Merge remote-tracking branch 'eugenp/master'

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-miscellaneous-1/pom.xml

@@ -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/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-2/pom.xml

@@ -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/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++];

core-java-arrays/README.md

@@ -12,4 +12,4 @@
 - [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-collections/README.md

@@ -51,3 +51,4 @@
 - [Java List Initialization in One Line](https://www.baeldung.com/java-init-list-one-line)
 - [ClassCastException: Arrays$ArrayList cannot be cast to ArrayList](https://www.baeldung.com/java-classcastexception-arrays-arraylist)
 - [A Guide to EnumMap](https://www.baeldung.com/java-enum-map)
+- [Ways to Iterate Over a List in Java](https://www.baeldung.com/java-iterate-list)

core-java-concurrency/README.md

@@ -31,3 +31,4 @@
 - [Runnable vs. Callable in Java](http://www.baeldung.com/java-runnable-callable)
 - [Brief Introduction to Java Thread.yield()](https://www.baeldung.com/java-thread-yield)
 - [Print Even and Odd Numbers Using 2 Threads](https://www.baeldung.com/java-even-odd-numbers-with-2-threads)
+- [Java CyclicBarrier vs CountDownLatch](https://www.baeldung.com/java-cyclicbarrier-countdownlatch)

core-java-concurrency/src/main/java/com/baeldung/concurrent/Scheduledexecutorservice/ScheduledExecutorServiceDemo.java

@@ -1,34 +1,52 @@
 package com.baeldung.concurrent.Scheduledexecutorservice;
 
 import java.util.concurrent.Executors;
-import java.util.concurrent.Future;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Function;
 
 public class ScheduledExecutorServiceDemo {
 
-	public void execute() {
+	private void execute() {
 		ScheduledExecutorService executorService = Executors.newSingleThreadScheduledExecutor();
-
-		ScheduledFuture<?> scheduledFuture = executorService.schedule(() -> {
-			// Task
-		}, 1, TimeUnit.SECONDS);
-
-		executorService.scheduleAtFixedRate(() -> {
-			// Task
-		}, 1, 10, TimeUnit.SECONDS);
-
-		executorService.scheduleWithFixedDelay(() -> {
-			// Task
-		}, 1, 10, TimeUnit.SECONDS);
-
-		Future<String> future = executorService.schedule(() -> {
-			// Task
-			return "Hellow world";
-		}, 1, TimeUnit.SECONDS);
-
+		getTasksToRun().apply(executorService);
 		executorService.shutdown();
 	}
 
+	private void executeWithMultiThread() {
+		ScheduledExecutorService executorService = Executors.newScheduledThreadPool(2);
+		getTasksToRun().apply(executorService);
+		executorService.shutdown();
+	}
+
+	private Function<ScheduledExecutorService, Void> getTasksToRun() {
+		return (executorService -> {
+			ScheduledFuture<?> scheduledFuture1 = executorService.schedule(() -> {
+				// Task
+			}, 1, TimeUnit.SECONDS);
+
+			ScheduledFuture<?> scheduledFuture2 = executorService.scheduleAtFixedRate(() -> {
+				// Task
+			}, 1, 10, TimeUnit.SECONDS);
+
+			ScheduledFuture<?> scheduledFuture3 = executorService.scheduleWithFixedDelay(() -> {
+				// Task
+			}, 1, 10, TimeUnit.SECONDS);
+
+			ScheduledFuture<String> scheduledFuture4 = executorService.schedule(() -> {
+				// Task
+				return "Hellow world";
+			}, 1, TimeUnit.SECONDS);
+			return null;
+		});
+	}
+
+	public static void main(String... args) {
+		ScheduledExecutorServiceDemo demo = new ScheduledExecutorServiceDemo();
+		demo.execute();
+		demo.executeWithMultiThread();
+	}
+
+
 }

core-java-concurrency/src/main/java/com/baeldung/concurrent/daemon/MultipleThreadsExample.java

@@ -0,0 +1,12 @@
+package com.baeldung.concurrent.daemon;
+
+public class MultipleThreadsExample {
+    public static void main(String[] args) {
+        NewThread t1 = new NewThread();
+        t1.setName("MyThread-1");
+        NewThread t2 = new NewThread();
+        t2.setName("MyThread-2");
+        t1.start();
+        t2.start();
+    }
+}

core-java-concurrency/src/main/java/com/baeldung/concurrent/daemon/NewThread.java

@@ -1,14 +1,18 @@
 package com.baeldung.concurrent.daemon;
 
 public class NewThread extends Thread {
-
     public void run() {
     	long startTime = System.currentTimeMillis();
         while (true) {
             for (int i = 0; i < 10; i++) {
-                System.out.println("New Thread is running..." + i);
+                System.out.println(this.getName() + ": New Thread is running..." + i);
+                try {
+                    //Wait for one sec so it doesn't print too fast
+                    Thread.sleep(1000);
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
             }
-            
             // prevent the Thread to run forever. It will finish it's execution after 2 seconds
             if (System.currentTimeMillis() - startTime > 2000) {
             	Thread.currentThread().interrupt();

core-java-concurrency/src/main/java/com/baeldung/concurrent/daemon/SingleThreadExample.java

@@ -0,0 +1,8 @@
+package com.baeldung.concurrent.daemon;
+
+public class SingleThreadExample {
+    public static void main(String[] args) {
+        NewThread t = new NewThread();
+        t.start();
+    }
+}

core-java-lang/README.md

@@ -58,4 +58,4 @@
 - [Inheritance and Composition (Is-a vs Has-a relationship) in Java](http://www.baeldung.com/java-inheritance-composition)
 - [A Guide to Constructors in Java](https://www.baeldung.com/java-constructors)
 - [Retrieving a Class Name in Java](https://www.baeldung.com/java-class-name)
-
+- [Java equals() and hashCode() Contracts](https://www.baeldung.com/java-equals-hashcode-contracts)

core-java-net/README.md

@@ -1,3 +0,0 @@
-=========
-
-## Core Java Net

core-java-networking/README.md

@@ -0,0 +1,7 @@
+=========
+
+## Core Java Networking
+
+### Relevant Articles
+
+- [Connecting Through Proxy Servers in Core Java](https://www.baeldung.com/java-connect-via-proxy-server)

core-java-networking/pom.xml

@@ -1,10 +1,10 @@
 <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-net</artifactId>
+    <artifactId>core-java-networking</artifactId>
     <version>0.1.0-SNAPSHOT</version>
     <packaging>jar</packaging>
-    <name>core-java-net</name>
+    <name>core-java-networking</name>
 
     <parent>
         <groupId>com.baeldung</groupId>
@@ -14,6 +14,6 @@
     </parent>
 
     <build>
-        <finalName>core-java-net</finalName>
+        <finalName>core-java-networking</finalName>
     </build>
 </project>

core-java/README.md

@@ -89,3 +89,6 @@
 - [Java – Try with Resources](https://www.baeldung.com/java-try-with-resources)
 - [Abstract Classes in Java](https://www.baeldung.com/java-abstract-class)
 - [Guide to Character Encoding](https://www.baeldung.com/java-char-encoding)
+- [Calculate the Area of a Circle in Java](https://www.baeldung.com/java-calculate-circle-area)
+- [A Guide to the Java Math Class](https://www.baeldung.com/java-lang-math)
+- [Graphs in Java](https://www.baeldung.com/java-graphs)

core-java/src/main/java/com/baeldung/basicsyntax/SimpleAddition.java

@@ -0,0 +1,11 @@
+package com.baeldung.basicsyntax;
+
+public class SimpleAddition {
+
+    public static void main(String[] args) {
+        int a = 10;
+        int b = 5;
+        double c = a + b;
+        System.out.println( a + " + " + b + " = " + c);
+    }
+}

