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

cas/cas-secured-app/README.md

@@ -0,0 +1,2 @@
+## Relevant articles:
+- [CAS SSO With Spring Security](http://www.baeldung.com/spring-security-cas-sso)

cas/cas-secured-app/pom.xml

@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.0.0.BUILD-SNAPSHOT</version>
+		<version>2.0.0.M7</version>
 		<relativePath/> <!-- lookup parent from repository -->
 	</parent>
 
@@ -87,14 +87,6 @@
 	</build>
 
 	<repositories>
-		<repository>
-			<id>spring-snapshots</id>
-			<name>Spring Snapshots</name>
-			<url>https://repo.spring.io/snapshot</url>
-			<snapshots>
-				<enabled>true</enabled>
-			</snapshots>
-		</repository>
 		<repository>
 			<id>spring-milestones</id>
 			<name>Spring Milestones</name>
@@ -106,14 +98,6 @@
 	</repositories>
 
 	<pluginRepositories>
-		<pluginRepository>
-			<id>spring-snapshots</id>
-			<name>Spring Snapshots</name>
-			<url>https://repo.spring.io/snapshot</url>
-			<snapshots>
-				<enabled>true</enabled>
-			</snapshots>
-		</pluginRepository>
 		<pluginRepository>
 			<id>spring-milestones</id>
 			<name>Spring Milestones</name>

core-java-8/README.md

@@ -32,3 +32,4 @@
 - [“Stream has already been operated upon or closed” Exception in Java](http://www.baeldung.com/java-stream-operated-upon-or-closed-exception)
 - [Display All Time Zones With GMT And UTC in Java](http://www.baeldung.com/java-time-zones)
 - [Copy a File with Java](http://www.baeldung.com/java-copy-file)
+- [Generating Prime Numbers in Java](http://www.baeldung.com/java-generate-prime-numbers)

core-java-9/README.md

@@ -18,3 +18,4 @@
 - [How to Get All Dates Between Two Dates?](http://www.baeldung.com/java-between-dates)
 - [Java 9 java.util.Objects Additions](http://www.baeldung.com/java-9-objects-new)
 - [Compact Strings in Java 9](http://www.baeldung.com/java-9-compact-string)
+- [Convert Date to LocalDate or LocalDateTime and Back](http://www.baeldung.com/java-date-to-localdate-and-localdatetime)

core-java-concurrency/README.md

@@ -31,3 +31,5 @@
 - [Overview of the java.util.concurrent](http://www.baeldung.com/java-util-concurrent)
 - [Semaphores in Java](http://www.baeldung.com/java-semaphore)
 - [Daemon Threads in Java](http://www.baeldung.com/java-daemon-thread)
+- [Implementing a Runnable vs Extending a Thread](http://www.baeldung.com/java-runnable-vs-extending-thread)
+- [How to Kill a Java Thread](http://www.baeldung.com/java-thread-stop)

core-java/README.md

@@ -121,4 +121,8 @@
 - [Copy a File with Java](http://www.baeldung.com/java-copy-file)
 - [Introduction to Creational Design Patterns](http://www.baeldung.com/creational-design-patterns)
 - [Quick Example - Comparator vs Comparable in Java](http://www.baeldung.com/java-comparator-comparable)
-
+- [Quick Guide to Java Stack](http://www.baeldung.com/java-stack)
+- [The Java continue and break Keywords](http://www.baeldung.com/java-continue-and-break)
+- [Java – Append Data to a File](http://www.baeldung.com/java-append-to-file)
+- [Introduction to the Java ArrayDeque](http://www.baeldung.com/java-array-deque)
+- [Guide to java.util.Formatter](http://www.baeldung.com/java-string-formatter)

core-java/src/main/java/com/baeldung/array/ArrayBenchmarkRunner.java

@@ -0,0 +1,21 @@
+package com.baeldung.array;
+
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+public class ArrayBenchmarkRunner {
+
+  public static void main(String[] args) throws Exception {
+
+    Options options = new OptionsBuilder()
+        .include(SearchArrayTest.class.getSimpleName()).threads(1)
+        .forks(1).shouldFailOnError(true).shouldDoGC(true)
+        .jvmArgs("-server").build();
+
+    new Runner(options).run();
+
+
+  }
+
+}

core-java/src/main/java/com/baeldung/array/ArrayInverter.java

@@ -0,0 +1,41 @@
+package com.baeldung.array;
+
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+import java.util.stream.IntStream;
+
+import org.apache.commons.lang3.ArrayUtils;
+
+import com.google.common.collect.Lists;
+
+public class ArrayInverter {
+
+    public void invertUsingFor(Object[] array) {
+        for (int i = 0; i < array.length / 2; i++) {
+            Object temp = array[i];
+            array[i] = array[array.length - 1 - i];
+            array[array.length - 1 - i] = temp;
+        }
+    }
+
+    public void invertUsingCollectionsReverse(Object[] array) {
+        List<Object> list = Arrays.asList(array);
+        Collections.reverse(list);
+    }
+
+    public Object[] invertUsingStreams(final Object[] array) {
+        return IntStream.range(1, array.length + 1).mapToObj(i -> array[array.length - i]).toArray();
+    }
+
+    public void invertUsingCommonsLang(Object[] array) {
+        ArrayUtils.reverse(array);
+    }
+
+    public Object[] invertUsingGuava(Object[] array) {
+        List<Object> list = Arrays.asList(array);
+        List<Object> reverted = Lists.reverse(list);
+        return reverted.toArray();
+    }
+
+}

core-java/src/main/java/com/baeldung/array/SearchArrayTest.java

@@ -1,78 +1,77 @@
 package com.baeldung.array;
 
-import org.junit.Test;
+import org.openjdk.jmh.annotations.*;
 
 import java.util.*;
+import java.util.concurrent.TimeUnit;
 
+@BenchmarkMode(Mode.AverageTime)
+@Warmup(iterations = 5)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
 public class SearchArrayTest {
 
-
-    @Test
-    public void searchArrayAllocNewCollections() {
+    @Benchmark
+    public void searchArrayLoop() {
 
         int count = 1000;
-
         String[] strings = seedArray(count);
+        for (int i = 0; i < count; i++) {
+            searchLoop(strings, "T");
+        }
+    }
 
-        long startTime = System.nanoTime();
+    @Benchmark
+    public void searchArrayAllocNewList() {
+
+        int count = 1000;
+        String[] strings = seedArray(count);
         for (int i = 0; i < count; i++) {
             searchList(strings, "W");
         }
-        long duration = System.nanoTime() - startTime;
-        System.out.println("SearchList:  " + duration / 10000);
 
-        startTime = System.nanoTime();
-        for (int i = 0; i < count; i++) {
-            searchSet(strings,"S");
-        }
-        duration = System.nanoTime() - startTime;
-        System.out.println("SearchSet:  " + duration / 10000);
-
-        startTime = System.nanoTime();
-        for (int i = 0; i < count; i++) {
-            searchLoop(strings, "T");
-        }
-        duration = System.nanoTime() - startTime;
-        System.out.println("SearchLoop:  " + duration / 10000);
     }
 
-    @Test
-    public void searchArrayReuseCollections() {
+    @Benchmark
+    public void searchArrayAllocNewSet() {
 
-        int count = 10000;
+        int count = 1000;
+        String[] strings = seedArray(count);
+        for (int i = 0; i < count; i++) {
+            searchSet(strings, "S");
+        }
+    }
+
+
+    @Benchmark
+    public void searchArrayReuseList() {
+
+        int count = 1000;
         String[] strings = seedArray(count);
 
         List<String> asList = Arrays.asList(strings);
-        Set<String> asSet = new HashSet<>(Arrays.asList(strings));
 
-        long startTime = System.nanoTime();
         for (int i = 0; i < count; i++) {
             asList.contains("W");
         }
-        long duration = System.nanoTime() - startTime;
-        System.out.println("List:  " + duration / 10000);
-
-        startTime = System.nanoTime();
-        for (int i = 0; i < count; i++) {
-            asSet.contains("S");
-        }
-        duration = System.nanoTime() - startTime;
-        System.out.println("Set:  " + duration / 10000);
-
-        startTime = System.nanoTime();
-        for (int i = 0; i < count; i++) {
-            searchLoop(strings, "T");
-        }
-        duration = System.nanoTime() - startTime;
-        System.out.println("Loop:  " + duration / 10000);
-
     }
 
 
-    @Test
+    @Benchmark
+    public void searchArrayReuseSet() {
+
+        int count = 1000;
+        String[] strings = seedArray(count);
+        Set<String> asSet = new HashSet<>(Arrays.asList(strings));
+        for (int i = 0; i < count; i++) {
+            asSet.contains("S");
+        }
+    }
+
+
+    @Benchmark
     public void searchArrayBinarySearch() {
 
-        int count = 10000;
+        int count = 1000;
         String[] strings = seedArray(count);
         Arrays.sort(strings);
 
@@ -81,7 +80,7 @@ public class SearchArrayTest {
             Arrays.binarySearch(strings, "A");
         }
         long duration = System.nanoTime() - startTime;
-        System.out.println("Binary search:  " + duration / 10000);
+        //System.out.println("Binary search:  " + duration / 10000);
 
