[BAEL-2533] fix merge conflict

.gitignore

@@ -66,3 +66,10 @@ jmeter/src/main/resources/*-JMeter.csv
 **/nb-configuration.xml
 core-scala/.cache-main
 core-scala/.cache-tests
+
+
+persistence-modules/hibernate5/transaction.log
+apache-avro/src/main/java/com/baeldung/avro/model/
+jta/transaction-logs/
+software-security/sql-injection-samples/derby.log
+spring-soap/src/main/java/com/baeldung/springsoap/gen/

JGit/pom.xml

@@ -5,9 +5,9 @@
     <groupId>com.baeldung</groupId>
     <artifactId>JGit</artifactId>
     <version>1.0-SNAPSHOT</version>
+	<name>JGit</name>
     <packaging>jar</packaging>
     <url>http://maven.apache.org</url>
-	<name>JGit</name>
 
     <parent>
         <groupId>com.baeldung</groupId>

README.md

@@ -14,7 +14,7 @@ Java and Spring Tutorials
 ================
 
 This project is **a collection of small and focused tutorials** - each covering a single and well defined area of development in the Java ecosystem. 
-A strong focus of these is, of course, the Spring Framework - Spring, Spring Boot and Spring Securiyt. 
+A strong focus of these is, of course, the Spring Framework - Spring, Spring Boot and Spring Security. 
 In additional to Spring, the following technologies are in focus: `core Java`, `Jackson`, `HttpClient`, `Guava`. 
 
 

Twitter4J/pom.xml

@@ -2,8 +2,8 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <artifactId>Twitter4J</artifactId>
-    <packaging>jar</packaging>
     <name>Twitter4J</name>
+    <packaging>jar</packaging>
 
     <parent>
         <groupId>com.baeldung</groupId>

akka-http/README.md

@@ -0,0 +1,3 @@
+## Relevant articles:
+
+- [Introduction to Akka HTTP](https://www.baeldung.com/akka-http)

akka-http/pom.xml

@@ -0,0 +1,48 @@
+<?xml version="1.0"?>
+<project
+	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"
+	xmlns="http://maven.apache.org/POM/4.0.0"
+	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+
+	<modelVersion>4.0.0</modelVersion>
+	<artifactId>akka-http</artifactId>
+	<name>akka-http</name>
+
+	<parent>
+		<artifactId>parent-modules</artifactId>
+		<groupId>com.baeldung</groupId>
+		<version>1.0.0-SNAPSHOT</version>
+	</parent>
+
+	<dependencies>
+		<dependency>
+			<groupId>com.typesafe.akka</groupId>
+			<artifactId>akka-http_2.12</artifactId>
+			<version>${akka.http.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>com.typesafe.akka</groupId>
+			<artifactId>akka-stream_2.12</artifactId>
+			<version>${akka.stream.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>com.typesafe.akka</groupId>
+			<artifactId>akka-http-jackson_2.12</artifactId>
+			<version>${akka.http.version}</version>
+		</dependency>
+		<dependency>
+			<groupId>com.typesafe.akka</groupId>
+			<artifactId>akka-http-testkit_2.12</artifactId>
+			<version>${akka.http.version}</version>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<properties>
+		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+		<java.version>1.8</java.version>
+		<akka.http.version>10.0.11</akka.http.version>
+		<akka.stream.version>2.5.11</akka.stream.version>
+	</properties>
+</project>

akka-http/src/main/java/com/baeldung/akkahttp/User.java

@@ -0,0 +1,26 @@
+package com.baeldung.akkahttp;
+
+public class User {
+
+    private final Long id;
+
+    private final String name;
+
+    public User() {
+        this.name = "";
+        this.id = null;
+    }
+
+    public User(Long id, String name) {
+        this.name = name;
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public Long getId() {
+        return id;
+    }
+}

