java/com/baeldung/interfaces/polymorphysim/Square.java

@@ -0,0 +1,20 @@
+package com.baeldung.interfaces.polymorphysim;
+
+public class Square implements Shape {
+
+    private double width;
+
+    public Square(double width) {
+        this.width = width;
+    }
+
+    @Override
+    public String name() {
+        return "Square";
+    }
+
+    @Override
+    public double area() {
+        return width * width;
+    }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/AddCommand.java

@@ -0,0 +1,17 @@
+package com.baeldung.reducingIfElse;
+
+public class AddCommand implements Command {
+
+    private int a;
+    private int b;
+
+    public AddCommand(int a, int b) {
+        this.a = a;
+        this.b = b;
+    }
+
+    @Override
+    public Integer execute() {
+        return a + b;
+    }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/AddRule.java

@@ -0,0 +1,21 @@
+package com.baeldung.reducingIfElse;
+
+public class AddRule implements Rule {
+
+    private int result;
+
+    @Override
+    public boolean evaluate(Expression expression) {
+        boolean evalResult = false;
+        if (expression.getOperator() == Operator.ADD) {
+            this.result = expression.getX() + expression.getY();
+            evalResult = true;
+        }
+        return evalResult;
+    }
+
+    @Override
+    public Result getResult() {
+        return new Result(result);
+    }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Addition.java

@@ -0,0 +1,8 @@
+package com.baeldung.reducingIfElse;
+
+public class Addition implements Operation {
+    @Override
+    public int apply(int a, int b) {
+        return a + b;
+    }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Calculator.java

@@ -0,0 +1,83 @@
+package com.baeldung.reducingIfElse;
+
+public class Calculator {
+
+    public int calculate(int a, int b, String operator) {
+        int result = Integer.MIN_VALUE;
+
+        if ("add".equals(operator)) {
+            result = a + b;
+        } else if ("multiply".equals(operator)) {
+            result = a * b;
+        } else if ("divide".equals(operator)) {
+            result = a / b;
+        } else if ("subtract".equals(operator)) {
+            result = a - b;
+        } else if ("modulo".equals(operator)) {
+            result = a % b;
+        }
+        return result;
+    }
+
+    public int calculateUsingSwitch(int a, int b, String operator) {
+        int result = 0;
+        switch (operator) {
+        case "add":
+            result = a + b;
+            break;
+        case "multiply":
+            result = a * b;
+            break;
+        case "divide":
+            result = a / b;
+            break;
+        case "subtract":
+            result = a - b;
+            break;
+        case "modulo":
+            result = a % b;
+            break;
+        default:
+            result = Integer.MIN_VALUE;
+        }
+        return result;
+    }
+
+    public int calculateUsingSwitch(int a, int b, Operator operator) {
+        int result = 0;
+        switch (operator) {
+        case ADD:
+            result = a + b;
+            break;
+        case MULTIPLY:
+            result = a * b;
+            break;
+        case DIVIDE:
+            result = a / b;
+            break;
+        case SUBTRACT:
+            result = a - b;
+            break;
+        case MODULO:
+            result = a % b;
+            break;
+        default:
+            result = Integer.MIN_VALUE;
+        }
+        return result;
+    }
+
+    public int calculate(int a, int b, Operator operator) {
+        return operator.apply(a, b);
+    }
+
+    public int calculateUsingFactory(int a, int b, String operation) {
+        Operation targetOperation = OperatorFactory.getOperation(operation)
+            .orElseThrow(() -> new IllegalArgumentException("Invalid Operator"));
+        return targetOperation.apply(a, b);
+    }
+
+    public int calculate(Command command) {
+        return command.execute();
+    }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Command.java

@@ -0,0 +1,5 @@
+package com.baeldung.reducingIfElse;
+
+public interface Command {
+    Integer execute();
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Division.java