     }
 

core-java/src/main/java/com/baeldung/interfaces/CommaSeparatedCustomers.java

@@ -0,0 +1,21 @@
+package com.baeldung.interfaces;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public class CommaSeparatedCustomers implements Customer.List {
+
+    private List<Customer> customers = new ArrayList<Customer>();
+
+    @Override
+    public void Add(Customer customer) {
+        customers.add(customer);
+    }
+
+    @Override
+    public String getCustomerNames() {
+        return customers.stream().map(customer -> customer.getName()).collect(Collectors.joining(","));
+    }
+
+}

core-java/src/main/java/com/baeldung/interfaces/Customer.java

@@ -0,0 +1,19 @@
+package com.baeldung.interfaces;
+
+public class Customer {
+    public interface List {
+        void Add(Customer customer);
+
+        String getCustomerNames();
+    }
+
+    private String name;
+
+    public Customer(String name) {
+        this.name = name;
+    }
+
+    String getName() {
+        return name;
+    }
+}

core-java/src/main/java/com/baeldung/polymorphism/GenericFile.java

@@ -54,7 +54,7 @@ public class GenericFile {
     }
 
     public String getFileInfo() {
-        return "File Name: " + this.getName() + "\n" + "Extension: " + this.getExtension() + "\n" + "Date Created: " + this.getDateCreated() + "\n" + "Version: " + this.getVersion() + "\n";
+        return String.format("File Name: %s\n" + " Extension: %s\n" + " Date Created: %s\n" + " Version: %s\n", this.getName(), this.getExtension(), this.getDateCreated(), this.getVersion());
     }
 
     public Object read() {

core-java/src/main/java/com/baeldung/polymorphism/ImageFile.java

@@ -30,7 +30,7 @@ public class ImageFile extends GenericFile {
     }
 
     public String getFileInfo() {
-        return super.getFileInfo() + "Height: " + this.getHeight() + "\n" + "Width: " + this.getWidth();
+        return String.format(" %s Height: %d\n Width: %d", super.getFileInfo(), this.getHeight(), this.getWidth());
     }
 
     public String read() {

core-java/src/main/java/com/baeldung/polymorphism/TextFile.java

@@ -21,7 +21,7 @@ public class TextFile extends GenericFile {
     }
 
     public String getFileInfo() {
-        return super.getFileInfo() + "Word Count: " + wordCount;
+        return String.format(" %s Word Count: %d", super.getFileInfo(), wordCount);
     }
 
     public String read() {

core-java/src/main/java/com/baeldung/tree/BinaryTree.java

@@ -0,0 +1,216 @@
+package com.baeldung.tree;
+
+import java.util.LinkedList;
+import java.util.Queue;
+
+public class BinaryTree {
+
+    Node root;
+
+    public void add(int value) {
+
+        Node newNode = new Node(value);
+
+        if (root == null) {
+            root = newNode;
+            return;
+        }
+
+        Node parent = root;
+        Node current = root;
+
+        while (true) {
+
+            if (newNode.value < parent.value) {
+                current = parent.left;
+
+                if (current == null) {
+                    parent.left = newNode;
+                    break;
+                }
+            } else {
+                current = parent.right;
+
+                if (current == null) {
+                    parent.right = newNode;
+                    break;
+                }
+            }
+
+            parent = current;
+        }
+    }
+
+    public boolean isEmpty() {
+        return root == null;
+    }
+
+    public boolean containsNode(int value) {
+
+        Node current = root;
+
+        while (current != null) {
+
+            if (value == current.value) {
+                return true;
+            }
+
+            if (value < current.value) {
+                current = current.left;
+            } else {
+                current = current.right;
+            }
+
+        }
+
+        return false;
+    }
+
+    public void delete(int value) {
+
+        Node current = root;
+        Node parent = root;
+        Node nodeToDelete = null;
+        boolean isLeftChild = false;
+
+        while (nodeToDelete == null && current != null) {
+
+            if (value == current.value) {
+                nodeToDelete = current;
+            } else if (value < current.value) {
+                parent = current;
+                current = current.left;
+                isLeftChild = true;
+            } else {
+                parent = current;
+                current = current.right;
+                isLeftChild = false;
+            }
+
+        }
+
+        if (nodeToDelete == null) {
+            return;
+        }
+
+        // Case 1: no children
+        if (nodeToDelete.left == null && nodeToDelete.right == null) {
+            if (nodeToDelete == root) {
+                root = null;
+            } else if (isLeftChild) {
+                parent.left = null;
+            } else {
+                parent.right = null;
+            }
+        }
+        // Case 2: only 1 child
+        else if (nodeToDelete.right == null) {
+            if (nodeToDelete == root) {
+                root = nodeToDelete.left;
+            } else if (isLeftChild) {
+                parent.left = nodeToDelete.left;
+            } else {
+                parent.right = nodeToDelete.left;
+            }
+        } else if (nodeToDelete.left == null) {
+            if (nodeToDelete == root) {
+                root = nodeToDelete.right;
+            } else if (isLeftChild) {
+                parent.left = nodeToDelete.right;
+            } else {
+                parent.right = nodeToDelete.right;
+            }
+        }
+        // Case 3: 2 children
+        else if (nodeToDelete.left != null && nodeToDelete.right != null) {
+            Node replacement = findReplacement(nodeToDelete);
+            if (nodeToDelete == root) {
+                root = replacement;
+            } else if (isLeftChild) {
+                parent.left = replacement;
+            } else {
+                parent.right = replacement;
+            }
+        }
+
+    }
+
+    private Node findReplacement(Node nodeToDelete) {
+
+        Node replacement = nodeToDelete;
+        Node parentReplacement = nodeToDelete;
+        Node current = nodeToDelete.right;
+
+        while (current != null) {
+            parentReplacement = replacement;
+            replacement = current;
+            current = current.left;
+        }
+
+        if (replacement != nodeToDelete.right) {
+            parentReplacement.left = replacement.right;
+            replacement.right = nodeToDelete.right;
+        }
+
+        replacement.left = nodeToDelete.left;
+
+        return replacement;
+    }
+
+    public void traverseInOrder(Node node) {
+        if (node != null) {
+            traverseInOrder(node.left);
+            System.out.print(" " + node.value);
+            traverseInOrder(node.right);
+        }
+    }
+
+    public void traversePreOrder(Node node) {
+        if (node != null) {
+            System.out.print(" " + node.value);
+            traversePreOrder(node.left);
+            traversePreOrder(node.right);
+        }
+    }
+
+    public void traversePostOrder(Node node) {
+        if (node != null) {
+            traversePostOrder(node.left);
+            traversePostOrder(node.right);
+
+            System.out.print(" " + node.value);
+        }
+    }
+
+    public void traverseLevelOrder() {
+        Queue<Node> nodes = new LinkedList<>();
+        nodes.add(root);
+
+        while (!nodes.isEmpty()) {
+
+            Node node = nodes.remove();
+
+            System.out.print(" " + node.value);
+
+            if (node.left != null) {
+                nodes.add(node.left);
+            }
+
+            if (node.left != null) {
+                nodes.add(node.right);
+            }
+        }
+    }
+
+    class Node {
+        int value;
+        Node left;
+        Node right;
+
+        Node(int value) {
+            this.value = value;
+            right = null;
+            left = null;
+        }
+    }
+}

core-java/src/main/resources/countries.properties

@@ -1,3 +1,3 @@
-UK
-US
-Germany
+UK
+US
+Germany

core-java/src/test/java/com/baeldung/array/ArrayInverterUnitTest.java

@@ -0,0 +1,49 @@
+package com.baeldung.array;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+
+public class ArrayInverterUnitTest {
+
+    private String[] fruits = { "apples", "tomatoes", "bananas", "guavas", "pineapples", "oranges" };
+
+    @Test
+    public void invertArrayWithForLoop() {
+        ArrayInverter inverter = new ArrayInverter();
+        inverter.invertUsingFor(fruits);
+
+        assertThat(new String[] { "oranges", "pineapples", "guavas", "bananas", "tomatoes", "apples" }).isEqualTo(fruits);
+    }
+
+    @Test
+    public void invertArrayWithCollectionsReverse() {
+        ArrayInverter inverter = new ArrayInverter();
+        inverter.invertUsingCollectionsReverse(fruits);
+
+        assertThat(new String[] { "oranges", "pineapples", "guavas", "bananas", "tomatoes", "apples" }).isEqualTo(fruits);
+    }
+
+    @Test
+    public void invertArrayWithStreams() {
+        ArrayInverter inverter = new ArrayInverter();
+
+        assertThat(new String[] { "oranges", "pineapples", "guavas", "bananas", "tomatoes", "apples" }).isEqualTo(inverter.invertUsingStreams(fruits));
+    }
+
+    @Test
+    public void invertArrayWithCommonsLang() {
+        ArrayInverter inverter = new ArrayInverter();
+        inverter.invertUsingCommonsLang(fruits);
+
+        assertThat(new String[] { "oranges", "pineapples", "guavas", "bananas", "tomatoes", "apples" }).isEqualTo(fruits);
+    }
+
+    @Test
+    public void invertArrayWithGuava() {
+        ArrayInverter inverter = new ArrayInverter();
+
+        assertThat(new String[] { "oranges", "pineapples", "guavas", "bananas", "tomatoes", "apples" }).isEqualTo(inverter.invertUsingGuava(fruits));
+    }
+
+}

core-java/src/test/java/com/baeldung/file/FilesTest.java

@@ -91,4 +91,4 @@ public class FilesTest {
             new FileInputStream(fileName)))
           .isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\n");
     }
-}
+}