core-java/src/test/java/com/baeldung/java/properties/PropertiesUnitTest.java

@@ -0,0 +1,171 @@
+package com.baeldung.java.properties;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.Enumeration;
+import java.util.Properties;
+
+import org.junit.Test;
+
+public class PropertiesUnitTest {
+
+    @Test
+    public void givenPropertyValue_whenPropertiesFileLoaded_thenCorrect() throws IOException {
+     
+        String rootPath = Thread.currentThread().getContextClassLoader().getResource("").getPath();
+        String appConfigPath = rootPath + "app.properties";
+        String catalogConfigPath = rootPath + "catalog";
+        
+        Properties appProps = new Properties();
+        appProps.load(new FileInputStream(appConfigPath));
+         
+        Properties catalogProps = new Properties();
+        catalogProps.load(new FileInputStream(catalogConfigPath));
+        
+        String appVersion = appProps.getProperty("version");
+        assertEquals("1.0", appVersion);
+        
+        assertEquals("files", catalogProps.getProperty("c1"));
+    }
+    
+    @Test
+    public void givenPropertyValue_whenXMLPropertiesFileLoaded_thenCorrect() throws IOException {
+     
+        String rootPath = Thread.currentThread().getContextClassLoader().getResource("").getPath();
+        String iconConfigPath = rootPath + "icons.xml";
+        Properties iconProps = new Properties();
+        iconProps.loadFromXML(new FileInputStream(iconConfigPath));
+        
+        assertEquals("icon1.jpg", iconProps.getProperty("fileIcon"));
+    }
+    
+    @Test
+    public void givenAbsentProperty_whenPropertiesFileLoaded_thenReturnsDefault() throws IOException {
+    
+        String rootPath = Thread.currentThread().getContextClassLoader().getResource("").getPath();
+        String appConfigPath = rootPath + "app.properties";
+        Properties appProps = new Properties();
+        appProps.load(new FileInputStream(appConfigPath));
+        
+        String appVersion = appProps.getProperty("version");
+        String appName = appProps.getProperty("name", "defaultName");
+        String appGroup = appProps.getProperty("group", "baeldung");
+        String appDownloadAddr = appProps.getProperty("downloadAddr");
+        
+        assertEquals("1.0", appVersion);
+        assertEquals("TestApp", appName);
+        assertEquals("baeldung", appGroup);
+        assertNull(appDownloadAddr);
+    }
+    
+    @Test(expected = Exception.class)
+    public void givenImproperObjectCasting_whenPropertiesFileLoaded_thenThrowsException() throws IOException {
+        
+        String rootPath = Thread.currentThread().getContextClassLoader().getResource("").getPath();
+        String appConfigPath = rootPath + "app.properties";
+        Properties appProps = new Properties();
+        appProps.load(new FileInputStream(appConfigPath));
+        
+        float appVerFloat = (float) appProps.get("version");
+    }
+    
+    @Test
+    public void givenPropertyValue_whenPropertiesSet_thenCorrect() throws IOException {
+        
+        String rootPath = Thread.currentThread().getContextClassLoader().getResource("").getPath();
+        String appConfigPath = rootPath + "app.properties";
+        Properties appProps = new Properties();
+        appProps.load(new FileInputStream(appConfigPath));
+        
+        appProps.setProperty("name", "NewAppName");
+        appProps.setProperty("downloadAddr", "www.baeldung.com/downloads");
+        
+        String newAppName = appProps.getProperty("name");
+        assertEquals("NewAppName", newAppName);
+        
+        String newAppDownloadAddr = appProps.getProperty("downloadAddr");
+        assertEquals("www.baeldung.com/downloads", newAppDownloadAddr);
+    }
+    
+    @Test
+    public void givenPropertyValueNull_whenPropertiesRemoved_thenCorrect() throws IOException {
+        
+        String rootPath = Thread.currentThread().getContextClassLoader().getResource("").getPath();
+        String appConfigPath = rootPath + "app.properties";
+        Properties appProps = new Properties();
+        appProps.load(new FileInputStream(appConfigPath));
+        
+        String versionBeforeRemoval = appProps.getProperty("version");
+        assertEquals("1.0", versionBeforeRemoval);
+
+        appProps.remove("version");    
+        String versionAfterRemoval = appProps.getProperty("version");
+        assertNull(versionAfterRemoval);
+    }
+    
+    @Test
+    public void whenPropertiesStoredInFile_thenCorrect() throws IOException {
+        
+        String rootPath = Thread.currentThread().getContextClassLoader().getResource("").getPath();
+        String appConfigPath = rootPath + "app.properties";
+        Properties appProps = new Properties();
+        appProps.load(new FileInputStream(appConfigPath));
+        
+        String newAppConfigPropertiesFile = rootPath + "newApp.properties";
+        appProps.store(new FileWriter(newAppConfigPropertiesFile), "store to properties file");
+        
+        String newAppConfigXmlFile = rootPath + "newApp.xml";
+        appProps.storeToXML(new FileOutputStream(newAppConfigXmlFile), "store to xml file");
+    }
+    
+    @Test
+    public void givenPropertyValueAbsent_LoadsValuesFromDefaultProperties() throws IOException {
+        
+        String rootPath = Thread.currentThread().getContextClassLoader().getResource("").getPath();
+        
+        String defaultConfigPath = rootPath + "default.properties";
+        Properties defaultProps = new Properties();
+        defaultProps.load(new FileInputStream(defaultConfigPath));
+         
+        String appConfigPath = rootPath + "app.properties";
+        Properties appProps = new Properties(defaultProps);
+        appProps.load(new FileInputStream(appConfigPath));
+         
+        String appName = appProps.getProperty("name");        
+        String appVersion = appProps.getProperty("version");
+        String defaultSite = appProps.getProperty("site");
+        
+        assertEquals("1.0", appVersion);
+        assertEquals("TestApp", appName);
+        assertEquals("www.google.com", defaultSite);
+    }
+
+    @Test
+    public void givenPropertiesSize_whenPropertyFileLoaded_thenCorrect() throws IOException {
+        
+        String rootPath = Thread.currentThread().getContextClassLoader().getResource("").getPath();
+        String appPropsPath = rootPath + "app.properties";
+        Properties appProps = new Properties();
+        appProps.load(new FileInputStream(appPropsPath));
+         
+        appProps.list(System.out); // list all key-value pairs
+        
+        Enumeration<Object> valueEnumeration = appProps.elements();
+        while (valueEnumeration.hasMoreElements()) {
+            System.out.println(valueEnumeration.nextElement());
+        }
+         
+        Enumeration<Object> keyEnumeration = appProps.keys();
+        while (keyEnumeration.hasMoreElements()) {
+            System.out.println(keyEnumeration.nextElement());
+        }
+         
+        int size = appProps.size();
+        assertEquals(3, size);
+    }
+}

core-java/src/test/resources/app.properties

@@ -0,0 +1,3 @@
+version=1.0
+name=TestApp
+date=2016-11-12

core-java/src/test/resources/catalog

@@ -0,0 +1,3 @@
+c1=files
+c2=images
+c3=videos

core-java/src/test/resources/default.properties

@@ -0,0 +1,4 @@
+site=www.google.com
+name=DefaultAppName
+topic=Properties
+category=core-java

core-java/src/test/resources/icons.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE properties SYSTEM "http://java.sun.com/dtd/properties.dtd">
+<properties>
+    <comment>xml example</comment>
+    <entry key="fileIcon">icon1.jpg</entry>
+    <entry key="imageIcon">icon2.jpg</entry>
+    <entry key="videoIcon">icon3.jpg</entry>
+</properties>

core-kotlin/README.md

@@ -47,3 +47,4 @@
 - [Guide to Sorting in Kotlin](https://www.baeldung.com/kotlin-sort)
 - [Dependency Injection for Kotlin with Injekt](https://www.baeldung.com/kotlin-dependency-injection-with-injekt)
 - [Implementing a Binary Tree in Kotlin](https://www.baeldung.com/kotlin-binary-tree)
+- [Generate a Random Alphanumeric String in Kotlin](https://www.baeldung.com/kotlin-random-alphanumeric-string)

core-kotlin/src/main/kotlin/com/baeldung/functions/Inline.kt

@@ -0,0 +1,28 @@
+package com.baeldung.functions
+
+import kotlin.random.Random
+
+/**
+ * An extension function on all collections to apply a function to all collection
+ * elements.
+ */
+fun <T> Collection<T>.each(block: (T) -> Unit) {
+    for (e in this) block(e)
+}
+
+/**
+ * In order to see the the JVM bytecode:
+ *  1. Compile the Kotlin file using `kotlinc Inline.kt`
+ *  2. Take a peek at the bytecode using the `javap -c InlineKt`
+ */
+fun main() {
+    val numbers = listOf(1, 2, 3, 4, 5)
+    val random = random()
+
+    numbers.each { println(random * it) } // capturing the random variable
+}
+
+/**
+ * Generates a random number.
+ */
+private fun random(): Int = Random.nextInt()

events/README.md

@@ -1 +0,0 @@
-## Relevant articles:

java-dates/README.md

@@ -24,4 +24,5 @@
 - [Add Hours To a Date In Java](http://www.baeldung.com/java-add-hours-date)
 - [Guide to DateTimeFormatter](https://www.baeldung.com/java-datetimeformatter)
 - [Format ZonedDateTime to String](https://www.baeldung.com/java-format-zoned-datetime-string)
-- [Convert Between java.time.Instant and java.sql.Timestamp](Convert Between java.time.Instant and java.sql.Timestamp)
+- [Convert Between java.time.Instant and java.sql.Timestamp](https://www.baeldung.com/java-time-instant-to-java-sql-timestamp)
+- [Convert between String and Timestamp](https://www.baeldung.com/java-string-to-timestamp)

java-dates/src/test/java/com/baeldung/date/DateDiffUnitTest.java

@@ -8,6 +8,7 @@ import java.time.Duration;
 import java.time.LocalDate;
 import java.time.LocalDateTime;
 import java.time.Period;
+import java.time.temporal.ChronoUnit;
 import java.util.Date;
 import java.util.Locale;
 import java.util.TimeZone;
@@ -51,6 +52,16 @@ public class DateDiffUnitTest {
         assertEquals(diff, 6);
     }
 
+    @Test
+    public void givenTwoDateTimesInJava8_whenDifferentiatingInSeconds_thenWeGetTen() {
+        LocalDateTime now = LocalDateTime.now();
+        LocalDateTime tenSecondsLater = now.plusSeconds(10);
+
+        long diff = ChronoUnit.SECONDS.between(now, tenSecondsLater);
+
+        assertEquals(diff, 10);
+    }
+
     @Test
     public void givenTwoZonedDateTimesInJava8_whenDifferentiating_thenWeGetSix() {
         LocalDateTime ldt = LocalDateTime.now();
@@ -60,6 +71,16 @@ public class DateDiffUnitTest {
         assertEquals(diff, 6);
     }
 