@@ -0,0 +1,7 @@
+package com.baeldung.reducingIfElse;
+
+public class Division implements Operation {
+        @Override public int apply(int a, int b) {
+                return a / b;
+        }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Expression.java

@@ -0,0 +1,26 @@
+package com.baeldung.reducingIfElse;
+
+public class Expression {
+
+        private Integer x;
+        private Integer y;
+        private Operator operator;
+
+        public Expression(Integer x, Integer y, Operator operator) {
+                this.x = x;
+                this.y = y;
+                this.operator = operator;
+        }
+
+        public Integer getX() {
+                return x;
+        }
+
+        public Integer getY() {
+                return y;
+        }
+
+        public Operator getOperator() {
+                return operator;
+        }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Modulo.java

@@ -0,0 +1,7 @@
+package com.baeldung.reducingIfElse;
+
+public class Modulo implements Operation {
+        @Override public int apply(int a, int b) {
+                return a % b;
+        }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Multiplication.java

@@ -0,0 +1,7 @@
+package com.baeldung.reducingIfElse;
+
+public class Multiplication implements Operation {
+        @Override public int apply(int a, int b) {
+                return 0;
+        }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Operation.java

@@ -0,0 +1,5 @@
+package com.baeldung.reducingIfElse;
+
+public interface Operation {
+    int apply(int a, int b);
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Operator.java

@@ -0,0 +1,41 @@
+package com.baeldung.reducingIfElse;
+
+public enum Operator {
+
+    ADD {
+        @Override
+        public int apply(int a, int b) {
+            return a + b;
+        }
+    },
+
+    MULTIPLY {
+        @Override
+        public int apply(int a, int b) {
+            return a * b;
+        }
+    },
+
+    SUBTRACT {
+        @Override
+        public int apply(int a, int b) {
+            return a - b;
+        }
+    },
+
+    DIVIDE {
+        @Override
+        public int apply(int a, int b) {
+            return a / b;
+        }
+    },
+
+    MODULO {
+        @Override
+        public int apply(int a, int b) {
+            return a % b;
+        }
+    };
+
+    public abstract int apply(int a, int b);
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/OperatorFactory.java

@@ -0,0 +1,21 @@
+package com.baeldung.reducingIfElse;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Optional;
+
+public class OperatorFactory {
+
+    static Map<String, Operation> operationMap = new HashMap<>();
+    static {
+        operationMap.put("add", new Addition());
+        operationMap.put("divide", new Division());
+        operationMap.put("multiply", new Multiplication());
+        operationMap.put("subtract", new Subtraction());
+        operationMap.put("modulo", new Modulo());
+    }
+
+    public static Optional<Operation> getOperation(String operation) {
+        return Optional.ofNullable(operationMap.get(operation));
+    }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Result.java

@@ -0,0 +1,13 @@
+package com.baeldung.reducingIfElse;
+
+public class Result {
+    int value;
+
+    public Result(int value) {
+        this.value = value;
+    }
+
+    public int getValue() {
+        return value;
+    }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Rule.java

@@ -0,0 +1,8 @@
+package com.baeldung.reducingIfElse;
+
+public interface Rule {
+
+    boolean evaluate(Expression expression);
+
+    Result getResult();
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/RuleEngine.java

@@ -0,0 +1,24 @@
+package com.baeldung.reducingIfElse;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+public class RuleEngine {
+
+    private static List<Rule> rules = new ArrayList<>();
+
+    static {
+        rules.add(new AddRule());
+    }
+
+    public Result process(Expression expression) {
+
+        Rule rule = rules.stream()
+            .filter(r -> r.evaluate(expression))
+            .findFirst()
+            .orElseThrow(() -> new IllegalArgumentException("Expression does not matches any Rule"));
+        return rule.getResult();
+    }
+}

core-java-8/src/main/java/com/baeldung/reducingIfElse/Subtraction.java

@@ -0,0 +1,7 @@
+package com.baeldung.reducingIfElse;
+
+public class Subtraction implements Operation {
+        @Override public int apply(int a, int b) {
+                return a - b;
+        }
+}