core-java/src/test/java/com/baeldung/interfaces/InnerInterfaceTests.java

@@ -0,0 +1,18 @@
+package com.baeldung.interfaces;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class InnerInterfaceTests {
+    @Test
+    public void whenCustomerListJoined_thenReturnsJoinedNames() {
+        Customer.List customerList = new CommaSeparatedCustomers();
+        customerList.Add(new Customer("customer1"));
+        customerList.Add(new Customer("customer2"));
+        assertEquals("customer1,customer2", customerList.getCustomerNames());
+    }
+}

core-java/src/test/java/com/baeldung/nestedclass/NewOuter.java

@@ -14,9 +14,9 @@ public class NewOuter {
         public void run() {
             System.out.println("a = " + a);
             System.out.println("b = " + b);
-            System.out.println("NewOuterTest.this.a = " + NewOuter.this.a);
-            System.out.println("NewOuterTest.b = " + NewOuter.b);
-            System.out.println("NewOuterTest.this.b = " + NewOuter.this.b);
+            System.out.println("NewOuter.this.a = " + NewOuter.this.a);
+            System.out.println("NewOuter.b = " + NewOuter.b);
+            System.out.println("NewOuter.this.b = " + NewOuter.this.b);
         }
     }
 

core-java/src/test/java/com/baeldung/polymorphism/PolymorphismUnitTest.java

@@ -3,8 +3,6 @@ package com.baeldung.polymorphism;
 import static org.junit.Assert.*;
 
 import java.awt.image.BufferedImage;
-
-import org.junit.Ignore;
 import org.junit.Test;
 
 public class PolymorphismUnitTest {

core-java/src/test/java/com/baeldung/tree/BinaryTreeTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.tree;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class BinaryTreeTest {
+
+    @Test
+    public void givenABinaryTree_WhenAddingElements_ThenTreeNotEmpty() {
+
+        BinaryTree bt = createBinaryTree();
+
+        assertTrue(!bt.isEmpty());
+    }
+
+    @Test
+    public void givenABinaryTree_WhenAddingElements_ThenTreeContainsThoseElements() {
+
+        BinaryTree bt = createBinaryTree();
+
+        assertTrue(bt.containsNode(6));
+        assertTrue(bt.containsNode(4));
+
+        assertFalse(bt.containsNode(1));
+    }
+
+    @Test
+    public void givenABinaryTree_WhenDeletingElements_ThenTreeDoesNotContainThoseElements() {
+
+        BinaryTree bt = createBinaryTree();
+
+        assertTrue(bt.containsNode(9));
+        bt.delete(9);
+        assertFalse(bt.containsNode(9));
+    }
+
+    @Test
+    public void givenABinaryTree_WhenTraversingInOrder_ThenPrintValues() {
+
+        BinaryTree bt = createBinaryTree();
+
+        bt.traverseInOrder(bt.root);
+    }
+
+    @Test
+    public void givenABinaryTree_WhenTraversingPreOrder_ThenPrintValues() {
+
+        BinaryTree bt = createBinaryTree();
+
+        bt.traversePreOrder(bt.root);
+    }
+
+    @Test
+    public void givenABinaryTree_WhenTraversingPostOrder_ThenPrintValues() {
+
+        BinaryTree bt = createBinaryTree();
+
+        bt.traversePostOrder(bt.root);
+    }
+
+    @Test
+    public void givenABinaryTree_WhenTraversingLevelOrder_ThenPrintValues() {
+
+        BinaryTree bt = createBinaryTree();
+
+        bt.traverseLevelOrder();
+    }
+
+    private BinaryTree createBinaryTree() {
+        BinaryTree bt = new BinaryTree();
+
+        bt.add(6);
+        bt.add(4);
+        bt.add(8);
+        bt.add(3);
+        bt.add(5);
+        bt.add(7);
+        bt.add(9);
+
+        return bt;
+    }
+
+}

drools/README.MD

@@ -1,3 +1,4 @@
 ### Relevant Articles:
 - [Introduction to Drools](http://www.baeldung.com/drools)
 - [Drools Using Rules from Excel Files](http://www.baeldung.com/drools-excel)
+- [An Example of Backward Chaining in Drools](http://www.baeldung.com/drools-backward-chaining)

dubbo/README.md

@@ -0,0 +1,4 @@
+## Relevant articles:
+
+- [Intro to Dubbo](http://www.baeldung.com/dubbo-intro)
+

dubbo/pom.xml

@@ -0,0 +1,72 @@
+<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>
+
+    <parent>
+        <artifactId>parent-modules</artifactId>
+        <groupId>com.baeldung</groupId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <artifactId>dubbo</artifactId>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <java.version>1.8</java.version>
+        <dubbo.version>2.5.7</dubbo.version>
+        <zookeeper.version>3.4.11</zookeeper.version>
+        <zkclient.version>0.10</zkclient.version>
+        <surefire.version>2.19.1</surefire.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.alibaba</groupId>
+            <artifactId>dubbo</artifactId>
+            <version>${dubbo.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.12</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.apache.zookeeper</groupId>
+            <artifactId>zookeeper</artifactId>
+            <version>${zookeeper.version}</version>
+        </dependency>
+
+        <dependency>
+            <groupId>com.101tec</groupId>
+            <artifactId>zkclient</artifactId>
+            <version>${zkclient.version}</version>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>${surefire.version}</version>
+                <configuration>
+                    <excludes>
+                        <exclude>**/*LiveTest.java</exclude>
+                    </excludes>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

dubbo/src/main/java/com/alibaba/dubbo/registry/simple/SimpleRegistryService.java

@@ -0,0 +1,210 @@
+/*
+ * Copyright 1999-2011 Alibaba Group.
+ *  
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *  
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *  
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.alibaba.dubbo.registry.simple;
+
+import com.alibaba.dubbo.common.Constants;
+import com.alibaba.dubbo.common.URL;
+import com.alibaba.dubbo.common.logger.Logger;
+import com.alibaba.dubbo.common.logger.LoggerFactory;
+import com.alibaba.dubbo.common.utils.ConcurrentHashSet;
+import com.alibaba.dubbo.common.utils.NetUtils;
+import com.alibaba.dubbo.common.utils.UrlUtils;
+import com.alibaba.dubbo.registry.NotifyListener;
+import com.alibaba.dubbo.registry.RegistryService;
+import com.alibaba.dubbo.registry.support.AbstractRegistry;
+import com.alibaba.dubbo.rpc.RpcContext;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
+
+/**
+ * SimpleRegistryService
+ *
+ * @author william.liangf
+ */
+public class SimpleRegistryService extends AbstractRegistry {
+
+    private final static Logger logger = LoggerFactory.getLogger(SimpleRegistryService.class);
+    private final ConcurrentMap<String, Set<URL>> remoteRegistered = new ConcurrentHashMap<String, Set<URL>>();
+    private final ConcurrentMap<String, ConcurrentMap<URL, Set<NotifyListener>>> remoteSubscribed = new ConcurrentHashMap<String, ConcurrentMap<URL, Set<NotifyListener>>>();
+
+    public SimpleRegistryService() {
+        super(new URL("dubbo", NetUtils.getLocalHost(), 0, RegistryService.class.getName(), "file", "N/A"));
+    }
+
+    public boolean isAvailable() {
+        return true;
+    }
+
+    public List<URL> lookup(URL url) {
+        List<URL> urls = new ArrayList<URL>();
+        for (URL u : getRegistered()) {
+            if (UrlUtils.isMatch(url, u)) {
+                urls.add(u);
+            }
+        }
+        return urls;
+    }
+
+    public void register(URL url) {
+        String client = RpcContext.getContext().getRemoteAddressString();
+        Set<URL> urls = remoteRegistered.get(client);
+        if (urls == null) {
+            remoteRegistered.putIfAbsent(client, new ConcurrentHashSet<URL>());
+            urls = remoteRegistered.get(client);
+        }
+        urls.add(url);
+        super.register(url);
+        registered(url);
+    }
+
+    public void unregister(URL url) {
+        String client = RpcContext.getContext().getRemoteAddressString();
+        Set<URL> urls = remoteRegistered.get(client);
+        if (urls != null && urls.size() > 0) {
+            urls.remove(url);
+        }
+        super.unregister(url);
+        unregistered(url);
+    }
+
+    public void subscribe(URL url, NotifyListener listener) {
+        if (getUrl().getPort() == 0) {
+            URL registryUrl = RpcContext.getContext().getUrl();
+            if (registryUrl != null && registryUrl.getPort() > 0
+                    && RegistryService.class.getName().equals(registryUrl.getPath())) {
+                super.setUrl(registryUrl);
+                super.register(registryUrl);
+            }
+        }
+        String client = RpcContext.getContext().getRemoteAddressString();
+        ConcurrentMap<URL, Set<NotifyListener>> clientListeners = remoteSubscribed.get(client);
+        if (clientListeners == null) {
+            remoteSubscribed.putIfAbsent(client, new ConcurrentHashMap<URL, Set<NotifyListener>>());
+            clientListeners = remoteSubscribed.get(client);
+        }
+        Set<NotifyListener> listeners = clientListeners.get(url);
+        if (listeners == null) {
+            clientListeners.putIfAbsent(url, new ConcurrentHashSet<NotifyListener>());
+            listeners = clientListeners.get(url);
+        }
+        listeners.add(listener);
+        super.subscribe(url, listener);
+        subscribed(url, listener);
+    }
+
+    public void unsubscribe(URL url, NotifyListener listener) {
+        if (!Constants.ANY_VALUE.equals(url.getServiceInterface())
+                && url.getParameter(Constants.REGISTER_KEY, true)) {
+            unregister(url);
+        }
+        String client = RpcContext.getContext().getRemoteAddressString();
+        Map<URL, Set<NotifyListener>> clientListeners = remoteSubscribed.get(client);
+        if (clientListeners != null && clientListeners.size() > 0) {
+            Set<NotifyListener> listeners = clientListeners.get(url);
+            if (listeners != null && listeners.size() > 0) {
+                listeners.remove(listener);
+            }
+        }
+    }
+
+    protected void registered(URL url) {
+        for (Map.Entry<URL, Set<NotifyListener>> entry : getSubscribed().entrySet()) {
+            URL key = entry.getKey();
+            if (UrlUtils.isMatch(key, url)) {
+                List<URL> list = lookup(key);
+                for (NotifyListener listener : entry.getValue()) {
+                    listener.notify(list);
+                }
+            }
+        }
+    }
+
+    protected void unregistered(URL url) {
+        for (Map.Entry<URL, Set<NotifyListener>> entry : getSubscribed().entrySet()) {
+            URL key = entry.getKey();
+            if (UrlUtils.isMatch(key, url)) {
+                List<URL> list = lookup(key);
+                for (NotifyListener listener : entry.getValue()) {
+                    listener.notify(list);
+                }
+            }
+        }
+    }
+
+    protected void subscribed(final URL url, final NotifyListener listener) {
+        if (Constants.ANY_VALUE.equals(url.getServiceInterface())) {
+            new Thread(new Runnable() {
+                public void run() {
+                    Map<String, List<URL>> map = new HashMap<String, List<URL>>();
+                    for (URL u : getRegistered()) {
+                        if (UrlUtils.isMatch(url, u)) {
+                            String service = u.getServiceInterface();
+                            List<URL> list = map.get(service);
+                            if (list == null) {
+                                list = new ArrayList<URL>();
+                                map.put(service, list);
+                            }
+                            list.add(u);
+                        }
+                    }
+                    for (List<URL> list : map.values()) {
+                        try {
+                            listener.notify(list);
+                        } catch (Throwable e) {
+                            logger.warn("Discard to notify " + url.getServiceKey() + " to listener " + listener);
+                        }
+                    }
+                }
+            }, "DubboMonitorNotifier").start();
+        } else {
+            List<URL> list = lookup(url);
+            try {
+                listener.notify(list);
+            } catch (Throwable e) {
+                logger.warn("Discard to notify " + url.getServiceKey() + " to listener " + listener);
+            }
+        }
+    }
+
+    public void disconnect() {
+        String client = RpcContext.getContext().getRemoteAddressString();
+        if (logger.isInfoEnabled()) {
+            logger.info("Disconnected " + client);
+        }
+        Set<URL> urls = remoteRegistered.get(client);
+        if (urls != null && urls.size() > 0) {
+            for (URL url : urls) {
+                unregister(url);
+            }
+        }
+        Map<URL, Set<NotifyListener>> listeners = remoteSubscribed.get(client);
+        if (listeners != null && listeners.size() > 0) {
+            for (Map.Entry<URL, Set<NotifyListener>> entry : listeners.entrySet()) {
+                URL url = entry.getKey();
+                for (NotifyListener listener : entry.getValue()) {
+                    unsubscribe(url, listener);
+                }
+            }
+        }
+    }
+
+}