akka-http/src/main/java/com/baeldung/akkahttp/UserActor.java

@@ -0,0 +1,41 @@
+package com.baeldung.akkahttp;
+
+import akka.actor.AbstractActor;
+import akka.actor.Props;
+import akka.japi.pf.FI;
+import com.baeldung.akkahttp.UserMessages.ActionPerformed;
+import com.baeldung.akkahttp.UserMessages.CreateUserMessage;
+import com.baeldung.akkahttp.UserMessages.GetUserMessage;
+
+
+class UserActor extends AbstractActor {
+
+  private UserService userService = new UserService();
+
+  static Props props() {
+    return Props.create(UserActor.class);
+  }
+
+  @Override
+  public Receive createReceive() {
+    return receiveBuilder()
+            .match(CreateUserMessage.class, handleCreateUser())
+            .match(GetUserMessage.class, handleGetUser())
+            .build();
+  }
+
+  private FI.UnitApply<CreateUserMessage> handleCreateUser() {
+    return createUserMessageMessage -> {
+      userService.createUser(createUserMessageMessage.getUser());
+      sender().tell(new ActionPerformed(String.format("User %s created.", createUserMessageMessage.getUser()
+              .getName())), getSelf());
+    };
+  }
+
+  private FI.UnitApply<GetUserMessage> handleGetUser() {
+    return getUserMessageMessage -> {
+      sender().tell(userService.getUser(getUserMessageMessage.getUserId()), getSelf());
+    };
+  }
+
+}

akka-http/src/main/java/com/baeldung/akkahttp/UserMessages.java

@@ -0,0 +1,49 @@
+package com.baeldung.akkahttp;
+
+import java.io.Serializable;
+
+public interface UserMessages {
+
+  class ActionPerformed implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+
+    private final String description;
+
+    public ActionPerformed(String description) {
+      this.description = description;
+    }
+
+    public String getDescription() {
+      return description;
+    }
+  }
+
+  class CreateUserMessage implements Serializable {
+
+    private static final long serialVersionUID = 1L;
+    private final User user;
+
+    public CreateUserMessage(User user) {
+      this.user = user;
+    }
+
+    public User getUser() {
+      return user;
+    }
+  }
+
+  class GetUserMessage implements Serializable {
+    private static final long serialVersionUID = 1L;
+    private final Long userId;
+
+    public GetUserMessage(Long userId) {
+      this.userId = userId;
+    }
+
+    public Long getUserId() {
+      return userId;
+    }
+  }
+
+}

akka-http/src/main/java/com/baeldung/akkahttp/UserServer.java

@@ -0,0 +1,70 @@
+package com.baeldung.akkahttp;
+
+import java.util.Optional;
+import java.util.concurrent.CompletionStage;
+import java.util.concurrent.TimeUnit;
+
+import akka.actor.ActorRef;
+import akka.actor.ActorSystem;
+import akka.http.javadsl.marshallers.jackson.Jackson;
+import akka.http.javadsl.model.StatusCodes;
+import akka.http.javadsl.server.HttpApp;
+import akka.http.javadsl.server.Route;
+import akka.pattern.PatternsCS;
+import akka.util.Timeout;
+import com.baeldung.akkahttp.UserMessages.ActionPerformed;
+import com.baeldung.akkahttp.UserMessages.CreateUserMessage;
+import com.baeldung.akkahttp.UserMessages.GetUserMessage;
+import scala.concurrent.duration.Duration;
+import static akka.http.javadsl.server.PathMatchers.*;
+
+class UserServer extends HttpApp {
+
+  private final ActorRef userActor;
+
+  Timeout timeout = new Timeout(Duration.create(5, TimeUnit.SECONDS));
+
+  UserServer(ActorRef userActor) {
+    this.userActor = userActor;
+  }
+
+  @Override
+  public Route routes() {
+    return path("users", this::postUser)
+            .orElse(path(segment("users").slash(longSegment()), id ->
+                    route(getUser(id))));
+  }
+
+  private Route getUser(Long id) {
+    return get(() -> {
+      CompletionStage<Optional<User>> user = PatternsCS.ask(userActor, new GetUserMessage(id), timeout)
+              .thenApply(obj -> (Optional<User>) obj);
+
+      return onSuccess(() -> user, performed -> {
+        if (performed.isPresent())
+          return complete(StatusCodes.OK, performed.get(), Jackson.marshaller());
+        else
+          return complete(StatusCodes.NOT_FOUND);
+      });
+    });
+  }
+
+  private Route postUser() {
+    return route(post(() -> entity(Jackson.unmarshaller(User.class), user -> {
+      CompletionStage<ActionPerformed> userCreated = PatternsCS.ask(userActor, new CreateUserMessage(user), timeout)
+              .thenApply(obj -> (ActionPerformed) obj);
+
+      return onSuccess(() -> userCreated, performed -> {
+        return complete(StatusCodes.CREATED, performed, Jackson.marshaller());
+      });
+    })));
+  }
+
+  public static void main(String[] args) throws Exception {
+    ActorSystem system = ActorSystem.create("userServer");
+    ActorRef userActor = system.actorOf(UserActor.props(), "userActor");
+    UserServer server = new UserServer(userActor);
+    server.startServer("localhost", 8080, system);
+  }
+
+}