core-java-8/src/test/java/com/baeldung/interfaces/PolymorphysimUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.interfaces;
+
+import com.baeldung.interfaces.polymorphysim.Circle;
+import com.baeldung.interfaces.polymorphysim.Shape;
+import com.baeldung.interfaces.polymorphysim.Square;
+import org.assertj.core.api.Assertions;
+import org.junit.Test;
+
+public class PolymorphysimUnitTest {
+
+    @Test
+    public void whenInterfacePointsToCircle_CircleAreaMethodisBeingCalled(){
+        double expectedArea = 12.566370614359172;
+        Shape circle = new Circle(2);
+        double actualArea = circle.area();
+        Assertions.assertThat(actualArea).isEqualTo(expectedArea);
+    }
+
+    @Test
+    public void whenInterfacePointsToSquare_SquareAreaMethodisBeingCalled(){
+        double expectedArea = 4;
+        Shape square = new Square(2);
+        double actualArea = square.area();
+        Assertions.assertThat(actualArea).isEqualTo(expectedArea);
+    }
+}

core-java-8/src/test/java/com/baeldung/reduceIfelse/CalculatorUnitTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.reduceIfelse;
+
+import com.baeldung.reducingIfElse.AddCommand;
+import com.baeldung.reducingIfElse.Calculator;
+import com.baeldung.reducingIfElse.Operator;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class CalculatorUnitTest {
+
+    @Test
+    public void whenCalculateUsingStringOperator_thenReturnCorrectResult() {
+        Calculator calculator = new Calculator();
+        int result = calculator.calculate(3, 4, "add");
+        assertEquals(7, result);
+    }
+
+    @Test
+    public void whenCalculateUsingEnumOperator_thenReturnCorrectResult() {
+        Calculator calculator = new Calculator();
+        int result = calculator.calculate(3, 4, Operator.valueOf("ADD"));
+        assertEquals(7, result);
+    }
+
+    @Test
+    public void whenCalculateUsingCommand_thenReturnCorrectResult() {
+        Calculator calculator = new Calculator();
+        int result = calculator.calculate(new AddCommand(3, 7));
+        assertEquals(10, result);
+    }
+}

core-java-8/src/test/java/com/baeldung/reduceIfelse/RuleEngineUnitTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.reduceIfelse;
+
+import com.baeldung.reducingIfElse.Expression;
+import com.baeldung.reducingIfElse.Operator;
+import com.baeldung.reducingIfElse.Result;
+import com.baeldung.reducingIfElse.RuleEngine;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+public class RuleEngineUnitTest {
+
+    @Test
+    public void whenNumbersGivenToRuleEngine_thenReturnCorrectResult() {
+        Expression expression = new Expression(5, 5, Operator.ADD);
+        RuleEngine engine = new RuleEngine();
+        Result result = engine.process(expression);
+
+        assertNotNull(result);
+        assertEquals(10, result.getValue());
+    }
+}

core-java-9/pom.xml

@@ -1,7 +1,6 @@
 <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>
-    <groupId>com.baeldung</groupId>
     <artifactId>core-java-9</artifactId>
     <version>0.2-SNAPSHOT</version>
     <name>core-java-9</name>

core-java-arrays/.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-arrays/README.md

@@ -0,0 +1,15 @@
+=========
+
+## Core Java Arrays Cookbooks and Examples
+
+### Relevant Articles: 
+- [How to Copy an Array in Java](http://www.baeldung.com/java-array-copy)
+- [Check if a Java Array Contains a Value](http://www.baeldung.com/java-array-contains-value)
+- [Initializing Arrays in Java](http://www.baeldung.com/java-initialize-array)
+- [Guide to the java.util.Arrays Class](http://www.baeldung.com/java-util-arrays)
+- [Jagged Arrays In Java](http://www.baeldung.com/java-jagged-arrays)
+- [Find Sum and Average in a Java Array](http://www.baeldung.com/java-array-sum-average)
+- [Arrays in Java: A Reference Guide](https://www.baeldung.com/java-arrays-guide)
+- [How to Invert an Array in Java](http://www.baeldung.com/java-invert-array)
+- [Array Operations in Java](http://www.baeldung.com/java-common-array-operations)
+- [Intersection Between two Integer Arrays](https://www.baeldung.com/java-array-intersection)