dubbo/src/main/java/com/baeldung/dubbo/remote/GreetingsFailoverServiceImpl.java

@@ -0,0 +1,14 @@
+package com.baeldung.dubbo.remote;
+
+/**
+ * @author aiet
+ */
+public class GreetingsFailoverServiceImpl implements GreetingsService {
+
+    @Override
+    public String sayHi(String name) {
+        System.out.println("failover implementation");
+        return "hi, failover " + name;
+    }
+
+}

dubbo/src/main/java/com/baeldung/dubbo/remote/GreetingsService.java

@@ -0,0 +1,10 @@
+package com.baeldung.dubbo.remote;
+
+/**
+ * @author aiet
+ */
+public interface GreetingsService {
+
+    String sayHi(String name);
+
+}

dubbo/src/main/java/com/baeldung/dubbo/remote/GreetingsServiceImpl.java

@@ -0,0 +1,14 @@
+package com.baeldung.dubbo.remote;
+
+/**
+ * @author aiet
+ */
+public class GreetingsServiceImpl implements GreetingsService {
+
+    @Override
+    public String sayHi(String name) {
+        System.out.println("default implementation");
+        return "hi, " + name;
+    }
+
+}

dubbo/src/main/java/com/baeldung/dubbo/remote/GreetingsServiceSpecialImpl.java

@@ -0,0 +1,20 @@
+package com.baeldung.dubbo.remote;
+
+import static java.util.concurrent.TimeUnit.SECONDS;
+
+/**
+ * @author aiet
+ */
+public class GreetingsServiceSpecialImpl implements GreetingsService {
+
+    @Override
+    public String sayHi(String name) {
+        try {
+            System.out.println("specially called");
+            SECONDS.sleep(5);
+        } catch (Exception ignored) {
+        }
+        return "hi, " + name;
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/APIConfigurationLiveTest.java

@@ -0,0 +1,57 @@
+package com.baeldung.dubbo;
+
+import com.alibaba.dubbo.config.ApplicationConfig;
+import com.alibaba.dubbo.config.ReferenceConfig;
+import com.alibaba.dubbo.config.RegistryConfig;
+import com.alibaba.dubbo.config.ServiceConfig;
+import com.baeldung.dubbo.remote.GreetingsService;
+import com.baeldung.dubbo.remote.GreetingsServiceImpl;
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author aiet
+ */
+public class APIConfigurationLiveTest {
+
+    @Before
+    public void initProvider() {
+        ApplicationConfig application = new ApplicationConfig();
+        application.setName("demo-provider");
+        application.setVersion("1.0");
+
+        RegistryConfig registryConfig = new RegistryConfig();
+        registryConfig.setAddress("multicast://224.1.1.1:9090");
+
+        ServiceConfig<GreetingsService> service = new ServiceConfig<>();
+        service.setApplication(application);
+        service.setRegistry(registryConfig);
+        service.setInterface(GreetingsService.class);
+        service.setRef(new GreetingsServiceImpl());
+
+        service.export();
+    }
+
+    @Test
+    public void givenProviderConsumer_whenSayHi_thenGotResponse() {
+        ApplicationConfig application = new ApplicationConfig();
+        application.setName("demo-consumer");
+        application.setVersion("1.0");
+
+        RegistryConfig registryConfig = new RegistryConfig();
+        registryConfig.setAddress("multicast://224.1.1.1:9090");
+
+        ReferenceConfig<GreetingsService> reference = new ReferenceConfig<>();
+        reference.setApplication(application);
+        reference.setRegistry(registryConfig);
+        reference.setInterface(GreetingsService.class);
+
+        GreetingsService greetingsService = reference.get();
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        assertEquals("hi, baeldung", hiMessage);
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/ClusterDynamicLoadBalanceLiveTest.java

@@ -0,0 +1,70 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.OptionalDouble;
+import java.util.concurrent.Callable;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static java.util.concurrent.TimeUnit.SECONDS;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author aiet
+ */
+public class ClusterDynamicLoadBalanceLiveTest {
+
+    private ExecutorService executorService;
+
+    @Before
+    public void initRemote() {
+        executorService = Executors.newFixedThreadPool(2);
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext remoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-default.xml");
+            remoteContext.start();
+        });
+        executorService.submit(() -> {
+            SECONDS.sleep(2);
+            ClassPathXmlApplicationContext backupRemoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-special.xml");
+            backupRemoteContext.start();
+            return null;
+        });
+    }
+
+    @Test
+    public void givenProviderCluster_whenConsumerSaysHi_thenResponseBalanced() throws InterruptedException {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("cluster/consumer-app-lb.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        List<Long> elapseList = new ArrayList<>(6);
+        for (int i = 0; i < 6; i++) {
+            long current = System.currentTimeMillis();
+            String hiMessage = greetingsService.sayHi("baeldung");
+            assertNotNull(hiMessage);
+            elapseList.add(System.currentTimeMillis() - current);
+            SECONDS.sleep(1);
+        }
+
+        OptionalDouble avgElapse = elapseList
+          .stream()
+          .mapToLong(e -> e)
+          .average();
+        assertTrue(avgElapse.isPresent());
+        assertTrue(avgElapse.getAsDouble() > 1666.0);
+
+    }
+
+    @After
+    public void destroy() {
+        executorService.shutdown();
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/ClusterFailoverLiveTest.java

@@ -0,0 +1,52 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * @author aiet
+ */
+public class ClusterFailoverLiveTest {
+
+    private ExecutorService executorService;
+
+    @Before
+    public void initRemote() {
+        executorService = Executors.newFixedThreadPool(2);
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext backupRemoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-special.xml");
+            backupRemoteContext.start();
+        });
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext remoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-failover.xml");
+            remoteContext.start();
+        });
+
+    }
+
+    @Test
+    public void givenProviderCluster_whenConsumerSaysHi_thenGotFailoverResponse() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("cluster/consumer-app-failtest.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        assertNotNull(hiMessage);
+        assertEquals("hi, failover baeldung", hiMessage);
+    }
+
+    @After
+    public void destroy() {
+        executorService.shutdown();
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/ClusterFailsafeLiveTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+/**
+ * @author aiet
+ */
+public class ClusterFailsafeLiveTest {
+
+    private ExecutorService executorService;
+
+    @Before
+    public void initRemote() {
+        executorService = Executors.newFixedThreadPool(1);
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext remoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-special-failsafe.xml");
+            remoteContext.start();
+        });
+    }
+
+    @Test
+    public void givenProviderCluster_whenConsumerSaysHi_thenGotFailsafeResponse() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("cluster/consumer-app-failtest.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        assertNull(hiMessage);
+    }
+
+    @After
+    public void destroy() {
+        executorService.shutdown();
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/ClusterLoadBalanceLiveTest.java