+    @Test
+    public void givenTwoDateTimesInJava8_whenDifferentiatingInSecondsUsingUntil_thenWeGetTen() {
+        LocalDateTime now = LocalDateTime.now();
+        LocalDateTime tenSecondsLater = now.plusSeconds(10);
+
+        long diff = now.until(tenSecondsLater, ChronoUnit.SECONDS);
+
+        assertEquals(diff, 10);
+    }
+
     @Test
     public void givenTwoDatesInJodaTime_whenDifferentiating_thenWeGetSix() {
         org.joda.time.LocalDate now = org.joda.time.LocalDate.now();

java-streams/pom.xml

@@ -1,5 +1,5 @@
 <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">
+         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>java-streams</artifactId>
     <version>0.1.0-SNAPSHOT</version>
@@ -74,6 +74,11 @@
             <artifactId>aspectjweaver</artifactId>
             <version>${asspectj.version}</version>
         </dependency>
+        <dependency>
+            <groupId>pl.touk</groupId>
+            <artifactId>throwing-function</artifactId>
+            <version>${throwing-function.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -108,8 +113,9 @@
         <protonpack.version>1.15</protonpack.version>
         <streamex.version>0.6.5</streamex.version>
         <joda.version>2.10</joda.version>
+        <throwing-function.version>1.3</throwing-function.version>
         <!-- testing -->
-        <assertj.version>3.6.1</assertj.version>
+        <assertj.version>3.11.1</assertj.version>
         <asspectj.version>1.8.9</asspectj.version>
     </properties>
 </project>

java-streams/src/main/java/com/baeldung/stream/filter/Customer.java

@@ -0,0 +1,55 @@
+package com.baeldung.stream.filter;
+
+import javax.net.ssl.HttpsURLConnection;
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.URL;
+
+public class Customer {
+    private String name;
+    private int points;
+    private String profilePhotoUrl;
+
+    public Customer(String name, int points) {
+        this(name, points, "");
+    }
+
+    public Customer(String name, int points, String profilePhotoUrl) {
+        this.name = name;
+        this.points = points;
+        this.profilePhotoUrl = profilePhotoUrl;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getPoints() {
+        return points;
+    }
+
+    public boolean hasOver(int points) {
+        return this.points > points;
+    }
+
+    public boolean hasOverThousandPoints() {
+        return this.points > 100;
+    }
+
+    public boolean hasValidProfilePhoto() throws IOException {
+        URL url = new URL(this.profilePhotoUrl);
+        HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
+        return connection.getResponseCode() == HttpURLConnection.HTTP_OK;
+    }
+
+    public boolean hasValidProfilePhotoWithoutCheckedException() {
+        try {
+            URL url = new URL(this.profilePhotoUrl);
+            HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
+            return connection.getResponseCode() == HttpURLConnection.HTTP_OK;
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+}

java-streams/src/test/java/com/baeldung/stream/filter/StreamFilterUnitTest.java

@@ -0,0 +1,159 @@
+package com.baeldung.stream.filter;
+
+import org.junit.jupiter.api.Test;
+import pl.touk.throwing.ThrowingPredicate;
+import pl.touk.throwing.exception.WrappedException;
+
+import java.io.IOException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Optional;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThatThrownBy;
+
+public class StreamFilterUnitTest {
+
+    @Test
+    public void givenListOfCustomers_whenFilterByPoints_thenGetTwo() {
+        Customer john = new Customer("John P.", 15);
+        Customer sarah = new Customer("Sarah M.", 200);
+        Customer charles = new Customer("Charles B.", 150);
+        Customer mary = new Customer("Mary T.", 1);
+        List<Customer> customers = Arrays.asList(john, sarah, charles, mary);
+
+        List<Customer> customersWithMoreThan100Points = customers
+          .stream()
+          .filter(c -> c.getPoints() > 100)
+          .collect(Collectors.toList());
+
+        assertThat(customersWithMoreThan100Points).hasSize(2);
+        assertThat(customersWithMoreThan100Points).contains(sarah, charles);
+    }
+
+    @Test
+    public void givenListOfCustomers_whenFilterByPointsAndName_thenGetOne() {
+        Customer john = new Customer("John P.", 15);
+        Customer sarah = new Customer("Sarah M.", 200);
+        Customer charles = new Customer("Charles B.", 150);
+        Customer mary = new Customer("Mary T.", 1);
+        List<Customer> customers = Arrays.asList(john, sarah, charles, mary);
+
+        List<Customer> charlesWithMoreThan100Points = customers
+          .stream()
+          .filter(c -> c.getPoints() > 100 && c
+            .getName()
+            .startsWith("Charles"))
+          .collect(Collectors.toList());
+
+        assertThat(charlesWithMoreThan100Points).hasSize(1);
+        assertThat(charlesWithMoreThan100Points).contains(charles);
+    }
+
+    @Test
+    public void givenListOfCustomers_whenFilterByMethodReference_thenGetTwo() {
+        Customer john = new Customer("John P.", 15);
+        Customer sarah = new Customer("Sarah M.", 200);
+        Customer charles = new Customer("Charles B.", 150);
+        Customer mary = new Customer("Mary T.", 1);
+        List<Customer> customers = Arrays.asList(john, sarah, charles, mary);
+
+        List<Customer> customersWithMoreThan100Points = customers
+          .stream()
+          .filter(Customer::hasOverThousandPoints)
+          .collect(Collectors.toList());
+
+        assertThat(customersWithMoreThan100Points).hasSize(2);
+        assertThat(customersWithMoreThan100Points).contains(sarah, charles);
+    }
+
+    @Test
+    public void givenListOfCustomersWithOptional_whenFilterBy100Points_thenGetTwo() {
+        Optional<Customer> john = Optional.of(new Customer("John P.", 15));
+        Optional<Customer> sarah = Optional.of(new Customer("Sarah M.", 200));
+        Optional<Customer> mary = Optional.of(new Customer("Mary T.", 300));
+        List<Optional<Customer>> customers = Arrays.asList(john, sarah, Optional.empty(), mary, Optional.empty());
+
+        List<Customer> customersWithMoreThan100Points = customers
+          .stream()
+          .flatMap(c -> c
+            .map(Stream::of)
+            .orElseGet(Stream::empty))
+          .filter(Customer::hasOverThousandPoints)
+          .collect(Collectors.toList());
+
+        assertThat(customersWithMoreThan100Points).hasSize(2);
+        assertThat(customersWithMoreThan100Points).contains(sarah.get(), mary.get());
+    }
+
+    @Test
+    public void givenListOfCustomers_whenFilterWithCustomHandling_thenThrowException() {
+        Customer john = new Customer("John P.", 15, "https://images.unsplash.com/photo-1543320485-d0d5a49c2b2e");
+        Customer sarah = new Customer("Sarah M.", 200);
+        Customer charles = new Customer("Charles B.", 150);
+        Customer mary = new Customer("Mary T.", 1, "https://images.unsplash.com/photo-1543297057-25167dfc180e");
+        List<Customer> customers = Arrays.asList(john, sarah, charles, mary);
+
+        assertThatThrownBy(() -> customers
+          .stream()
+          .filter(Customer::hasValidProfilePhotoWithoutCheckedException)
+          .count()).isInstanceOf(RuntimeException.class);
+    }
+
+    @Test
+    public void givenListOfCustomers_whenFilterWithThrowingFunction_thenThrowException() {
+        Customer john = new Customer("John P.", 15, "https://images.unsplash.com/photo-1543320485-d0d5a49c2b2e");
+        Customer sarah = new Customer("Sarah M.", 200);
+        Customer charles = new Customer("Charles B.", 150);
+        Customer mary = new Customer("Mary T.", 1, "https://images.unsplash.com/photo-1543297057-25167dfc180e");
+        List<Customer> customers = Arrays.asList(john, sarah, charles, mary);
+
+        assertThatThrownBy(() -> customers
+          .stream()
+          .filter((ThrowingPredicate.unchecked(Customer::hasValidProfilePhoto)))
+          .collect(Collectors.toList())).isInstanceOf(WrappedException.class);
+    }
+
+    @Test
+    public void givenListOfCustomers_whenFilterWithTryCatch_thenGetTwo() {
+        Customer john = new Customer("John P.", 15, "https://images.unsplash.com/photo-1543320485-d0d5a49c2b2e");
+        Customer sarah = new Customer("Sarah M.", 200);
+        Customer charles = new Customer("Charles B.", 150);
+        Customer mary = new Customer("Mary T.", 1, "https://images.unsplash.com/photo-1543297057-25167dfc180e");
+        List<Customer> customers = Arrays.asList(john, sarah, charles, mary);
+
+        List<Customer> customersWithValidProfilePhoto = customers
+          .stream()
+          .filter(c -> {
+              try {
+                  return c.hasValidProfilePhoto();
+              } catch (IOException e) {
+                  //handle exception
+              }
+              return false;
+          })
+          .collect(Collectors.toList());
+
+        assertThat(customersWithValidProfilePhoto).hasSize(2);
+        assertThat(customersWithValidProfilePhoto).contains(john, mary);
+    }
+
+    @Test
+    public void givenListOfCustomers_whenFilterWithTryCatchAndRuntime_thenThrowException() {
+        List<Customer> customers = Arrays.asList(new Customer("John P.", 15, "https://images.unsplash.com/photo-1543320485-d0d5a49c2b2e"), new Customer("Sarah M.", 200), new Customer("Charles B.", 150),
+          new Customer("Mary T.", 1, "https://images.unsplash.com/photo-1543297057-25167dfc180e"));
+
+        assertThatThrownBy(() -> customers
+          .stream()
+          .filter(c -> {
+              try {
+                  return c.hasValidProfilePhoto();
+              } catch (IOException e) {
+                  throw new RuntimeException(e);
+              }
+          })
+          .collect(Collectors.toList())).isInstanceOf(RuntimeException.class);
+    }
+}

java-strings/README.md

@@ -39,3 +39,7 @@
 - [Generate a Secure Random Password in Java](https://www.baeldung.com/java-generate-secure-password)
 - [Removing Repeated Characters from a String](https://www.baeldung.com/java-remove-repeated-char)
 - [Join Array of Primitives with Separator in Java](https://www.baeldung.com/java-join-primitive-array)
+- [Convert String to Byte Array and Reverse in Java](https://www.baeldung.com/java-string-to-byte-array)
+- [Pad a String with Zeros or Spaces in Java](https://www.baeldung.com/java-pad-string)
+- [Adding a Newline Character to a String in Java](https://www.baeldung.com/java-string-newline)
+- [Remove or Replace part of a String in Java](https://www.baeldung.com/java-remove-replace-string-part)

java-strings/src/main/java/com/baeldung/string/SubstringPalindrome.java

@@ -0,0 +1,90 @@
+package com.baeldung.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;
+    }
+}