akka-http/src/main/java/com/baeldung/akkahttp/UserService.java

@@ -0,0 +1,35 @@
+package com.baeldung.akkahttp;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Optional;
+
+public class UserService {
+
+  private final static List<User> users = new ArrayList<>();
+
+  static {
+    users.add(new User(1l, "Alice"));
+    users.add(new User(2l, "Bob"));
+    users.add(new User(3l, "Chris"));
+    users.add(new User(4l, "Dick"));
+    users.add(new User(5l, "Eve"));
+    users.add(new User(6l, "Finn"));
+  }
+
+  public Optional<User> getUser(Long id) {
+    return users.stream()
+            .filter(user -> user.getId()
+                    .equals(id))
+            .findFirst();
+  }
+
+  public void createUser(User user) {
+    users.add(user);
+  }
+
+  public List<User> getUsers(){
+    return users;
+  }
+
+}

akka-http/src/test/java/com/baeldung/akkahttp/UserServerUnitTest.java

@@ -0,0 +1,50 @@
+package com.baeldung.akkahttp;
+
+import akka.actor.ActorRef;
+import akka.actor.ActorSystem;
+import akka.http.javadsl.model.ContentTypes;
+import akka.http.javadsl.model.HttpEntities;
+import akka.http.javadsl.model.HttpRequest;
+import akka.http.javadsl.testkit.JUnitRouteTest;
+import akka.http.javadsl.testkit.TestRoute;
+import org.junit.Test;
+
+public class UserServerUnitTest extends JUnitRouteTest {
+
+  ActorSystem system = ActorSystem.create("helloAkkaHttpServer");
+
+  ActorRef userActorRef = system.actorOf(UserActor.props(), "userActor");
+
+  TestRoute appRoute = testRoute(new UserServer(userActorRef).routes());
+
+  @Test
+  public void whenRequest_thenActorResponds() {
+
+    appRoute.run(HttpRequest.GET("/users/1"))
+            .assertEntity(alice())
+            .assertStatusCode(200);
+
+    appRoute.run(HttpRequest.GET("/users/42"))
+            .assertStatusCode(404);
+
+    appRoute.run(HttpRequest.DELETE("/users/1"))
+            .assertStatusCode(200);
+
+    appRoute.run(HttpRequest.DELETE("/users/42"))
+            .assertStatusCode(200);
+
+    appRoute.run(HttpRequest.POST("/users")
+            .withEntity(HttpEntities.create(ContentTypes.APPLICATION_JSON, zaphod())))
+            .assertStatusCode(201);
+
+  }
+
+  private String alice() {
+    return "{\"id\":1,\"name\":\"Alice\"}";
+  }
+
+  private String zaphod() {
+    return "{\"id\":42,\"name\":\"Zaphod\"}";
+  }
+
+}

algorithms-miscellaneous-1/README.md

@@ -10,4 +10,10 @@
 - [Multi-Swarm Optimization Algorithm in Java](http://www.baeldung.com/java-multi-swarm-algorithm)
 - [String Search Algorithms for Large Texts](http://www.baeldung.com/java-full-text-search-algorithms)
 - [Check If a String Contains All The Letters of The Alphabet](https://www.baeldung.com/java-string-contains-all-letters)
-- [Find the Middle Element of a Linked List](http://www.baeldung.com/java-linked-list-middle-element)
+- [Find the Middle Element of a Linked List](http://www.baeldung.com/java-linked-list-middle-element)
+- [Calculate Factorial in Java](https://www.baeldung.com/java-calculate-factorial)
+- [Find Substrings That Are Palindromes in Java](https://www.baeldung.com/java-palindrome-substrings)
+- [Find the Longest Substring without Repeating Characters](https://www.baeldung.com/java-longest-substring-without-repeated-characters)
+- [Java Two Pointer Technique](https://www.baeldung.com/java-two-pointer-technique)
+- [Permutations of an Array in Java](https://www.baeldung.com/java-array-permutations)
+- [Implementing Simple State Machines with Java Enums](https://www.baeldung.com/java-enum-simple-state-machine)

algorithms-miscellaneous-1/src/main/java/com/baeldung/algorithms/enumstatemachine/LeaveRequestState.java