@@ -0,0 +1,66 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.OptionalDouble;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author aiet
+ */
+public class ClusterLoadBalanceLiveTest {
+
+    private ExecutorService executorService;
+
+    @Before
+    public void initRemote() {
+        executorService = Executors.newFixedThreadPool(2);
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext remoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-default.xml");
+            remoteContext.start();
+        });
+        executorService.submit(() -> {
+            ClassPathXmlApplicationContext backupRemoteContext = new ClassPathXmlApplicationContext("cluster/provider-app-special.xml");
+            backupRemoteContext.start();
+        });
+    }
+
+    @Test
+    public void givenProviderCluster_whenConsumerSaysHi_thenResponseBalanced() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("cluster/consumer-app-lb.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        List<Long> elapseList = new ArrayList<>(6);
+        for (int i = 0; i < 6; i++) {
+            long current = System.currentTimeMillis();
+            String hiMessage = greetingsService.sayHi("baeldung");
+            assertNotNull(hiMessage);
+            elapseList.add(System.currentTimeMillis() - current);
+        }
+
+        OptionalDouble avgElapse = elapseList
+          .stream()
+          .mapToLong(e -> e)
+          .average();
+        assertTrue(avgElapse.isPresent());
+        System.out.println(avgElapse.getAsDouble());
+        assertTrue(avgElapse.getAsDouble() > 2500.0);
+
+    }
+
+    @After
+    public void destroy() {
+        executorService.shutdown();
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/MulticastRegistryLiveTest.java

@@ -0,0 +1,36 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * @author aiet
+ */
+public class MulticastRegistryLiveTest {
+
+    private ClassPathXmlApplicationContext remoteContext;
+
+    @Before
+    public void initRemote() {
+        remoteContext = new ClassPathXmlApplicationContext("multicast/provider-app.xml");
+        remoteContext.start();
+    }
+
+    @Test
+    public void givenProvider_whenConsumerSaysHi_thenGotResponse() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("multicast/consumer-app.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        assertNotNull(hiMessage);
+        assertEquals("hi, baeldung", hiMessage);
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/ResultCacheLiveTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author aiet
+ */
+public class ResultCacheLiveTest {
+
+    private ClassPathXmlApplicationContext remoteContext;
+
+    @Before
+    public void initRemote() {
+        remoteContext = new ClassPathXmlApplicationContext("multicast/provider-app-special.xml");
+        remoteContext.start();
+    }
+
+    @Test
+    public void givenProvider_whenConsumerSaysHi_thenGotResponse() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("multicast/consumer-app.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+
+        long before = System.currentTimeMillis();
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        long timeElapsed = System.currentTimeMillis() - before;
+        assertTrue(timeElapsed > 5000);
+        assertNotNull(hiMessage);
+        assertEquals("hi, baeldung", hiMessage);
+
+
+        before = System.currentTimeMillis();
+        hiMessage = greetingsService.sayHi("baeldung");
+        timeElapsed = System.currentTimeMillis() - before;
+        assertTrue(timeElapsed < 1000);
+        assertNotNull(hiMessage);
+        assertEquals("hi, baeldung", hiMessage);
+    }
+
+}

dubbo/src/test/java/com/baeldung/dubbo/SimpleRegistryLiveTest.java

@@ -0,0 +1,39 @@
+package com.baeldung.dubbo;
+
+import com.baeldung.dubbo.remote.GreetingsService;
+import org.junit.Before;
+import org.junit.Test;
+import org.springframework.context.support.ClassPathXmlApplicationContext;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * @author aiet
+ */
+public class SimpleRegistryLiveTest {
+
+    private ClassPathXmlApplicationContext remoteContext;
+    private ClassPathXmlApplicationContext registryContext;
+
+    @Before
+    public void initRemote() {
+        registryContext = new ClassPathXmlApplicationContext("simple/registry.xml");
+        registryContext.start();
+
+        remoteContext = new ClassPathXmlApplicationContext("simple/provider-app.xml");
+        remoteContext.start();
+    }
+
+    @Test
+    public void givenProvider_whenConsumerSaysHi_thenGotResponse() {
+        ClassPathXmlApplicationContext localContext = new ClassPathXmlApplicationContext("simple/consumer-app.xml");
+        localContext.start();
+        GreetingsService greetingsService = (GreetingsService) localContext.getBean("greetingsService");
+        String hiMessage = greetingsService.sayHi("baeldung");
+
+        assertNotNull(hiMessage);
+        assertEquals("hi, baeldung", hiMessage);
+    }
+
+}

dubbo/src/test/resources/cluster/consumer-app-failtest.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-consumer" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- remote service proxy, acting like a local bean while invoking -->
+    <dubbo:reference interface="com.baeldung.dubbo.remote.GreetingsService" id="greetingsService" retries="2" timeout="2000" />
+
+</beans>

dubbo/src/test/resources/cluster/consumer-app-lb.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-consumer" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- remote service proxy, acting like a local bean while invoking -->
+    <dubbo:reference interface="com.baeldung.dubbo.remote.GreetingsService" id="greetingsService" retries="2" timeout="10000" loadbalance="roundrobin" />
+
+</beans>

dubbo/src/test/resources/cluster/provider-app-default.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20880"/>
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService" cluster="failsafe"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceImpl"/>
+
+</beans>

dubbo/src/test/resources/cluster/provider-app-failover.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20880"/>
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService" cluster="failover"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsFailoverServiceImpl"/>
+
+</beans>

dubbo/src/test/resources/cluster/provider-app-special-failsafe.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20881" />
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService" cluster="failsafe"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceSpecialImpl"/>
+
+</beans>

dubbo/src/test/resources/cluster/provider-app-special.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20881" />
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService" cluster="failover"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceSpecialImpl"/>
+
+</beans>

dubbo/src/test/resources/log4j.properties

@@ -0,0 +1,6 @@
+log4j.rootLogger=INFO, stdout
+
+log4j.appender.stdout=org.apache.log4j.ConsoleAppender
+log4j.appender.stdout.Target=System.out
+log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
+log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

dubbo/src/test/resources/multicast/consumer-app.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-consumer" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="multicast://224.1.1.1:9090"/>
+
+    <!-- remote service proxy, acting like a local bean while invoking -->
+    <dubbo:reference interface="com.baeldung.dubbo.remote.GreetingsService" id="greetingsService" cache="lru" />
+
+</beans>

dubbo/src/test/resources/multicast/provider-app-special.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="multicast://224.1.1.1:9090"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20881" />
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceSpecialImpl"/>
+
+</beans>

dubbo/src/test/resources/multicast/provider-app.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="multicast://224.1.1.1:9090"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20880"/>
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceImpl"/>
+
+</beans>

dubbo/src/test/resources/simple/consumer-app.xml

@@ -0,0 +1,15 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-consumer" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="127.0.0.1:9090"/>
+
+    <!-- remote service proxy, acting like a local bean while invoking -->
+    <dubbo:reference interface="com.baeldung.dubbo.remote.GreetingsService" id="greetingsService" cluster="failover" retries="2"/>
+
+</beans>

dubbo/src/test/resources/simple/provider-app.xml

@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <!-- provider application meta -->
+    <dubbo:application name="demo-provider" version="1.0"/>
+
+    <!-- address used to expose provider's service  -->
+    <dubbo:registry address="127.0.0.1:9090"/>
+
+    <!-- protocol and port used to expose service -->
+    <dubbo:protocol name="dubbo" port="20880"/>
+
+    <!-- the service interface to expose -->
+    <dubbo:service interface="com.baeldung.dubbo.remote.GreetingsService" ref="greetingsService"/>
+
+    <!-- declare the local implementation of exposed service interface -->
+    <bean id="greetingsService" class="com.baeldung.dubbo.remote.GreetingsServiceImpl"/>
+
+</beans>

dubbo/src/test/resources/simple/registry.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<beans xmlns="http://www.springframework.org/schema/beans"
+       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
+       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
+
+    <dubbo:application name="simple-registry" />
+
+    <dubbo:protocol port="9090" />
+
+    <dubbo:service interface="com.alibaba.dubbo.registry.RegistryService" ref="registryService" registry="N/A" ondisconnect="disconnect">
+        <dubbo:method name="subscribe"><dubbo:argument index="1" callback="true" /></dubbo:method>
+        <dubbo:method name="unsubscribe"><dubbo:argument index="1" callback="true" /></dubbo:method>
+    </dubbo:service>
+
+    <bean id="registryService" class="com.alibaba.dubbo.registry.simple.SimpleRegistryService" />
+
+</beans>

flyway/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>
-    <groupId>com.baeldung</groupId>
     <artifactId>flyway</artifactId>
     <version>1.0</version>
     <name>flyway</name>
+    <packaging>pom</packaging>
     <description>A sample project to demonstrate Flyway migrations</description>
 