core-java-arrays/pom.xml

@@ -0,0 +1,412 @@
+<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>
+    <groupId>com.baeldung</groupId>
+    <artifactId>core-java-arrays</artifactId>
+    <version>0.1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>core-java-arrays</name>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-java</relativePath>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-lang3</artifactId>
+            <version>${commons-lang3.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>log4j</groupId>
+            <artifactId>log4j</artifactId>
+            <version>${log4j.version}</version>
+        </dependency>
+        <dependency> <!-- needed to bridge to slf4j for projects that use the log4j APIs directly -->
+            <groupId>org.slf4j</groupId>
+            <artifactId>log4j-over-slf4j</artifactId>
+            <version>${org.slf4j.version}</version>
+        </dependency>
+        <!-- test scoped -->
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <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-annprocess.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-web</artifactId>
+            <version>${springframework.spring-web.version}</version>
+        </dependency>
+    </dependencies>
+
+    <build>
+        <finalName>core-java-arrays</finalName>
+        <resources>
+            <resource>
+                <directory>src/main/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
+
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <configuration>
+                    <excludes>
+                        <exclude>**/*LiveTest.java</exclude>
+                        <exclude>**/*IntegrationTest.java</exclude>
+                        <exclude>**/*IntTest.java</exclude>
+                        <exclude>**/*LongRunningUnitTest.java</exclude>
+                        <exclude>**/*ManualTest.java</exclude>
+                    </excludes>
+                    <testFailureIgnore>true</testFailureIgnore>
+                </configuration>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-dependency-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <id>copy-dependencies</id>
+                        <phase>prepare-package</phase>
+                        <goals>
+                            <goal>copy-dependencies</goal>
+                        </goals>
+                        <configuration>
+                            <outputDirectory>${project.build.directory}/libs</outputDirectory>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-jar-plugin</artifactId>
+                <version>${maven-jar-plugin.version}</version>
+                <configuration>
+                    <archive>
+                        <manifest>
+                            <addClasspath>true</addClasspath>
+                            <classpathPrefix>libs/</classpathPrefix>
+                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
+                        </manifest>
+                    </archive>
+                </configuration>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-assembly-plugin</artifactId>
+                <executions>
+                    <execution>
+                        <phase>package</phase>
+                        <goals>
+                            <goal>single</goal>
+                        </goals>
+                        <configuration>
+                            <archiveBaseDirectory>${project.basedir}</archiveBaseDirectory>
+                            <archive>
+                                <manifest>
+                                    <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
+                                </manifest>
+                            </archive>
+                            <descriptorRefs>
+                                <descriptorRef>jar-with-dependencies</descriptorRef>
+                            </descriptorRefs>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-shade-plugin</artifactId>
+                <version>${maven-shade-plugin.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>shade</goal>
+                        </goals>
+                        <configuration>
+                            <shadedArtifactAttached>true</shadedArtifactAttached>
+                            <transformers>
+                                <transformer implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
+                                    <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
+                                </transformer>
+                            </transformers>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <groupId>com.jolira</groupId>
+                <artifactId>onejar-maven-plugin</artifactId>
+                <version>${onejar-maven-plugin.version}</version>
+                <executions>
+                    <execution>
+                        <configuration>
+                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
+                            <attachToBuild>true</attachToBuild>
+                            <filename>${project.build.finalName}-onejar.${project.packaging}</filename>
+                        </configuration>
+                        <goals>
+                            <goal>one-jar</goal>
+                        </goals>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+                <version>${spring-boot-maven-plugin.version}</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>repackage</goal>
+                        </goals>
+                        <configuration>
+                            <classifier>spring-boot</classifier>
+                            <mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
+                        </configuration>
+                    </execution>
+                </executions>
+            </plugin>
+
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>exec-maven-plugin</artifactId>
+                <version>${exec-maven-plugin.version}</version>
+                <configuration>
+                    <executable>java</executable>
+                    <mainClass>com.baeldung.outofmemoryerror.OutOfMemoryGCLimitExceed</mainClass>
+                    <arguments>
+                        <argument>-Xmx300m</argument>
+                        <argument>-XX:+UseParallelGC</argument>
+                        <argument>-classpath</argument>
+                        <classpath />
+                        <argument>com.baeldung.outofmemoryerror.OutOfMemoryGCLimitExceed</argument>
+                    </arguments>
+                </configuration>
+            </plugin>
+            
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-javadoc-plugin</artifactId>
+                <version>${maven-javadoc-plugin.version}</version>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+    <profiles>
+        <profile>
+            <id>integration</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <phase>integration-test</phase>
+                                <goals>
+                                    <goal>test</goal>
+                                </goals>
+                                <configuration>
+                                    <excludes>
+                                        <exclude>**/*ManualTest.java</exclude>
+                                    </excludes>