java-strings/src/test/java/com/baeldung/ConvertStringToListUnitTest.java

@@ -0,0 +1,135 @@
+package com.baeldung;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import org.apache.commons.lang3.StringUtils;
+import org.junit.Test;
+
+import com.google.common.base.Function;
+import com.google.common.base.Splitter;
+import com.google.common.collect.Lists;
+
+public class ConvertStringToListUnitTest {
+
+    private final String countries = "Russia,Germany,England,France,Italy";
+    private final String ranks = "1,2,3,4,5, 6,7";
+    private final String emptyStrings = ",,,,,";
+    private final List<String> expectedCountriesList = Arrays.asList("Russia", "Germany", "England", "France", "Italy");
+    private final List<Integer> expectedRanksList = Arrays.asList(1, 2, 3, 4, 5, 6, 7);
+    private final List<String> expectedEmptyStringsList = Arrays.asList("", "", "", "", "", "");
+
+    @Test
+    public void givenString_thenGetListOfStringByJava() {
+        List<String> convertedCountriesList = Arrays.asList(countries.split(",", -1));
+
+        assertEquals(expectedCountriesList, convertedCountriesList);
+    }
+
+    @Test
+    public void givenString_thenGetListOfStringByApache() {
+        List<String> convertedCountriesList = Arrays.asList(StringUtils.splitPreserveAllTokens(countries, ","));
+
+        assertEquals(expectedCountriesList, convertedCountriesList);
+    }
+
+    @Test
+    public void givenString_thenGetListOfStringByGuava() {
+        List<String> convertedCountriesList = Splitter.on(",")
+            .trimResults()
+            .splitToList(countries);
+
+        assertEquals(expectedCountriesList, convertedCountriesList);
+    }
+
+    @Test
+    public void givenString_thenGetListOfStringByJava8() {
+        List<String> convertedCountriesList = Stream.of(countries.split(",", -1))
+            .collect(Collectors.toList());
+
+        assertEquals(expectedCountriesList, convertedCountriesList);
+    }
+
+    @Test
+    public void givenString_thenGetListOfIntegerByJava() {
+        String[] convertedRankArray = ranks.split(",");
+        List<Integer> convertedRankList = new ArrayList<Integer>();
+        for (String number : convertedRankArray) {
+            convertedRankList.add(Integer.parseInt(number.trim()));
+        }
+
+        assertEquals(expectedRanksList, convertedRankList);
+    }
+
+    @Test
+    public void givenString_thenGetListOfIntegerByGuava() {
+        List<Integer> convertedRankList = Lists.transform(Splitter.on(",")
+            .trimResults()
+            .splitToList(ranks), new Function<String, Integer>() {
+                @Override
+                public Integer apply(String input) {
+                    return Integer.parseInt(input.trim());
+                }
+            });
+
+        assertEquals(expectedRanksList, convertedRankList);
+    }
+
+    @Test
+    public void givenString_thenGetListOfIntegerByJava8() {
+        List<Integer> convertedRankList = Stream.of(ranks.split(","))
+            .map(String::trim)
+            .map(Integer::parseInt)
+            .collect(Collectors.toList());
+
+        assertEquals(expectedRanksList, convertedRankList);
+    }
+
+    @Test
+    public void givenString_thenGetListOfIntegerByApache() {
+        String[] convertedRankArray = StringUtils.split(ranks, ",");
+        List<Integer> convertedRankList = new ArrayList<Integer>();
+        for (String number : convertedRankArray) {
+            convertedRankList.add(Integer.parseInt(number.trim()));
+        }
+
+        assertEquals(expectedRanksList, convertedRankList);
+    }
+
+    @Test
+    public void givenEmptyStrings_thenGetListOfStringByJava() {
+        List<String> convertedEmptyStringsList = Arrays.asList(emptyStrings.split(",", -1));
+
+        assertEquals(expectedEmptyStringsList, convertedEmptyStringsList);
+    }
+
+    @Test
+    public void givenEmptyStrings_thenGetListOfStringByApache() {
+        List<String> convertedEmptyStringsList = Arrays.asList(StringUtils.splitPreserveAllTokens(emptyStrings, ","));
+
+        assertEquals(expectedEmptyStringsList, convertedEmptyStringsList);
+    }
+
+    @Test
+    public void givenEmptyStrings_thenGetListOfStringByGuava() {
+        List<String> convertedEmptyStringsList = Splitter.on(",")
+            .trimResults()
+            .splitToList(emptyStrings);
+
+        assertEquals(expectedEmptyStringsList, convertedEmptyStringsList);
+    }
+
+    @Test
+    public void givenEmptyStrings_thenGetListOfStringByJava8() {
+        List<String> convertedEmptyStringsList = Stream.of(emptyStrings.split(",", -1))
+            .collect(Collectors.toList());
+
+        assertEquals(expectedEmptyStringsList, convertedEmptyStringsList);
+    }
+
+}

java-strings/src/test/java/com/baeldung/string/SubstringPalindromeUnitTest.java

@@ -0,0 +1,83 @@
+package com.baeldung.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));
+    }
+}

json/pom.xml

@@ -33,6 +33,16 @@
             <groupId>org.json</groupId>
             <artifactId>json</artifactId>
             <version>20171018</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.code.gson</groupId>
+            <artifactId>gson</artifactId>
+            <version>2.8.5</version>
+        </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>2.9.7</version>
         </dependency>
 		<dependency>
             <groupId>javax.json.bind</groupId>

json/src/main/java/com/baeldung/escape/JsonEscape.java

@@ -0,0 +1,41 @@
+package com.baeldung.escape;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.gson.JsonObject;
+import org.json.JSONObject;
+
+class JsonEscape {
+
+    String escapeJson(String input) {
+        JSONObject jsonObject = new JSONObject();
+        jsonObject.put("message", input);
+        return jsonObject.toString();
+    }
+
+    String escapeGson(String input) {
+        JsonObject gsonObject = new JsonObject();
+        gsonObject.addProperty("message", input);
+        return gsonObject.toString();
+    }
+
+    String escapeJackson(String input) throws JsonProcessingException {
+        return new ObjectMapper().writeValueAsString(new Payload(input));
+    }
+
+    static class Payload {
+        String message;
+
+        Payload(String message) {
+            this.message = message;
+        }
+
+        public String getMessage() {
+            return message;
+        }
+
+        public void setMessage(String message) {
+            this.message = message;
+        }
+    }
+}

json/src/test/java/com/baeldung/escape/JsonEscapeUnitTest.java

@@ -0,0 +1,36 @@
+package com.baeldung.escape;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class JsonEscapeUnitTest {
+
+    private JsonEscape testedInstance;
+    private static final String EXPECTED = "{\"message\":\"Hello \\\"World\\\"\"}";
+
+    @BeforeEach
+    void setUp() {
+        testedInstance = new JsonEscape();
+    }
+
+    @Test
+    void escapeJson() {
+        String actual = testedInstance.escapeJson("Hello \"World\"");
+        assertEquals(EXPECTED, actual);
+    }
+
+    @Test
+    void escapeGson() {
+        String actual = testedInstance.escapeGson("Hello \"World\"");
+        assertEquals(EXPECTED, actual);
+    }
+
+    @Test
+    void escapeJackson() throws JsonProcessingException {
+        String actual = testedInstance.escapeJackson("Hello \"World\"");
+        assertEquals(EXPECTED, actual);
+    }
+}

kotlin-libraries/README.md

@@ -8,3 +8,4 @@
 - [Kotlin with Ktor](http://www.baeldung.com/kotlin-ktor)
 - [Guide to the Kotlin Exposed Framework](https://www.baeldung.com/kotlin-exposed-persistence)
 - [Working with Dates in Kotlin](https://www.baeldung.com/kotlin-dates)
+- [Introduction to Arrow in Kotlin](https://www.baeldung.com/kotlin-arrow)

libraries-data/README.md

@@ -14,3 +14,4 @@
 - [Building a Data Pipeline with Flink and Kafka](https://www.baeldung.com/kafka-flink-data-pipeline)
 - [Intro to Apache Storm](https://www.baeldung.com/apache-storm)
 - [Guide to Ebean ORM](https://www.baeldung.com/ebean-orm)
+- [Introduction to Kafka Connectors](https://www.baeldung.com/kafka-connectors-guide)

libraries/pom.xml

@@ -717,6 +717,12 @@
             <version>${suanshu.version}</version>
         </dependency>
 
+        <dependency>
+            <groupId>org.derive4j</groupId>
+            <artifactId>derive4j</artifactId>
+            <version>${derive4j.version}</version>
+            <optional>true</optional>
+        </dependency>
     </dependencies>
 
     <repositories>
@@ -942,7 +948,7 @@
         <yarg.version>2.0.4</yarg.version>
         <mbassador.version>1.3.1</mbassador.version>
         <jdeferred.version>1.2.6</jdeferred.version>
-        <functionaljava.version>4.7</functionaljava.version>
+        <functionaljava.version>4.8.1</functionaljava.version>
         <jgrapht.version>1.0.1</jgrapht.version>
         <docx4j.version>3.3.5</docx4j.version>
         <jaxb-api.version>2.1</jaxb-api.version>
@@ -952,6 +958,7 @@
         <fugue.version>4.5.1</fugue.version>
         <maven-bundle-plugin.version>3.3.0</maven-bundle-plugin.version>
         <maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
+        <derive4j.version>1.1.0</derive4j.version>
     </properties>
 