     <parent>
@@ -13,6 +13,10 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
+    <modules>
+        <module>spring-flyway</module>
+    </modules>
+
     <dependencies>
         <dependency>
             <groupId>mysql</groupId>
@@ -20,6 +24,17 @@
             <version>${mysql.version}</version>
         </dependency>
     </dependencies>
+    <dependencyManagement>
+        <dependencies>
+            <dependency>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-dependencies</artifactId>
+                <version>${spring.boot.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+        </dependencies>
+    </dependencyManagement>
     <build>
         <plugins>
             <plugin>
@@ -32,5 +47,6 @@
     <properties>
         <mysql.version>6.0.5</mysql.version>
         <flyway-maven-plugin.version>4.0.3</flyway-maven-plugin.version>
+        <spring.boot.version>1.5.8.RELEASE</spring.boot.version>
     </properties>
 </project>

flyway/spring-flyway/.gitignore

@@ -0,0 +1,24 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+nbproject/private/
+build/
+nbbuild/
+dist/
+nbdist/
+.nb-gradle/

flyway/spring-flyway/pom.xml

@@ -0,0 +1,57 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<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>spring-flyway</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<packaging>jar</packaging>
+
+	<name>spring-flyway</name>
+	<description>Spring Boot Test Flyway Migrations</description>
+
+	<parent>
+		<artifactId>flyway</artifactId>
+		<groupId>com.baeldung</groupId>
+		<version>1.0</version>
+		<relativePath>../../flyway</relativePath>
+	</parent>
+
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+		<java.version>1.8</java.version>
+	</properties>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-data-jpa</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.flywaydb</groupId>
+			<artifactId>flyway-core</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.projectlombok</groupId>
+			<artifactId>lombok</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>com.h2database</groupId>
+			<artifactId>h2</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+			</plugin>
+		</plugins>
+	</build>
+</project>

flyway/spring-flyway/src/main/java/com/baeldung/springflyway/SpringFlywayApplication.java

@@ -0,0 +1,12 @@
+package com.baeldung.springflyway;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringFlywayApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpringFlywayApplication.class, args);
+    }
+}

flyway/spring-flyway/src/main/java/com/baeldung/springflyway/entities/Customer.java

@@ -0,0 +1,28 @@
+package com.baeldung.springflyway.entities;
+
+import lombok.AllArgsConstructor;
+import lombok.Builder;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Entity
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Builder
+public class Customer {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    private String firstName;
+    private String lastName;
+
+    private String email;
+
+}

flyway/spring-flyway/src/main/java/com/baeldung/springflyway/migration/V2__uk_lastname_customer.java

@@ -0,0 +1,14 @@
+package com.baeldung.springflyway.migration;
+
+import org.flywaydb.core.api.migration.spring.SpringJdbcMigration;
+import org.springframework.jdbc.core.JdbcTemplate;
+
+public class V2__uk_lastname_customer implements SpringJdbcMigration {
+
+    final String CUSTOMER_LASTNAME_UK = "ALTER TABLE customer  ADD CONSTRAINT uk_customer_lastname UNIQUE(last_name);";
+
+    @Override
+    public void migrate(final JdbcTemplate jdbcTemplate) throws Exception {
+        jdbcTemplate.execute(CUSTOMER_LASTNAME_UK);
+    }
+}

flyway/spring-flyway/src/main/java/com/baeldung/springflyway/repositories/CustomerRepository.java

@@ -0,0 +1,11 @@
+package com.baeldung.springflyway.repositories;
+
+import com.baeldung.springflyway.entities.Customer;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.Optional;
+
+public interface CustomerRepository extends JpaRepository<Customer, Long> {
+
+    Optional<Customer> findByEmail(String email);
+}

flyway/spring-flyway/src/test/java/com/baeldung/springflyway/CustomerRepositoryInitialMigrationTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.springflyway;
+
+import com.baeldung.springflyway.entities.Customer;
+import com.baeldung.springflyway.repositories.CustomerRepository;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.junit.Assert.assertNotNull;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class CustomerRepositoryInitialMigrationTest {
+
+    @Autowired CustomerRepository customerRepository;
+
+    @Test
+    public void givenSchemaCreationMigration_whenTryingToCreateACustomer_thenSuccess() {
+        Customer customer = customerRepository.save(Customer
+          .builder()
+          .email("customer@email.com")
+          .build());
+        assertNotNull(customer.getId());
+    }
+
+}

flyway/spring-flyway/src/test/java/com/baeldung/springflyway/CustomerRepositoryInsertDataMigrationTest.java

@@ -0,0 +1,35 @@
+package com.baeldung.springflyway;
+
+import com.baeldung.springflyway.entities.Customer;
+import com.baeldung.springflyway.repositories.CustomerRepository;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import java.util.List;
+import java.util.Optional;
+
+import static org.junit.Assert.*;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class CustomerRepositoryInsertDataMigrationTest {
+
+    @Autowired CustomerRepository customerRepository;
+
+    @Test
+    public void givenASetInsertData_whenRunningMigrationsWithSuccess_thenASpecificCustomerIsFound() {
+        Optional<Customer> customerOptional = customerRepository.findByEmail("email@email.com");
+        assertTrue(customerOptional.isPresent());
+    }
+
+    @Test
+    public void givenASetInsertData_whenRunningMigrationsWithSuccess_thenASetOfCustomersIsFound() {
+        List<Customer> customers = customerRepository.findAll();
+        assertNotNull(customers);
+        assertEquals(customers.size(), 6);
+    }
+
+}

flyway/spring-flyway/src/test/java/com/baeldung/springflyway/CustomerRepositoryNotNullConstraintMigrationTest.java

@@ -0,0 +1,25 @@
+package com.baeldung.springflyway;
+
+import com.baeldung.springflyway.entities.Customer;
+import com.baeldung.springflyway.repositories.CustomerRepository;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class CustomerRepositoryNotNullConstraintMigrationTest {
+
+    @Autowired CustomerRepository customerRepository;
+
+    @Test(expected = DataIntegrityViolationException.class)
+    public void givenTheNotNullConstraintMigrations_whenInsertingACustomerWithNullEmail_thenThrowException() {
+        customerRepository.save(Customer
+          .builder()
+          .build());
+    }
+
+}

flyway/spring-flyway/src/test/java/com/baeldung/springflyway/CustomerRepositoryUniqueConstraintJavaMigrationTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.springflyway;
+
+import com.baeldung.springflyway.entities.Customer;
+import com.baeldung.springflyway.repositories.CustomerRepository;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(properties = {
+  "flyway.locations[0]=db/migration", "flyway.locations[1]=com/baeldung/springflyway/migration"
+})
+public class CustomerRepositoryUniqueConstraintJavaMigrationTest {
+
+    @Autowired CustomerRepository customerRepository;
+
+    @Test(expected = DataIntegrityViolationException.class)
+    public void givenTheUniqueConstraintMigrations_whenInsertingAnExistingLastNameCustomer_thenThrowException() {
+        customerRepository.save(Customer
+          .builder()
+          .lastName("LastName")
+          .build());
+
+    }
+
+}

flyway/spring-flyway/src/test/java/com/baeldung/springflyway/CustomerRepositoryUniqueConstraintMigrationTest.java

@@ -0,0 +1,27 @@
+package com.baeldung.springflyway;
+
+import com.baeldung.springflyway.entities.Customer;
+import com.baeldung.springflyway.repositories.CustomerRepository;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+public class CustomerRepositoryUniqueConstraintMigrationTest {
+
+    @Autowired CustomerRepository customerRepository;
+
+    @Test(expected = DataIntegrityViolationException.class)
+    public void givenTheUniqueConstraintMigrations_whenInsertingAnExistingEmailCustomer_thenThrowException() {
+        customerRepository.save(Customer
+          .builder()
+          .email("email@email.com")
+          .build());
+
+    }
+
+}

flyway/spring-flyway/src/test/resources/application.properties

@@ -0,0 +1 @@
+spring.jpa.hibernate.ddl-auto=validate

flyway/spring-flyway/src/test/resources/db/migration/V1_0__create_table_customer.sql

@@ -0,0 +1,6 @@
+create table if not exists customer (
+  id bigint AUTO_INCREMENT not null primary key,
+  first_name varchar(255) ,
+  last_name  varchar(255) ,
+  email varchar(255)
+);

flyway/spring-flyway/src/test/resources/db/migration/V1_1__insert_customer.sql

@@ -0,0 +1,6 @@
+insert into customer (first_name, last_name, email) values ('FirstName', 'LastName', 'email@email.com');
+insert into customer (first_name, last_name, email) values ('FirstName1', 'LastName1', 'email1@email.com');
+insert into customer (first_name, last_name, email) values ('FirstName2', 'LastName2', 'email2@email.com');
+insert into customer (first_name, last_name, email) values ('FirstName3', 'LastName3', 'email3@email.com');
+insert into customer (first_name, last_name, email) values ('FirstName4', 'LastName4', 'email4@email.com');
+insert into customer (first_name, last_name, email) values ('FirstName5', 'LastName5', 'email5@email.com');

flyway/spring-flyway/src/test/resources/db/migration/V1_2__make_email_not_null.sql