@@ -0,0 +1,46 @@
+package com.baeldung.algorithms.enumstatemachine;
+
+public enum LeaveRequestState {
+
+    Submitted {
+        @Override
+        public LeaveRequestState nextState() {
+            System.out.println("Starting the Leave Request and sending to Team Leader for approval.");
+            return Escalated;
+        }
+
+        @Override
+        public String responsiblePerson() {
+            return "Employee";
+        }
+    },
+    Escalated {
+        @Override
+        public LeaveRequestState nextState() {
+            System.out.println("Reviewing the Leave Request and escalating to Department Manager.");
+            return Approved;
+        }
+
+        @Override
+        public String responsiblePerson() {
+            return "Team Leader";
+        }
+    },
+    Approved {
+        @Override
+        public LeaveRequestState nextState() {
+            System.out.println("Approving the Leave Request.");
+            return this;
+        }
+
+        @Override
+        public String responsiblePerson() {
+            return "Department Manager";
+        }
+    };
+
+    public abstract String responsiblePerson();
+
+    public abstract LeaveRequestState nextState();
+
+}

algorithms-miscellaneous-1/src/main/java/com/baeldung/algorithms/permutation/Permutation.java

@@ -0,0 +1,123 @@
+package com.baeldung.algorithms.permutation;
+
+import java.util.Arrays;
+import java.util.Collections;
+
+public  class Permutation {
+
+    public static <T> void printAllRecursive(T[] elements, char delimiter) {
+        printAllRecursive(elements.length, elements, delimiter);
+    }
+
+    public static <T> void printAllRecursive(int n, T[] elements, char delimiter) {
+
+        if(n == 1) {
+            printArray(elements, delimiter);
+        } else {
+            for(int i = 0; i < n-1; i++) {
+                printAllRecursive(n - 1, elements, delimiter);
+                if(n % 2 == 0) {
+                    swap(elements, i, n-1);
+                } else {
+                    swap(elements, 0, n-1);
+                }
+            }
+            printAllRecursive(n - 1, elements, delimiter);
+        }
+    }
+
+    public static <T> void printAllIterative(int n, T[] elements, char delimiter) {
+
+        int[] indexes = new int[n];
+        for (int i = 0; i < n; i++) {
+            indexes[i] = 0;
+        }
+
+        printArray(elements, delimiter);
+
+        int i = 0;
+        while (i < n) {
+            if (indexes[i] < i) {
+                swap(elements, i % 2 == 0 ?  0: indexes[i], i);
+                printArray(elements, delimiter);
+                indexes[i]++;
+                i = 0;
+            }
+            else {
+                indexes[i] = 0;
+                i++;
+            }
+        }
+    }
+
+    public static <T extends Comparable<T>> void printAllOrdered(T[] elements, char delimiter) {
+
+        Arrays.sort(elements);
+        boolean hasNext = true;
+
+        while(hasNext) {
+            printArray(elements, delimiter);
+            int k = 0, l = 0;
+            hasNext = false;
+            for (int i = elements.length - 1; i > 0; i--) {
+                if (elements[i].compareTo(elements[i - 1]) > 0) {
+                    k = i - 1;
+                    hasNext = true;
+                    break;
+                }
+            }
+
+            for (int i = elements.length - 1; i > k; i--) {
+                if (elements[i].compareTo(elements[k]) > 0) {
+                    l = i;
+                    break;
+                }
+            }
+
+            swap(elements, k, l);
+            Collections.reverse(Arrays.asList(elements).subList(k + 1, elements.length));
+        }
+    }
+
+    public static <T> void printRandom(T[] elements, char delimiter) {
+
+        Collections.shuffle(Arrays.asList(elements));
+        printArray(elements, delimiter);
+    }
+
+    private static <T> void swap(T[] elements, int a, int b) {
+
+        T tmp = elements[a];
+        elements[a] = elements[b];
+        elements[b] = tmp;
+    }
+
+    private static <T> void printArray(T[] elements, char delimiter) {
+
+        String delimiterSpace = delimiter + " ";
+        for(int i = 0; i < elements.length; i++) {
+            System.out.print(elements[i] + delimiterSpace);
+        }
+        System.out.print('\n');
+    }
+
+    public static void main(String[] argv) {
+
+        Integer[] elements = {1,2,3,4};
+
+        System.out.println("Rec:");
+        printAllRecursive(elements, ';');
+
+        System.out.println("Iter:");
+        printAllIterative(elements.length, elements, ';');
+
+        System.out.println("Orderes:");
+        printAllOrdered(elements, ';');
+
+        System.out.println("Random:");
+        printRandom(elements, ';');
+
+        System.out.println("Random:");
+        printRandom(elements, ';');
+    }
+}