 </project>

libraries/src/main/java/com/baeldung/derive4j/adt/Either.java

@@ -0,0 +1,10 @@
+package com.baeldung.derive4j.adt;
+
+import org.derive4j.Data;
+
+import java.util.function.Function;
+
+@Data
+interface Either<A,B>{
+    <X> X match(Function<A, X> left, Function<B, X> right);
+}

libraries/src/main/java/com/baeldung/derive4j/lazy/LazyRequest.java

@@ -0,0 +1,21 @@
+package com.baeldung.derive4j.lazy;
+
+import org.derive4j.Data;
+import org.derive4j.Derive;
+import org.derive4j.Make;
+
+@Data(value = @Derive(
+    inClass = "{ClassName}Impl",
+    make = {Make.lazyConstructor, Make.constructors}
+))
+public interface LazyRequest {
+    interface Cases<R>{
+        R GET(String path);
+        R POST(String path, String body);
+        R PUT(String path, String body);
+        R DELETE(String path);
+    }
+
+    <R> R match(LazyRequest.Cases<R> method);
+}
+

libraries/src/main/java/com/baeldung/derive4j/pattern/HTTPRequest.java

@@ -0,0 +1,15 @@
+package com.baeldung.derive4j.pattern;
+
+import org.derive4j.Data;
+
+@Data
+interface HTTPRequest {
+    interface Cases<R>{
+        R GET(String path);
+        R POST(String path, String body);
+        R PUT(String path, String body);
+        R DELETE(String path);
+    }
+
+     <R> R match(Cases<R> method);
+}

libraries/src/main/java/com/baeldung/derive4j/pattern/HTTPResponse.java

@@ -0,0 +1,19 @@
+package com.baeldung.derive4j.pattern;
+
+public class HTTPResponse {
+    private int  statusCode;
+    private String responseBody;
+
+    public int getStatusCode() {
+        return statusCode;
+    }
+
+    public String getResponseBody() {
+        return responseBody;
+    }
+
+    public HTTPResponse(int statusCode, String responseBody) {
+        this.statusCode = statusCode;
+        this.responseBody = responseBody;
+    }
+}

libraries/src/main/java/com/baeldung/derive4j/pattern/HTTPServer.java

@@ -0,0 +1,17 @@
+package com.baeldung.derive4j.pattern;
+
+
+public class HTTPServer {
+    public static String GET_RESPONSE_BODY = "Success!";
+    public static String PUT_RESPONSE_BODY = "Resource Created!";
+    public static String POST_RESPONSE_BODY = "Resource Updated!";
+    public static String DELETE_RESPONSE_BODY = "Resource Deleted!";
+
+    public HTTPResponse acceptRequest(HTTPRequest request) {
+       return HTTPRequests.caseOf(request)
+                .GET((path) -> new HTTPResponse(200, GET_RESPONSE_BODY))
+                .POST((path,body) -> new HTTPResponse(201, POST_RESPONSE_BODY))
+                .PUT((path,body) -> new HTTPResponse(200, PUT_RESPONSE_BODY))
+                .DELETE(path -> new HTTPResponse(200, DELETE_RESPONSE_BODY));
+    }
+}

libraries/src/test/java/com/baeldung/derive4j/adt/EitherUnitTest.java

@@ -0,0 +1,33 @@
+package com.baeldung.derive4j.adt;
+
+import org.assertj.core.api.Assertions;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mockito;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.util.Optional;
+import java.util.function.Function;
+@RunWith(MockitoJUnitRunner.class)
+public class EitherUnitTest {
+    @Test
+    public void testEitherIsCreatedFromRight() {
+       Either<Exception, String> either = Eithers.right("Okay");
+       Optional<Exception> leftOptional = Eithers.getLeft(either);
+       Optional<String> rightOptional = Eithers.getRight(either);
+       Assertions.assertThat(leftOptional).isEmpty();
+       Assertions.assertThat(rightOptional).hasValue("Okay");
+
+    }
+
+    @Test
+    public void testEitherIsMatchedWithRight() {
+        Either<Exception, String> either = Eithers.right("Okay");
+        Function<Exception, String> leftFunction = Mockito.mock(Function.class);
+        Function<String, String> rightFunction = Mockito.mock(Function.class);
+        either.match(leftFunction, rightFunction);
+        Mockito.verify(rightFunction, Mockito.times(1)).apply("Okay");
+        Mockito.verify(leftFunction, Mockito.times(0)).apply(Mockito.any(Exception.class));
+    }
+
+}

libraries/src/test/java/com/baeldung/derive4j/lazy/LazyRequestUnitTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.derive4j.lazy;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.mockito.Mockito;
+
+import java.util.function.Supplier;
+
+public class LazyRequestUnitTest {
+
+    @Test
+    public void givenLazyContstructedRequest_whenRequestIsReferenced_thenRequestIsLazilyContructed() {
+        LazyRequestSupplier mockSupplier = Mockito.spy(new LazyRequestSupplier());
+
+        LazyRequest request = LazyRequestImpl.lazy(() -> mockSupplier.get());
+        Mockito.verify(mockSupplier, Mockito.times(0)).get();
+        Assert.assertEquals(LazyRequestImpl.getPath(request), "http://test.com/get");
+        Mockito.verify(mockSupplier, Mockito.times(1)).get();
+
+    }
+
+    class LazyRequestSupplier implements Supplier<LazyRequest> {
+        @Override
+        public LazyRequest get() {
+            return LazyRequestImpl.GET("http://test.com/get");
+        }
+    }
+}

libraries/src/test/java/com/baeldung/derive4j/pattern/HTTPRequestUnitTest.java

@@ -0,0 +1,22 @@
+package com.baeldung.derive4j.pattern;
+
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class HTTPRequestUnitTest {
+    public static HTTPServer server;
+
+    @BeforeClass
+    public static void setUp() {
+        server = new HTTPServer();
+    }
+
+    @Test
+    public void givenHttpGETRequest_whenRequestReachesServer_thenProperResponseIsReturned() {
+        HTTPRequest postRequest = HTTPRequests.POST("http://test.com/post", "Resource");
+        HTTPResponse response = server.acceptRequest(postRequest);
+        Assert.assertEquals(201, response.getStatusCode());
+        Assert.assertEquals(HTTPServer.POST_RESPONSE_BODY, response.getResponseBody());
+    }
+}

libraries/src/test/java/com/baeldung/fj/FunctionalJavaUnitTest.java

@@ -1,79 +1,116 @@
-package com.baeldung.fj;
-
-import static org.junit.Assert.assertEquals;
-
-import org.junit.Test;
-
-import fj.F;
-import fj.data.Array;
-import fj.data.List;
-import fj.data.Option;
-import fj.function.Characters;
-import fj.function.Integers;
-
-public class FunctionalJavaUnitTest {
-
-    public static final F<Integer, Boolean> isEven = i -> i % 2 == 0;
-
-    @Test
-    public void calculateEvenNumbers_givenIntList_returnTrue() {
-        List<Integer> fList = List.list(3, 4, 5, 6);
-        List<Boolean> evenList = fList.map(isEven);
-        List<Boolean> evenListTrueResult = List.list(false, true, false, true);
-        List<Boolean> evenListFalseResult = List.list(true, false, false, true);
-        assertEquals(evenList.equals(evenListTrueResult), true);
-        assertEquals(evenList.equals(evenListFalseResult), false);
-    }
-
-    @Test
-    public void mapList_givenIntList_returnResult() {
-        List<Integer> fList = List.list(3, 4, 5, 6);
-        fList = fList.map(i -> i + 100);
-        List<Integer> resultList = List.list(103, 104, 105, 106);
-        List<Integer> falseResultList = List.list(15, 504, 105, 106);
-        assertEquals(fList.equals(resultList), true);
-        assertEquals(fList.equals(falseResultList), false);
-    }
-
-    @Test
-    public void filterList_givenIntList_returnResult() {
-        Array<Integer> array = Array.array(3, 4, 5, 6);
-        Array<Integer> filteredArray = array.filter(Integers.even);
-        Array<Integer> result = Array.array(4, 6);
-        Array<Integer> wrongResult = Array.array(3, 5);
-        assertEquals(filteredArray.equals(result), true);
-        assertEquals(filteredArray.equals(wrongResult), false);
-    }
-
-    @Test
-    public void checkForLowerCase_givenStringArray_returnResult() {
-        Array<String> array = Array.array("Welcome", "To", "baeldung");
-        Array<String> array2 = Array.array("Welcome", "To", "Baeldung");
-        Boolean isExist = array.exists(s -> List.fromString(s).forall(Characters.isLowerCase));
-        Boolean isExist2 = array2.exists(s -> List.fromString(s).forall(Characters.isLowerCase));
-        assertEquals(isExist, true);
-        assertEquals(isExist2, false);
-    }
-
-    @Test
-    public void checkOptions_givenOptions_returnResult() {
-        Option<Integer> n1 = Option.some(1);
-        Option<Integer> n2 = Option.some(2);
-
-        F<Integer, Option<Integer>> f1 = i -> i % 2 == 0 ? Option.some(i + 100) : Option.none();
-
-        Option<Integer> result1 = n1.bind(f1);
-        Option<Integer> result2 = n2.bind(f1);
-
-        assertEquals(result1, Option.none());
-        assertEquals(result2, Option.some(102));
-    }
-
-    @Test
-    public void foldLeft_givenArray_returnResult() {
-        Array<Integer> intArray = Array.array(17, 44, 67, 2, 22, 80, 1, 27);
-        int sum = intArray.foldLeft(Integers.add, 0);
-        assertEquals(sum, 260);
-    }
-
-}
+package com.baeldung.fj;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+import fj.F;
+import fj.Show;
+import fj.data.Array;
+import fj.data.List;
+import fj.data.Option;
+import fj.function.Characters;
+import fj.function.Integers;
+
+public class FunctionalJavaUnitTest {
+
+    public static final F<Integer, Boolean> isEven = i -> i % 2 == 0;
+
+    public static final Integer timesTwoRegular(Integer i) {
+        return i * 2;
+    }
+
+    public static final F<Integer, Integer> timesTwo = i -> i * 2;
+
+    public static final F<Integer, Integer> plusOne = i -> i + 1;
+
+    @Test
+    public void multiplyNumbers_givenIntList_returnTrue() {
+        List<Integer> fList = List.list(1, 2, 3, 4);
+        List<Integer> fList1 = fList.map(timesTwo);
+        List<Integer> fList2 = fList.map(i -> i * 2);
+
+        assertTrue(fList1.equals(fList2));
+    }
+
+    @Test
+    public void applyMultipleFunctions_givenIntList_returnFalse() {
+        List<Integer> fList = List.list(1, 2, 3, 4);
+        List<Integer> fList1 = fList.map(timesTwo).map(plusOne);
+        Show.listShow(Show.intShow).println(fList1);
+        List<Integer> fList2 = fList.map(plusOne).map(timesTwo);
+        Show.listShow(Show.intShow).println(fList2);
+
+        assertFalse(fList1.equals(fList2));
+    }
+
+    @Test
+    public void calculateEvenNumbers_givenIntList_returnTrue() {
+        List<Integer> fList = List.list(3, 4, 5, 6);
+        List<Boolean> evenList = fList.map(isEven);
+        List<Boolean> evenListTrueResult = List.list(false, true, false, true);
+
+        assertTrue(evenList.equals(evenListTrueResult));
+    }
+
+    @Test
+    public void mapList_givenIntList_returnResult() {
+        List<Integer> fList = List.list(3, 4, 5, 6);
+        fList = fList.map(i -> i + 100);
+        List<Integer> resultList = List.list(103, 104, 105, 106);
+
+        assertTrue(fList.equals(resultList));
+    }
+
+    @Test
+    public void filterList_givenIntList_returnResult() {
+        Array<Integer> array = Array.array(3, 4, 5, 6);
+        Array<Integer> filteredArray = array.filter(isEven);
+        Array<Integer> result = Array.array(4, 6);
+
+        assertTrue(filteredArray.equals(result));
+    }
+
+    @Test
+    public void checkForLowerCase_givenStringArray_returnResult() {
+        Array<String> array = Array.array("Welcome", "To", "baeldung");
+        assertTrue(array.exists(s -> List.fromString(s).forall(Characters.isLowerCase)));
+ 
+        Array<String> array2 = Array.array("Welcome", "To", "Baeldung");
+        assertFalse(array2.exists(s -> List.fromString(s).forall(Characters.isLowerCase)));
+ 
+        assertFalse(array.forall(s -> List.fromString(s).forall(Characters.isLowerCase)));
+    }
+
+    @Test
+    public void checkOptions_givenOptions_returnResult() {
+        Option<Integer> n1 = Option.some(1);
+        Option<Integer> n2 = Option.some(2);
+        Option<Integer> n3 = Option.none();
+
+        F<Integer, Option<Integer>> function = i -> i % 2 == 0 ? Option.some(i + 100) : Option.none();
+
+        Option<Integer> result1 = n1.bind(function);
+        Option<Integer> result2 = n2.bind(function);
+        Option<Integer> result3 = n3.bind(function);
+
+        assertEquals(Option.none(), result1);
+        assertEquals(Option.some(102), result2);
+        assertEquals(Option.none(), result3);
+    }
+
+    @Test
+    public void foldLeft_givenArray_returnResult() {
+        Array<Integer> intArray = Array.array(17, 44, 67, 2, 22, 80, 1, 27);
+        int sumAll = intArray.foldLeft(Integers.add, 0);
+
+        assertEquals(260, sumAll);
+
+        int sumEven = intArray.filter(isEven).foldLeft(Integers.add, 0);
+
+        assertEquals(148, sumEven);
+    }
+    
+}