@@ -0,0 +1 @@
+ALTER TABLE customer ALTER email SET NOT NULL;

flyway/spring-flyway/src/test/resources/db/migration/V1_3__make_email_unique.sql

@@ -0,0 +1 @@
+ALTER TABLE customer  ADD CONSTRAINT uk_customer_email UNIQUE(email);

gradle/README.md

@@ -1 +1,2 @@
 ## Relevant articles:
+- [Introduction to Gradle](http://www.baeldung.com/gradle)

gradle/plugin/build.gradle

@@ -0,0 +1,14 @@
+  repositories{
+      mavenCentral()
+  }
+  apply plugin: 'java'
+  apply plugin: 'maven'
+  apply plugin: com.baeldung.GreetingPlugin
+  dependencies {
+      compile gradleApi()
+  }
+
+  greeting {
+      greeter = "Stranger"
+      message = "Message from the build script!"
+  }

gradle/plugin/buildSrc/src/main/java/com/baeldung/GreetingPlugin.java

@@ -0,0 +1,17 @@
+package com.baeldung;
+
+import org.gradle.api.Plugin;
+import org.gradle.api.Project;
+
+public class GreetingPlugin implements Plugin<Project> {
+    @Override
+    public void apply(Project project) {
+
+        GreetingPluginExtension extension = project.getExtensions().create("greeting", GreetingPluginExtension.class);
+
+        project.task("hello").doLast(task -> {
+            System.out.println("Hello, " + extension.getGreeter());
+            System.out.println("I have a message for You: " + extension.getMessage()); }
+        );
+    }
+}

gradle/plugin/buildSrc/src/main/java/com/baeldung/GreetingPluginExtension.java

@@ -0,0 +1,22 @@
+package com.baeldung;
+
+public class GreetingPluginExtension {
+    private String greeter = "Baeldung";
+    private String message = "Message from Plugin!";
+
+    public String getGreeter() {
+        return greeter;
+    }
+
+    public void setGreeter(String greeter) {
+        this.greeter = greeter;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+}

guest/remote-debugging/README.md

@@ -0,0 +1,16 @@
+## Building
+
+To build the module, use Maven's `package` goal:
+
+```
+mvn clean package
+```
+
+The `war` file will be available at `target/remote-debugging.war`
+
+## Running
+
+The `war` application is deployed to Apache Tomcat 8 or any other Java Web or Application server. 
+To deploy it to the Apache Tomcat 8 server, drop it in the `tomcat/webapps` directory.
+
+The service then will be accessible at http://localhost:8080/remote-debugging/hello?name=John

guest/remote-debugging/pom.xml

@@ -0,0 +1,49 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.stackify</groupId>
+    <artifactId>java-remote-debugging</artifactId>
+    <version>0.0.1-SNAPSHOT</version>
+    <packaging>war</packaging>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>1.5.8.RELEASE</version>
+        <relativePath/> <!-- lookup parent from repository -->
+    </parent>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <java.version>1.8</java.version>
+    </properties>
+
+    <dependencies>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-web</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-tomcat</artifactId>
+            <scope>provided</scope>
+        </dependency>
+
+    </dependencies>
+
+    <build>
+        <finalName>remote-debugging</finalName>
+        <plugins>
+            <plugin>
+                <groupId>org.springframework.boot</groupId>
+                <artifactId>spring-boot-maven-plugin</artifactId>
+            </plugin>
+        </plugins>
+    </build>
+
+</project>

guest/remote-debugging/src/main/java/com/stackify/debug/JavaRemoteDebuggingApplication.java

@@ -0,0 +1,12 @@
+package com.stackify.debug;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class JavaRemoteDebuggingApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(JavaRemoteDebuggingApplication.class, args);
+    }
+}

guest/remote-debugging/src/main/java/com/stackify/debug/config/WebInitializer.java

@@ -0,0 +1,12 @@
+package com.stackify.debug.config;
+
+import com.stackify.debug.JavaRemoteDebuggingApplication;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.web.support.SpringBootServletInitializer;
+
+public class WebInitializer extends SpringBootServletInitializer {
+    @Override
+    protected SpringApplicationBuilder configure(SpringApplicationBuilder application) {
+        return application.sources(JavaRemoteDebuggingApplication.class);
+    }
+}

guest/remote-debugging/src/main/java/com/stackify/debug/rest/HelloController.java

@@ -0,0 +1,16 @@
+package com.stackify.debug.rest;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController("/hello")
+public class HelloController {
+
+    @GetMapping
+    public String hello(@RequestParam("name") String name) {
+        String message = "Hello, " + name;
+        return message;
+    }
+
+}

hibernate5/README.md

@@ -2,3 +2,5 @@
 
 - [Dynamic Mapping with Hibernate](http://www.baeldung.com/hibernate-dynamic-mapping)
 - [An Overview of Identifiers in Hibernate](http://www.baeldung.com/hibernate-identifiers)
+- [Hibernate – Mapping Date and Time](http://www.baeldung.com/hibernate-date-time)
+- [Hibernate Inheritance Mapping](http://www.baeldung.com/hibernate-inheritance)

hibernate5/src/main/java/com/baeldung/hibernate/HibernateUtil.java

@@ -6,6 +6,7 @@ import com.baeldung.hibernate.pojo.OrderEntry;
 import com.baeldung.hibernate.pojo.OrderEntryIdClass;
 import com.baeldung.hibernate.pojo.OrderEntryPK;
 import com.baeldung.hibernate.pojo.PointEntity;
+import com.baeldung.hibernate.pojo.PolygonEntity;
 import com.baeldung.hibernate.pojo.Product;
 import com.baeldung.hibernate.pojo.Phone;
 import com.baeldung.hibernate.pojo.TemporalValues;
@@ -79,6 +80,7 @@ public class HibernateUtil {
         metadataSources.addAnnotatedClass(Car.class);
         metadataSources.addAnnotatedClass(Bag.class);
         metadataSources.addAnnotatedClass(PointEntity.class);
+        metadataSources.addAnnotatedClass(PolygonEntity.class);
 
         Metadata metadata = metadataSources.buildMetadata();
         return metadata.getSessionFactoryBuilder()

hibernate5/src/main/java/com/baeldung/hibernate/pojo/PolygonEntity.java

@@ -0,0 +1,38 @@
+package com.baeldung.hibernate.pojo;
+
+import com.vividsolutions.jts.geom.Polygon;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Entity
+public class PolygonEntity {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    private Polygon polygon;
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public Polygon getPolygon() {
+        return polygon;
+    }
+
+    public void setPolygon(Polygon polygon) {
+        this.polygon = polygon;
+    }
+
+    @Override
+    public String toString() {
+        return "PolygonEntity{" + "id=" + id + ", polygon=" + polygon + '}';
+    }
+}

hibernate5/src/test/java/com/baeldung/hibernate/HibernateSpatialTest.java

@@ -1,10 +1,14 @@
 package com.baeldung.hibernate;
 
 import com.baeldung.hibernate.pojo.PointEntity;
+import com.baeldung.hibernate.pojo.PolygonEntity;
+import com.vividsolutions.jts.geom.Coordinate;
 import com.vividsolutions.jts.geom.Geometry;
 import com.vividsolutions.jts.geom.Point;
+import com.vividsolutions.jts.geom.Polygon;
 import com.vividsolutions.jts.io.ParseException;
 import com.vividsolutions.jts.io.WKTReader;
+import com.vividsolutions.jts.util.GeometricShapeFactory;
 import org.hibernate.Session;
 import org.hibernate.Transaction;
 import org.junit.After;
@@ -13,6 +17,7 @@ import org.junit.Test;
 
 import javax.persistence.Query;
 import java.io.IOException;
+import java.util.List;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.Assert.assertEquals;
@@ -82,16 +87,58 @@ public class HibernateSpatialTest {
           .containsOnly("POINT (1 1)", "POINT (1 2)", "POINT (3 4)");
     }
 
+    @Test
+    public void shouldSelectAllPointsWithinRadius() throws ParseException {
+        insertPoint("POINT (1 1)");
+        insertPoint("POINT (1 2)");
+        insertPoint("POINT (3 4)");
+        insertPoint("POINT (5 6)");
+
+        Query query = session.createQuery("select p from PointEntity p where within(p.point, :circle) = true",
+          PointEntity.class);
+        query.setParameter("circle", createCircle(0.0, 0.0, 5));
+
+        assertThat(query.getResultList().stream().map(p -> ((PointEntity) p).getPoint().toString()))
+          .containsOnly("POINT (1 1)", "POINT (1 2)");
+    }
+
+    @Test
+    public void shouldSelectAdjacentPolygons() throws ParseException {
+        insertPolygon("POLYGON ((0 0, 0 5, 5 5, 5 0, 0 0))");
+        insertPolygon("POLYGON ((3 0, 3 5, 8 5, 8 0, 3 0))");
+        insertPolygon("POLYGON ((2 2, 3 1, 2 5, 4 3, 3 3, 2 2))");
+
+        Query query = session.createQuery("select p from PolygonEntity p where touches(p.polygon, :polygon) = true",
+          PolygonEntity.class);
+        query.setParameter("polygon", wktToGeometry("POLYGON ((5 5, 5 10, 10 10, 10 5, 5 5))"));
+        assertThat(query.getResultList().stream().map(p -> ((PolygonEntity) p).getPolygon().toString()))
+          .containsOnly("POLYGON ((0 0, 0 5, 5 5, 5 0, 0 0))", "POLYGON ((3 0, 3 5, 8 5, 8 0, 3 0))");
+    }
+
     private void insertPoint(String point) throws ParseException {
         PointEntity entity = new PointEntity();
         entity.setPoint((Point) wktToGeometry(point));
         session.persist(entity);
     }
 