+                                    <includes>
+                                        <include>**/*IntegrationTest.java</include>
+                                        <include>**/*IntTest.java</include>
+                                    </includes>
+                                </configuration>
+                            </execution>
+                        </executions>
+                        <configuration>
+                            <systemPropertyVariables>
+                                <test.mime>json</test.mime>
+                            </systemPropertyVariables>
+                        </configuration>
+                    </plugin>
+                    <plugin>
+                        <groupId>org.codehaus.mojo</groupId>
+                        <artifactId>exec-maven-plugin</artifactId>
+                        <version>${exec-maven-plugin.version}</version>
+                        <executions>
+                            <execution>
+                                <id>run-benchmarks</id>
+                                <!-- <phase>integration-test</phase> -->
+                                <phase>none</phase>
+                                <goals>
+                                    <goal>exec</goal>
+                                </goals>
+                                <configuration>
+                                    <classpathScope>test</classpathScope>
+                                    <executable>java</executable>
+                                    <arguments>
+                                        <argument>-classpath</argument>
+                                        <classpath />
+                                        <argument>org.openjdk.jmh.Main</argument>
+                                        <argument>.*</argument>
+                                    </arguments>
+                                </configuration>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+
+        <!-- java instrumentation profiles to build jars -->
+        <profile>
+            <id>buildAgentLoader</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-jar-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <phase>package</phase>
+                                <goals>
+                                    <goal>jar</goal>
+                                </goals>
+                                <configuration>
+                                    <classifier>agentLoader</classifier>
+                                    <classesDirectory>target/classes</classesDirectory>
+                                    <archive>
+                                        <manifest>
+                                            <addClasspath>true</addClasspath>
+                                        </manifest>
+                                        <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
+                                    </archive>
+
+                                    <includes>
+                                        <include>com/baeldung/instrumentation/application/AgentLoader.class</include>
+                                        <include>com/baeldung/instrumentation/application/Launcher.class</include>
+                                    </includes>
+                                </configuration>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+        <profile>
+            <id>buildApplication</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-jar-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <phase>package</phase>
+                                <goals>
+                                    <goal>jar</goal>
+                                </goals>
+                                <configuration>
+                                    <classifier>application</classifier>
+                                    <classesDirectory>target/classes</classesDirectory>
+                                    <archive>
+                                        <manifest>
+                                            <addClasspath>true</addClasspath>
+                                        </manifest>
+                                        <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
+                                    </archive>
+
+                                    <includes>
+                                        <include>com/baeldung/instrumentation/application/MyAtm.class</include>
+                                        <include>com/baeldung/instrumentation/application/MyAtmApplication.class</include>
+                                        <include>com/baeldung/instrumentation/application/Launcher.class</include>
+                                    </includes>
+                                </configuration>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+        <profile>
+            <id>buildAgent</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-jar-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <phase>package</phase>
+                                <goals>
+                                    <goal>jar</goal>
+                                </goals>
+                                <configuration>
+                                    <classifier>agent</classifier>
+                                    <classesDirectory>target/classes</classesDirectory>
+                                    <archive>
+                                        <manifest>
+                                            <addClasspath>true</addClasspath>
+                                        </manifest>
+                                        <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
+                                    </archive>
+
+                                    <includes>
+                                        <include>com/baeldung/instrumentation/agent/AtmTransformer.class</include>
+                                        <include>com/baeldung/instrumentation/agent/MyInstrumentationAgent.class</include>
+                                    </includes>
+                                </configuration>
+                            </execution>
+                        </executions>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
+    <properties>
+
+        <!-- util -->
+        <commons-lang3.version>3.8.1</commons-lang3.version>
+        <lombok.version>1.16.12</lombok.version>
+        
+        <jmh-core.version>1.19</jmh-core.version>
+        <jmh-generator-annprocess.version>1.19</jmh-generator-annprocess.version>
+
+        <!-- testing -->
+        <assertj-core.version>3.10.0</assertj-core.version>
+
+        <!-- maven and spring plugins -->
+        <maven-surefire-plugin.version>2.21.0</maven-surefire-plugin.version>
+        <springframework.spring-web.version>4.3.4.RELEASE</springframework.spring-web.version>
+        <maven-javadoc-plugin.version>3.0.0-M1</maven-javadoc-plugin.version>
+        <maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
+        <onejar-maven-plugin.version>1.4.4</onejar-maven-plugin.version>
+        <maven-shade-plugin.version>3.1.1</maven-shade-plugin.version>
+        <spring-boot-maven-plugin.version>2.0.3.RELEASE</spring-boot-maven-plugin.version>
+        <exec-maven-plugin.version>1.6.0</exec-maven-plugin.version>
+    </properties>
+
+</project>