micronaut/pom.xml

@@ -7,15 +7,10 @@
   
   <properties>
     <exec.mainClass>com.baeldung.micronaut.helloworld.server.ServerApplication</exec.mainClass>
-    <micronaut.version>1.0.0.M2</micronaut.version>
-    <jdk.version>9</jdk.version>
+    <micronaut.version>1.0.0.RC2</micronaut.version>
+    <jdk.version>1.8</jdk.version>
   </properties>
-  <repositories>
-        <repository>
-          <id>jcenter.bintray.com</id>
-          <url>http://jcenter.bintray.com</url>
-        </repository>
-    </repositories>
+
   <dependencyManagement>
     <dependencies>
       <dependency>

micronaut/src/main/java/com/baeldung/micronaut/helloworld/client/ConcreteGreetingClient.java

@@ -1,7 +1,7 @@
 package com.baeldung.micronaut.helloworld.client;
 
 import io.micronaut.http.HttpRequest;
-import io.micronaut.http.client.Client;
+import io.micronaut.http.client.annotation.Client;
 import io.micronaut.http.client.RxHttpClient;
 import io.reactivex.Single;
 

micronaut/src/main/java/com/baeldung/micronaut/helloworld/client/GreetingClient.java

@@ -1,10 +1,7 @@
 package com.baeldung.micronaut.helloworld.client;
 
 import io.micronaut.http.annotation.Get;
-import io.micronaut.http.client.Client;
-import io.micronaut.http.client.RxHttpClient;
-
-import javax.inject.Inject;
+import io.micronaut.http.client.annotation.Client;
 
 @Client("/greet")
 public interface GreetingClient {

parent-boot-2.0-temp/README.md

@@ -0,0 +1,2 @@
+This pom will be ued only temporary until we migrate parent-boot-2 to 2.1.0 for ticket BAEL-10354
+

parent-boot-2.0-temp/pom.xml

@@ -0,0 +1,85 @@
+<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>parent-boot-2.0-temp</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <packaging>pom</packaging>
+    <description>Temporary Parent for all Spring Boot 2.0.x modules</description>
+    <!-- This pom will be ued only temporary until we migrate parent-boot-2 to 2.1.0 for ticket BAEL-10354 -->
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+	<dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+                <version>${spring-boot.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
+    <dependencies>
+        <dependency>
+            <groupId>io.rest-assured</groupId>
+            <artifactId>rest-assured</artifactId>
+            </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+	<build>
+		<pluginManagement>
+			<plugins>
+				<plugin>
+					<groupId>org.springframework.boot</groupId>
+					<artifactId>spring-boot-maven-plugin</artifactId>
+					<version>${spring-boot.version}</version>
+					<configuration>
+						<mainClass>${start-class}</mainClass>
+						<!-- this is necessary as we're not using the Boot parent -->
+					</configuration>
+				</plugin>
+			</plugins>
+		</pluginManagement>
+	</build>
+	
+    <profiles>
+        <profile>
+            <id>thin-jar</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.springframework.boot</groupId>
+                        <artifactId>spring-boot-maven-plugin</artifactId>
+                        <dependencies>
+                            <!-- The following enables the "thin jar" deployment option. -->
+                            <dependency>
+                                <groupId>org.springframework.boot.experimental</groupId>
+                                <artifactId>spring-boot-thin-layout</artifactId>
+                                <version>${thin.version}</version>
+                            </dependency>
+                        </dependencies>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+
+    <properties>
+        <rest-assured.version>3.1.0</rest-assured.version>
+        <!-- plugins -->
+        <thin.version>1.0.11.RELEASE</thin.version>
+        <spring-boot.version>2.0.5.RELEASE</spring-boot.version>
+    </properties>
+</project>
+
+

parent-boot-2/pom.xml

@@ -78,7 +78,7 @@
         <rest-assured.version>3.1.0</rest-assured.version>
         <!-- plugins -->
         <thin.version>1.0.11.RELEASE</thin.version>
-        <spring-boot.version>2.0.5.RELEASE</spring-boot.version>
+        <spring-boot.version>2.1.1.RELEASE</spring-boot.version>
     </properties>
 </project>
 

persistence-modules/README.md

@@ -10,3 +10,4 @@
 - [A Guide to Jdbi](http://www.baeldung.com/jdbi)
 - [Pessimistic Locking in JPA](http://www.baeldung.com/jpa-pessimistic-locking)
 - [Get All Data from a Table with Hibernate](https://www.baeldung.com/hibernate-select-all)
+- [Spring Data with Reactive Cassandra](https://www.baeldung.com/spring-data-cassandra-reactive)

persistence-modules/hibernate5/README.md

@@ -19,3 +19,5 @@
 - [Hibernate 5 Naming Strategy Configuration](https://www.baeldung.com/hibernate-naming-strategy)
 - [Proxy in Hibernate load() Method](https://www.baeldung.com/hibernate-proxy-load-method)
 - [Custom Types in Hibernate](https://www.baeldung.com/hibernate-custom-types)
+- [Criteria API – An Example of IN Expressions](https://www.baeldung.com/jpa-criteria-api-in-expressions)
+- [Difference Between @JoinColumn and mappedBy](https://www.baeldung.com/jpa-joincolumn-vs-mappedby)

persistence-modules/hibernate5/pom.xml

@@ -51,6 +51,11 @@
             <artifactId>hibernate-testing</artifactId>
             <version>5.2.2.Final</version>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.core</groupId>
+            <artifactId>jackson-databind</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
     </dependencies>
 
     <build>
@@ -69,6 +74,7 @@
         <mariaDB4j.version>2.2.3</mariaDB4j.version>
         <h2database.version>1.4.196</h2database.version>
         <assertj-core.version>3.8.0</assertj-core.version>
+        <jackson.version>2.8.11.3</jackson.version>
     </properties>
 
 </project>

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/entities/DeptEmployee.java

@@ -1,7 +1,17 @@
 package com.baeldung.hibernate.entities;
 
-import javax.persistence.*;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
 
+@org.hibernate.annotations.NamedQueries({ @org.hibernate.annotations.NamedQuery(name = "DeptEmployee_FindByEmployeeNumber", query = "from DeptEmployee where employeeNumber = :employeeNo"),
+        @org.hibernate.annotations.NamedQuery(name = "DeptEmployee_FindAllByDesgination", query = "from DeptEmployee where designation = :designation"),
+        @org.hibernate.annotations.NamedQuery(name = "DeptEmployee_UpdateEmployeeDepartment", query = "Update DeptEmployee set department = :newDepartment where employeeNumber = :employeeNo"),
+        @org.hibernate.annotations.NamedQuery(name = "DeptEmployee_FindAllByDepartment", query = "from DeptEmployee where department = :department", timeout = 1, fetchSize = 10) })
+@org.hibernate.annotations.NamedNativeQueries({ @org.hibernate.annotations.NamedNativeQuery(name = "DeptEmployee_FindByEmployeeName", query = "select * from deptemployee emp where name=:name", resultClass = DeptEmployee.class),
+        @org.hibernate.annotations.NamedNativeQuery(name = "DeptEmployee_UpdateEmployeeDesignation", query = "call UPDATE_EMPLOYEE_DESIGNATION(:employeeNumber, :newDesignation)", resultClass = DeptEmployee.class) })
 @Entity
 public class DeptEmployee {
     @Id
@@ -16,7 +26,7 @@ public class DeptEmployee {
 