+    private void insertPolygon(String polygon) throws ParseException {
+        PolygonEntity entity = new PolygonEntity();
+        entity.setPolygon((Polygon) wktToGeometry(polygon));
+        session.persist(entity);
+    }
+
     private Geometry wktToGeometry(String wellKnownText) throws ParseException {
         WKTReader fromText = new WKTReader();
         Geometry geom = null;
         geom = fromText.read(wellKnownText);
         return geom;
     }
+
+    private static Geometry createCircle(double x, double y, double radius) {
+        GeometricShapeFactory shapeFactory = new GeometricShapeFactory();
+        shapeFactory.setNumPoints(32);
+        shapeFactory.setCentre(new Coordinate(x, y));
+        shapeFactory.setSize(radius * 2);
+        return shapeFactory.createCircle();
+    }
 }

jsonb/README.md

@@ -1 +1,4 @@
 ## JSON B
+
+## Relevant articles:
+- [Introduction to the JSON Binding API (JSR 367) in Java](http://www.baeldung.com/java-json-binding-api)

junit5/README.md

@@ -0,0 +1,2 @@
+## Relevant articles: 
+- [The Order of Tests in JUnit](http://www.baeldung.com/junit-5-test-order)

libraries/pom.xml

@@ -630,13 +630,13 @@
         <dependency>
           <groupId>com.google.http-client</groupId>
           <artifactId>google-http-client-jackson2</artifactId>
-            <version>${googleclient.version}</version>
+          <version>${googleclient.version}</version>
         </dependency>
         <dependency>
-        <groupId>com.google.http-client</groupId>
-        <artifactId>google-http-client-gson</artifactId>
-        <version>${googleclient.version}</version>
-      </dependency>
+            <groupId>com.google.http-client</groupId>
+            <artifactId>google-http-client-gson</artifactId>
+            <version>${googleclient.version}</version>
+        </dependency>
     </dependencies>
     <repositories>
         <repository>

logging-modules/logback/src/main/java/com/baeldung/logback/MapAppender.java

@@ -3,12 +3,14 @@ package com.baeldung.logback;
 import ch.qos.logback.classic.spi.ILoggingEvent;
 import ch.qos.logback.core.AppenderBase;
 
-import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.ConcurrentMap;
 
 public class MapAppender extends AppenderBase<ILoggingEvent> {
 
-    private final Map<String, ILoggingEvent> eventMap = new HashMap<>();
+    private final ConcurrentMap<String, ILoggingEvent> eventMap
+      = new ConcurrentHashMap<>();
 
     private String prefix;
 

osgi/readme.md

@@ -86,6 +86,9 @@ org.eclipse.osgi_3.12.1.v20170821-1548.jar
 
  = = NOT GOOD = =
  
+ ## Relevant articles:
+ - [Introduction to OSGi](http://www.baeldung.com/osgi)
+ 
 
 
 

patterns/README.md

@@ -1,4 +1,5 @@
 ###Relevant Articles:
 - [A Guide to the Front Controller Pattern in Java](http://www.baeldung.com/java-front-controller-pattern)
 - [Introduction to Intercepting Filter Pattern in Java](http://www.baeldung.com/intercepting-filter-pattern-in-java)
-- [Implementing the Template Method Pattern in Java](http://www.baeldung.com/template-method-pattern-in-java)
+- [Implementing the Template Method Pattern in Java](http://www.baeldung.com/java-template-method-pattern)
+

persistence-modules/spring-jpa/README.md

@@ -15,6 +15,7 @@
 - [Deleting Objects with Hibernate](http://www.baeldung.com/delete-with-hibernate)
 - [Self-Contained Testing Using an In-Memory Database](http://www.baeldung.com/spring-jpa-test-in-memory-database)
 - [Spring Data JPA – Adding a Method in All Repositories](http://www.baeldung.com/spring-data-jpa-method-in-all-repositories)
+- [A Guide to Spring AbstractRoutingDatasource](http://www.baeldung.com/spring-abstract-routing-data-source)
 
 ### Eclipse Config 
 After importing the project into Eclipse, you may see the following error:  

pom.xml

@@ -203,6 +203,7 @@
         <module>spring-rest-query-language</module>
         <module>spring-rest</module>
         <module>spring-rest-simple</module>
+        <module>spring-security-acl</module>
         <module>spring-security-cache-control</module>
         <module>spring-security-client/spring-security-jsp-authentication</module>
         <module>spring-security-client/spring-security-jsp-authorize</module>

spring-5/README.md

@@ -11,3 +11,5 @@ The "REST With Spring" Classes: http://bit.ly/restwithspring
 - [Spring 5 WebClient](http://www.baeldung.com/spring-5-webclient)
 - [Spring 5 Functional Bean Registration](http://www.baeldung.com/spring-5-functional-beans)
 - [The SpringJUnitConfig and SpringJUnitWebConfig Annotations in Spring 5](http://www.baeldung.com/spring-5-junit-config)
+- [Spring Security 5 for Reactive Applications](http://www.baeldung.com/spring-security-5-reactive)
+- [Spring 5 Testing with @EnabledIf Annotation](https://github.com/eugenp/tutorials/tree/master/spring-5)

spring-5/pom.xml

@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.0.0.M6</version>
+		<version>2.0.0.M7</version>
 		<relativePath /> <!-- lookup parent from repository -->
 	</parent>
 

spring-aop/README.md

@@ -2,4 +2,5 @@
 
 - [Implementing a Custom Spring AOP Annotation](http://www.baeldung.com/spring-aop-annotation)
 - [Intro to AspectJ](http://www.baeldung.com/aspectj)
-- [Spring Performance Logging](http://www.baeldung.com/spring-performance-logging)
+- [Spring Performance Logging](http://www.baeldung.com/spring-performance-logging)
+- [Introduction to Spring AOP](http://www.baeldung.com/spring-aop)

spring-boot-keycloak/README.md

@@ -0,0 +1,2 @@
+## Relevant articles:
+- [A Quick Guide to Using Keycloak with Spring Boot](http://www.baeldung.com/spring-boot-keycloak)

spring-boot/README.MD

@@ -28,4 +28,4 @@ The "REST With Spring" Classes: http://bit.ly/restwithspring
 - [Spring Boot and Togglz Aspect](http://www.baeldung.com/spring-togglz)
 - [Getting Started with GraphQL and Spring Boot](http://www.baeldung.com/spring-graphql)
 - [Guide to Spring Type Conversions](http://www.baeldung.com/spring-type-conversions)
-
+- [Quick Guide on data.sql and schema.sql Files in Spring Boot](http://www.baeldung.com/spring-boot-data-sql-and-schema-sql)

spring-cloud-cli/README.md

@@ -3,4 +3,4 @@
 ## Spring Cloud CLI
 
 ### Relevant Articles: 
-- [Introduction to Spring Cloud CLI](http://www.baeldung.com/introduction-to-spring-cloud-cli/)
+- [Introduction to Spring Cloud CLI](http://www.baeldung.com/spring-cloud-cli)

spring-cloud/README.md

@@ -15,6 +15,7 @@
 - [Intro to Spring Cloud Netflix - Hystrix](http://www.baeldung.com/spring-cloud-netflix-hystrix)
 - [Dockerizing a Spring Boot Application](http://www.baeldung.com/dockerizing-spring-boot-application)
 - [Introduction to Spring Cloud Rest Client with Netflix Ribbon](http://www.baeldung.com/spring-cloud-rest-client-with-netflix-ribbon)
+- [A Quick Guide to Spring Cloud Consul](http://www.baeldung.com/spring-cloud-consul)
 
 ### Relevant Articles:
 - [Introduction to Spring Cloud Rest Client with Netflix Ribbon](http://www.baeldung.com/spring-cloud-rest-client-with-netflix-ribbon)

spring-core/README.md

@@ -8,3 +8,5 @@
 - [Spring YAML Configuration](http://www.baeldung.com/spring-yaml)
 - [Introduction to Spring’s StreamUtils](http://www.baeldung.com/spring-stream-utils)
 - [Using Spring @Value with Defaults](http://www.baeldung.com/spring-value-defaults)
+- [Groovy Bean Definitions](http://www.baeldung.com/spring-groovy-beans)
+- [XML-Based Injection in Spring](http://www.baeldung.com/spring-xml-injection)

spring-hibernate3/README.md

@@ -0,0 +1,2 @@
+## Relevant articles:
+- [HibernateException: No Hibernate Session Bound to Thread in Hibernate 3](http://www.baeldung.com/no-hibernate-session-bound-to-thread-exception)

spring-integration/README.md

@@ -1,2 +1,5 @@
 ### Relevant Articles:
 - [Introduction to Spring Integration](http://www.baeldung.com/spring-integration)
+
+### Running the Sample
+Executing the `mvn exec:java` maven command (either from the command line or from an IDE) will start up the application. Follow the command prompt for further instructions.

spring-integration/pom.xml

@@ -22,7 +22,7 @@
         <spring-social.version>1.1.4.RELEASE</spring-social.version>
         <javax-mail.version>1.4.7</javax-mail.version>
         <javax-activation.version>1.1.1</javax-activation.version>
-
+        <junit.version>4.12</junit.version>
         <maven-eclipse-plugin.version>2.10</maven-eclipse-plugin.version>
         <exec-maven-plugin.version>1.5.0</exec-maven-plugin.version>
     </properties>
@@ -56,7 +56,7 @@
                 <artifactId>exec-maven-plugin</artifactId>
                 <version>${exec-maven-plugin.version}</version>
                 <configuration>
-                    <mainClass>com.baeldung.samples.Main</mainClass>
+                    <mainClass>com.baeldung.samples.FileCopyConfig</mainClass>
                 </configuration>
             </plugin>
         </plugins>
@@ -106,6 +106,12 @@
             <artifactId>spring-integration-file</artifactId>
             <version>${spring.integration.version}</version>
         </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <profiles>