core-java-arrays/src/main/java/com/baeldung/array/ArrayInitializer.java

@@ -2,7 +2,7 @@ package com.baeldung.array;
 
 import java.util.Arrays;
 
-import org.apache.commons.lang.ArrayUtils;
+import org.apache.commons.lang3.ArrayUtils;
 
 public class ArrayInitializer {
 

core-java-arrays/src/main/java/com/baeldung/array/operations/ArrayOperations.java

@@ -4,11 +4,13 @@ import java.lang.reflect.Array;
 import java.util.Arrays;
 import java.util.HashSet;
 import java.util.LinkedHashSet;
+import java.util.LinkedList;
 import java.util.Random;
 import java.util.Set;
 import java.util.function.Function;
 import java.util.function.IntPredicate;
 import java.util.function.Predicate;
+import java.util.stream.Stream;
 
 import org.apache.commons.lang3.ArrayUtils;
 
@@ -194,4 +196,16 @@ public class ArrayOperations {
     public static <T> T getRandomFromObjectArray(T[] array) {
         return array[new Random().nextInt(array.length)];
     }
+
+    public static Integer[] intersectionSimple(final Integer[] a, final Integer[] b){
+        return Stream.of(a).filter(Arrays.asList(b)::contains).toArray(Integer[]::new);
+    }
+
+    public static Integer[] intersectionSet(final Integer[] a, final Integer[] b){
+        return Stream.of(a).filter(Arrays.asList(b)::contains).distinct().toArray(Integer[]::new);
+    }
+
+    public static Integer[] intersectionMultiSet(final Integer[] a, final Integer[] b){
+        return Stream.of(a).filter(new LinkedList<>(Arrays.asList(b))::remove).toArray(Integer[]::new);
+    }
 }