     @ManyToOne
     private Department department;
-    
+
     public DeptEmployee(String name, String employeeNumber, Department department) {
         this.name = name;
         this.employeeNumber = employeeNumber;

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/onetoone/HibernateUtil.java

@@ -0,0 +1,66 @@
+package com.baeldung.hibernate.onetoone;
+
+import com.baeldung.hibernate.customtypes.LocalDateStringType;
+import org.hibernate.SessionFactory;
+import org.hibernate.boot.Metadata;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.service.ServiceRegistry;
+
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.net.URL;
+import java.util.Properties;
+
+public class HibernateUtil {
+    private static SessionFactory sessionFactory;
+
+    private HibernateUtil() {
+    }
+
+    public static SessionFactory getSessionFactory(Strategy strategy) {
+        if (sessionFactory == null) {
+            sessionFactory = buildSessionFactory(strategy);
+        }
+        return sessionFactory;
+    }
+
+    private static SessionFactory buildSessionFactory(Strategy strategy) {
+        try {
+            ServiceRegistry serviceRegistry = configureServiceRegistry();
+
+            MetadataSources metadataSources = new MetadataSources(serviceRegistry);
+
+            for (Class<?> entityClass : strategy.getEntityClasses()) {
+                metadataSources.addAnnotatedClass(entityClass);
+            }
+
+            Metadata metadata = metadataSources.getMetadataBuilder()
+                    .applyBasicType(LocalDateStringType.INSTANCE)
+                    .build();
+
+            return metadata.getSessionFactoryBuilder()
+                    .build();
+        } catch (IOException ex) {
+            throw new ExceptionInInitializerError(ex);
+        }
+    }
+
+
+    private static ServiceRegistry configureServiceRegistry() throws IOException {
+        Properties properties = getProperties();
+        return new StandardServiceRegistryBuilder().applySettings(properties)
+                .build();
+    }
+
+    private static Properties getProperties() throws IOException {
+        Properties properties = new Properties();
+        URL propertiesURL = Thread.currentThread()
+                .getContextClassLoader()
+                .getResource("hibernate.properties");
+        try (FileInputStream inputStream = new FileInputStream(propertiesURL.getFile())) {
+            properties.load(inputStream);
+        }
+        return properties;
+    }
+}

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/onetoone/foreignkeybased/User.java

@@ -22,7 +22,7 @@ public class User {
     private String userName;
 
     @OneToOne(cascade = CascadeType.ALL)
-     @JoinColumn(name = "address_id", referencedColumnName = "id")
+    @JoinColumn(name = "address_id", referencedColumnName = "id")
     private Address address;
 
     public Long getId() {

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/operations/HibernateOperations.java

@@ -0,0 +1,114 @@
+package com.baeldung.hibernate.operations;
+
+import java.util.List;
+
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
+import javax.persistence.Persistence;
+
+import com.baeldung.hibernate.pojo.Movie;
+
+/**
+ * 
+ *Class to illustrate the usage of EntityManager API.
+ */
+public class HibernateOperations {
+
+    private static final EntityManagerFactory emf;
+
+    /**
+     * Static block for creating EntityManagerFactory. The Persistence class looks for META-INF/persistence.xml in the classpath.
+     */
+    static {
+        emf = Persistence.createEntityManagerFactory("com.baeldung.movie_catalog");
+    }
+
+    /**
+     * Static method returning EntityManager.
+     * @return EntityManager
+     */
+    public static EntityManager getEntityManager() {
+        return emf.createEntityManager();
+    }
+
+    /**
+     * Saves the movie entity into the database. Here we are using Application Managed EntityManager, hence should handle transactions by ourselves.
+     */
+    public void saveMovie() {
+        EntityManager em = HibernateOperations.getEntityManager();
+        em.getTransaction()
+            .begin();
+        Movie movie = new Movie();
+        movie.setId(1L);
+        movie.setMovieName("The Godfather");
+        movie.setReleaseYear(1972);
+        movie.setLanguage("English");
+        em.persist(movie);
+        em.getTransaction()
+            .commit();
+    }
+
+    /**
+     * Method to illustrate the querying support in EntityManager when the result is a single object.
+     * @return Movie
+     */
+    public Movie queryForMovieById() {
+        EntityManager em = HibernateOperations.getEntityManager();
+        Movie movie = (Movie) em.createQuery("SELECT movie from Movie movie where movie.id = ?1")
+            .setParameter(1, new Long(1L))
+            .getSingleResult();
+        return movie;
+    }
+
+    /**
+     * Method to illustrate the querying support in EntityManager when the result is a list.
+     * @return
+     */
+    public List<?> queryForMovies() {
+        EntityManager em = HibernateOperations.getEntityManager();
+        List<?> movies = em.createQuery("SELECT movie from Movie movie where movie.language = ?1")
+            .setParameter(1, "English")
+            .getResultList();
+        return movies;
+    }
+
+    /**
+     * Method to illustrate the usage of find() method.
+     * @param movieId
+     * @return Movie
+     */
+    public Movie getMovie(Long movieId) {
+        EntityManager em = HibernateOperations.getEntityManager();
+        Movie movie = em.find(Movie.class, new Long(movieId));
+        return movie;
+    }
+
+    /**
+     * Method to illustrate the usage of merge() function.
+     */
+    public void mergeMovie() {
+        EntityManager em = HibernateOperations.getEntityManager();
+        Movie movie = getMovie(1L);
+        em.detach(movie);
+        movie.setLanguage("Italian");
+        em.getTransaction()
+            .begin();
+        em.merge(movie);
+        em.getTransaction()
+            .commit();
+    }
+
+    /**
+     * Method to illustrate the usage of remove() function.
+     */
+    public void removeMovie() {
+        EntityManager em = HibernateOperations.getEntityManager();
+        em.getTransaction()
+            .begin();
+        Movie movie = em.find(Movie.class, new Long(1L));
+        em.remove(movie);
+        em.getTransaction()
+            .commit();
+    }
+
+}

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/persistjson/Customer.java

@@ -0,0 +1,80 @@
+package com.baeldung.hibernate.persistjson;
+
+import java.io.IOException;
+import java.util.Map;
+
+import javax.persistence.Convert;
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+@Entity
+@Table(name = "Customers")
+public class Customer {
+
+    @Id
+    private int id;
+
+    private String firstName;
+
+    private String lastName;
+
+    private String customerAttributeJSON;
+
+    @Convert(converter = HashMapConverter.class)
+    private Map<String, Object> customerAttributes;
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(int id) {
+        this.id = id;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+
+    public String getCustomerAttributeJSON() {
+        return customerAttributeJSON;
+    }
+
+    public void setCustomerAttributeJSON(String customerAttributeJSON) {
+        this.customerAttributeJSON = customerAttributeJSON;
+    }
+
+    public Map<String, Object> getCustomerAttributes() {
+        return customerAttributes;
+    }
+
+    public void setCustomerAttributes(Map<String, Object> customerAttributes) {
+        this.customerAttributes = customerAttributes;
+    }
+
+    private static final ObjectMapper objectMapper = new ObjectMapper();
+
+    public void serializeCustomerAttributes() throws JsonProcessingException {
+        this.customerAttributeJSON = objectMapper.writeValueAsString(customerAttributes);
+    }
+
+    public void deserializeCustomerAttributes() throws IOException {
+        this.customerAttributes = objectMapper.readValue(customerAttributeJSON, Map.class);
+    }
+
+}

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/persistjson/HashMapConverter.java

@@ -0,0 +1,47 @@
+package com.baeldung.hibernate.persistjson;
+
+import java.io.IOException;
+import java.util.Map;
+
+import javax.persistence.AttributeConverter;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.baeldung.hibernate.interceptors.CustomInterceptor;
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+public class HashMapConverter implements AttributeConverter<Map<String, Object>, String> {
+
+    private static final Logger logger = LoggerFactory.getLogger(CustomInterceptor.class);
+
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
+    @Override
+    public String convertToDatabaseColumn(Map<String, Object> customerInfo) {
+
+        String customerInfoJson = null;
+        try {
+            customerInfoJson = objectMapper.writeValueAsString(customerInfo);
+        } catch (final JsonProcessingException e) {
+            logger.error("JSON writing error", e);
+        }
+
+        return customerInfoJson;
+    }
+
+    @Override
+    public Map<String, Object> convertToEntityAttribute(String customerInfoJSON) {
+
+        Map<String, Object> customerInfo = null;
+        try {
+            customerInfo = objectMapper.readValue(customerInfoJSON, Map.class);
+        } catch (final IOException e) {
+            logger.error("JSON reading error", e);
+        }
+
+        return customerInfo;
+    }
+
+}

persistence-modules/hibernate5/src/main/java/com/baeldung/hibernate/pojo/Movie.java