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

@@ -1,4 +1,4 @@
-package com.baeldung.string;
+package com.baeldung.algorithms.string;
 
 import java.util.HashSet;
 import java.util.Set;

algorithms-miscellaneous-1/src/main/java/com/baeldung/algorithms/twopointertechnique/LinkedListFindMiddle.java

@@ -0,0 +1,16 @@
+package com.baeldung.algorithms.twopointertechnique;
+
+public class LinkedListFindMiddle {
+
+    public <T> T findMiddle(MyNode<T> head) {
+        MyNode<T> slowPointer = head;
+        MyNode<T> fastPointer = head;
+
+        while (fastPointer.next != null && fastPointer.next.next != null) {
+            fastPointer = fastPointer.next.next;
+            slowPointer = slowPointer.next;
+        }
+        return slowPointer.data;
+    }
+
+}

algorithms-miscellaneous-1/src/main/java/com/baeldung/algorithms/twopointertechnique/MyNode.java

@@ -0,0 +1,20 @@
+package com.baeldung.algorithms.twopointertechnique;
+
+public class MyNode<E> {
+    MyNode<E> next;
+    E data;
+
+    public MyNode(E value) {
+        data = value;
+        next = null;
+    }
+
+    public MyNode(E value, MyNode<E> n) {
+        data = value;
+        next = n;
+    }
+
+    public void setNext(MyNode<E> n) {
+        next = n;
+    }
+}

algorithms-miscellaneous-1/src/main/java/com/baeldung/algorithms/twopointertechnique/RotateArray.java

@@ -0,0 +1,22 @@
+package com.baeldung.algorithms.twopointertechnique;
+
+public class RotateArray {
+
+    public void rotate(int[] input, int step) {
+        step %= input.length;
+        reverse(input, 0, input.length - 1);
+        reverse(input, 0, step - 1);
+        reverse(input, step, input.length - 1);
+    }
+
+    private void reverse(int[] input, int start, int end) {
+        while (start < end) {
+            int temp = input[start];
+            input[start] = input[end];
+            input[end] = temp;
+            start++;
+            end--;
+        }
+    }
+
+}

algorithms-miscellaneous-1/src/main/java/com/baeldung/algorithms/twopointertechnique/TwoSum.java

@@ -0,0 +1,38 @@
+package com.baeldung.algorithms.twopointertechnique;
+
+public class TwoSum {
+
+    public boolean twoSum(int[] input, int targetValue) {
+
+        int pointerOne = 0;
+        int pointerTwo = input.length - 1;
+
+        while (pointerOne < pointerTwo) {
+            int sum = input[pointerOne] + input[pointerTwo];
+
+            if (sum == targetValue) {
+                return true;
+            } else if (sum < targetValue) {
+                pointerOne++;
+            } else {
+                pointerTwo--;
+            }
+        }
+
+        return false;
+    }
+
+    public boolean twoSumSlow(int[] input, int targetValue) {
+
+        for (int i = 0; i < input.length; i++) {
+            for (int j = 1; j < input.length; j++) {
+                if (input[i] + input[j] == targetValue) {
+                    return true;
+                }
+            }
+        }
+
+        return false;
+    }
+
+}

algorithms-miscellaneous-1/src/test/java/com/baeldung/algorithms/enumstatemachine/LeaveRequestStateUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.algorithms.enumstatemachine;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class LeaveRequestStateUnitTest {
+
+    @Test
+    public void givenLeaveRequest_whenStateEscalated_thenResponsibleIsTeamLeader() {
+        LeaveRequestState state = LeaveRequestState.Escalated;
+
+        assertEquals(state.responsiblePerson(), "Team Leader");
+    }
+
+
+    @Test
+    public void givenLeaveRequest_whenStateApproved_thenResponsibleIsDepartmentManager() {
+        LeaveRequestState state = LeaveRequestState.Approved;
+
+        assertEquals(state.responsiblePerson(), "Department Manager");
+    }
+
+    @Test
+    public void givenLeaveRequest_whenNextStateIsCalled_thenStateIsChanged() {
+        LeaveRequestState state = LeaveRequestState.Submitted;
+
+        state = state.nextState();
+        assertEquals(state, LeaveRequestState.Escalated);
+
+        state = state.nextState();
+        assertEquals(state, LeaveRequestState.Approved);
+
+        state = state.nextState();
+        assertEquals(state, LeaveRequestState.Approved);
+    }
+}