@@ -0,0 +1,52 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "MOVIE")
+public class Movie {
+
+    @Id
+    private Long id;
+
+    private String movieName;
+
+    private Integer releaseYear;
+
+    private String language;
+
+    public String getMovieName() {
+        return movieName;
+    }
+
+    public void setMovieName(String movieName) {
+        this.movieName = movieName;
+    }
+
+    public Integer getReleaseYear() {
+        return releaseYear;
+    }
+
+    public void setReleaseYear(Integer releaseYear) {
+        this.releaseYear = releaseYear;
+    }
+
+    public String getLanguage() {
+        return language;
+    }
+
+    public void setLanguage(String language) {
+        this.language = language;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+}

persistence-modules/hibernate5/src/main/resources/META-INF/persistence.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<persistence xmlns="http://java.sun.com/xml/ns/persistence"
+             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
+             version="2.0">
+    <persistence-unit name="com.baeldung.movie_catalog">
+        <description>Hibernate EntityManager Demo</description>
+        <class>com.baeldung.hibernate.pojo.Movie</class> 
+        <exclude-unlisted-classes>true</exclude-unlisted-classes>
+        <properties>
+            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5Dialect"/>
+            <property name="hibernate.hbm2ddl.auto" value="update"/>
+            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
+            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://127.0.0.1:3306/moviecatalog"/>
+            <property name="javax.persistence.jdbc.user" value="root"/>
+            <property name="javax.persistence.jdbc.password" value="root"/>
+        </properties>
+    </persistence-unit>
+</persistence> 

persistence-modules/hibernate5/src/main/resources/init_database.sql

@@ -0,0 +1,10 @@
+CREATE ALIAS UPDATE_EMPLOYEE_DESIGNATION AS $$
+import java.sql.CallableStatement;
+import java.sql.Connection;
+import java.sql.SQLException;
+@CODE
+void updateEmployeeDesignation(final Connection conn, final String employeeNumber, final String title) throws SQLException {
+        CallableStatement updateStatement = conn.prepareCall("update deptemployee set title = '" + title + "' where employeeNumber = '" + employeeNumber + "'");
+        updateStatement.execute();
+}
+$$;

persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/NamedQueryIntegrationTest.java

@@ -0,0 +1,98 @@
+package com.baeldung.hibernate;
+
+import com.baeldung.hibernate.entities.Department;
+import com.baeldung.hibernate.entities.DeptEmployee;
+import org.hibernate.Session;
+import org.hibernate.Transaction;
+import org.hibernate.query.NativeQuery;
+import org.hibernate.query.Query;
+import org.junit.*;
+
+import java.io.IOException;
+
+public class NamedQueryIntegrationTest {
+    private static Session session;
+
+    private Transaction transaction;
+    
+    private Long purchaseDeptId;
+    
+    @BeforeClass
+    public static void setUpClass() throws IOException {
+        session = HibernateUtil.getSessionFactory("hibernate-namedquery.properties").openSession();
+    }
+
+    @Before
+    public void setUp() throws IOException {
+        transaction = session.beginTransaction();
+        session.createNativeQuery("delete from deptemployee").executeUpdate();
+        session.createNativeQuery("delete from department").executeUpdate();
+        Department salesDepartment = new Department("Sales");
+        Department purchaseDepartment = new Department("Purchase");        
+        DeptEmployee employee1 = new DeptEmployee("John Wayne", "001", salesDepartment);
+        DeptEmployee employee2 = new DeptEmployee("Sarah Vinton", "002", salesDepartment);
+        DeptEmployee employee3 = new DeptEmployee("Lisa Carter", "003", salesDepartment);
+        session.persist(salesDepartment);
+        session.persist(purchaseDepartment);
+        purchaseDeptId = purchaseDepartment.getId();
+        session.persist(employee1);
+        session.persist(employee2);
+        session.persist(employee3);
+        transaction.commit();
+        transaction = session.beginTransaction();
+    }
+    
+    @After
+    public void tearDown() {
+        if(transaction.isActive()) {
+            transaction.rollback();
+        }
+    }
+
+    @Test
+    public void whenNamedQueryIsCalledUsingCreateNamedQuery_ThenOk() {
+        Query<DeptEmployee> query = session.createNamedQuery("DeptEmployee_FindByEmployeeNumber", DeptEmployee.class);
+        query.setParameter("employeeNo", "001");
+        DeptEmployee result = query.getSingleResult();
+        Assert.assertNotNull(result);
+        Assert.assertEquals("John Wayne", result.getName());
+    }
+       
+    @Test
+    public void whenNamedNativeQueryIsCalledUsingCreateNamedQuery_ThenOk() {
+        Query<DeptEmployee> query = session.createNamedQuery("DeptEmployee_FindByEmployeeName", DeptEmployee.class);
+        query.setParameter("name", "John Wayne");
+        DeptEmployee result = query.getSingleResult();
+        Assert.assertNotNull(result);
+        Assert.assertEquals("001", result.getEmployeeNumber());
+    }
+    
+    @Test
+    public void whenNamedNativeQueryIsCalledUsingGetNamedNativeQuery_ThenOk() {
+        @SuppressWarnings("rawtypes")
+        NativeQuery query = session.getNamedNativeQuery("DeptEmployee_FindByEmployeeName");
+        query.setParameter("name", "John Wayne");
+        DeptEmployee result = (DeptEmployee) query.getSingleResult();
+        Assert.assertNotNull(result);
+        Assert.assertEquals("001", result.getEmployeeNumber());
+    }
+    
+    @Test
+    public void whenUpdateQueryIsCalledWithCreateNamedQuery_ThenOk() {
+        Query spQuery = session.createNamedQuery("DeptEmployee_UpdateEmployeeDepartment");
+        spQuery.setParameter("employeeNo", "001");
+        Department newDepartment = session.find(Department.class, purchaseDeptId);
+        spQuery.setParameter("newDepartment", newDepartment);
+        spQuery.executeUpdate();
+        transaction.commit();        
+    } 
+    
+    @Test
+    public void whenNamedStoredProcedureIsCalledWithCreateNamedQuery_ThenOk() {
+        Query spQuery = session.createNamedQuery("DeptEmployee_UpdateEmployeeDesignation");
+        spQuery.setParameter("employeeNumber", "002");
+        spQuery.setParameter("newDesignation", "Supervisor");
+        spQuery.executeUpdate();
+        transaction.commit();        
+    }       
+}

persistence-modules/hibernate5/src/test/java/com/baeldung/hibernate/persistjson/PersistJSONUnitTest.java

@@ -0,0 +1,111 @@
+package com.baeldung.hibernate.persistjson;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+
+import org.hibernate.HibernateException;
+import org.hibernate.Session;
+import org.hibernate.SessionFactory;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
+import org.hibernate.cfg.Configuration;
+import org.hibernate.service.ServiceRegistry;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+public class PersistJSONUnitTest {
+
+    private Session session;
+
+    @Before
+    public void init() {
+        try {
+            Configuration configuration = new Configuration();
+
+            Properties properties = new Properties();
+            properties.load(Thread.currentThread()
+                .getContextClassLoader()
+                .getResourceAsStream("hibernate-persistjson.properties"));
+
+            configuration.setProperties(properties);
+
+            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties())
+                .build();
+            MetadataSources metadataSources = new MetadataSources(serviceRegistry);
+            metadataSources.addAnnotatedClass(Customer.class);
+
+            SessionFactory factory = metadataSources.buildMetadata()
+                .buildSessionFactory();
+
+            session = factory.openSession();
+        } catch (HibernateException | IOException e) {
+            fail("Failed to initiate Hibernate Session [Exception:" + e.toString() + "]");
+        }
+    }
+
+    @After
+    public void close() {
+        if (session != null)
+            session.close();
+    }
+
+    @Test
+    public void givenCustomer_whenCallingSerializeCustomerAttributes_thenAttributesAreConverted() throws IOException {
+
+        Customer customer = new Customer();
+        customer.setFirstName("first name");
+        customer.setLastName("last name");
+
+        Map<String, Object> attributes = new HashMap<>();
+        attributes.put("address", "123 Main Street");
+        attributes.put("zipcode", 12345);
+
+        customer.setCustomerAttributes(attributes);
+
+        customer.serializeCustomerAttributes();
+
+        String serialized = customer.getCustomerAttributeJSON();
+
+        customer.setCustomerAttributeJSON(serialized);
+        customer.deserializeCustomerAttributes();
+
+        Map<String, Object> deserialized = customer.getCustomerAttributes();
+
+        assertEquals("123 Main Street", deserialized.get("address"));
+    }
+
+    @Test
+    public void givenCustomer_whenSaving_thenAttributesAreConverted() {
+
+        Customer customer = new Customer();
+        customer.setFirstName("first name");
+        customer.setLastName("last name");
+
+        Map<String, Object> attributes = new HashMap<>();
+        attributes.put("address", "123 Main Street");
+        attributes.put("zipcode", 12345);
+
+        customer.setCustomerAttributes(attributes);
+
+        session.beginTransaction();
+
+        int id = (int) session.save(customer);
+
+        session.flush();
+        session.clear();
+
+        Customer result = session.createNativeQuery("select * from Customers where Customers.id = :id", Customer.class)
+            .setParameter("id", id)
+            .getSingleResult();
+
+        assertEquals(2, result.getCustomerAttributes()
+            .size());
+    }
+
+}

persistence-modules/hibernate5/src/test/resources/hibernate-namedquery.properties

@@ -0,0 +1,9 @@
+hibernate.connection.driver_class=org.h2.Driver
+hibernate.connection.url=jdbc:h2:mem:mydb1;DB_CLOSE_DELAY=-1;INIT=RUNSCRIPT FROM 'src/main/resources/init_database.sql'
+hibernate.connection.username=sa
+hibernate.connection.autocommit=true
+jdbc.password=
+
+hibernate.dialect=org.hibernate.dialect.H2Dialect
+hibernate.show_sql=true
+hibernate.hbm2ddl.auto=create-drop

persistence-modules/hibernate5/src/test/resources/hibernate-persistjson.properties

@@ -0,0 +1,7 @@
+hibernate.connection.driver_class=org.h2.Driver
+hibernate.connection.url=jdbc:h2:mem:mydb1;DB_CLOSE_DELAY=-1
+hibernate.connection.username=sa
+hibernate.dialect=org.hibernate.dialect.H2Dialect
+
+hibernate.show_sql=true
+hibernate.hbm2ddl.auto=create-drop