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

@@ -1,4 +1,4 @@
-package com.baeldung.string;
+package com.baeldung.algorithms.string;
 
 import static org.junit.Assert.assertEquals;
 import java.util.HashSet;

algorithms-miscellaneous-1/src/test/java/com/baeldung/algorithms/twopointertechnique/LinkedListFindMiddleUnitTest.java

@@ -0,0 +1,37 @@
+package com.baeldung.algorithms.twopointertechnique;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+
+public class LinkedListFindMiddleUnitTest {
+
+    LinkedListFindMiddle linkedListFindMiddle = new LinkedListFindMiddle();
+
+    @Test
+    public void givenLinkedListOfMyNodes_whenLinkedListFindMiddle_thenCorrect() {
+
+        MyNode<String> head = createNodesList(8);
+
+        assertThat(linkedListFindMiddle.findMiddle(head)).isEqualTo("4");
+
+        head = createNodesList(9);
+
+        assertThat(linkedListFindMiddle.findMiddle(head)).isEqualTo("5");
+    }
+
+    private static MyNode<String> createNodesList(int n) {
+
+        MyNode<String> head = new MyNode<String>("1");
+        MyNode<String> current = head;
+
+        for (int i = 2; i <= n; i++) {
+            MyNode<String> newNode = new MyNode<String>(String.valueOf(i));
+            current.setNext(newNode);
+            current = newNode;
+        }
+
+        return head;
+    }
+
+}

algorithms-miscellaneous-1/src/test/java/com/baeldung/algorithms/twopointertechnique/RotateArrayUnitTest.java

@@ -0,0 +1,26 @@
+package com.baeldung.algorithms.twopointertechnique;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.Test;
+
+public class RotateArrayUnitTest {
+
+    private RotateArray rotateArray = new RotateArray();
+
+    private int[] inputArray;
+
+    private int step;
+
+    @Test
+    public void givenAnArrayOfIntegers_whenRotateKsteps_thenCorrect() {
+
+        inputArray = new int[] { 1, 2, 3, 4, 5, 6, 7 };
+        step = 4;
+
+        rotateArray.rotate(inputArray, step);
+
+        assertThat(inputArray).containsExactly(new int[] { 4, 5, 6, 7, 1, 2, 3 });
+    }
+
+}

algorithms-miscellaneous-1/src/test/java/com/baeldung/algorithms/twopointertechnique/TwoSumUnitTest.java

@@ -0,0 +1,56 @@
+package com.baeldung.algorithms.twopointertechnique;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+import org.junit.Test;
+
+public class TwoSumUnitTest {
+
+    private TwoSum twoSum = new TwoSum();
+
+    private int[] sortedArray;
+
+    private int targetValue;
+
+    @Test
+    public void givenASortedArrayOfIntegers_whenTwoSumSlow_thenPairExists() {
+
+        sortedArray = new int[] { 0, 1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 9 };
+
+        targetValue = 12;
+
+        assertTrue(twoSum.twoSumSlow(sortedArray, targetValue));
+    }
+
+    @Test
+    public void givenASortedArrayOfIntegers_whenTwoSumSlow_thenPairDoesNotExists() {
+
+        sortedArray = new int[] { 0, 1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 9 };
+
+        targetValue = 20;
+
+        assertFalse(twoSum.twoSumSlow(sortedArray, targetValue));
+    }
+
+    @Test
+    public void givenASortedArrayOfIntegers_whenTwoSum_thenPairExists() {
+
+        sortedArray = new int[] { 0, 1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 9 };
+
+        targetValue = 12;
+
+        assertTrue(twoSum.twoSum(sortedArray, targetValue));
+    }
+
+    @Test
+    public void givenASortedArrayOfIntegers_whenTwoSum_thenPairDoesNotExists() {
+
+        sortedArray = new int[] { 0, 1, 2, 3, 4, 5, 5, 6, 7, 8, 9, 9 };
+
+        targetValue = 20;
+
+        assertFalse(twoSum.twoSum(sortedArray, targetValue));
+    }
+
+}

algorithms-miscellaneous-2/pom.xml

@@ -33,6 +33,11 @@
             <artifactId>jgrapht-core</artifactId>
             <version>${org.jgrapht.core.version}</version>
         </dependency>
+        <dependency>
+        	<groupId>org.jgrapht</groupId>
+        	<artifactId>jgrapht-ext</artifactId>
+        	<version>${org.jgrapht.ext.version}</version>
+        </dependency>
         <dependency>
             <groupId>pl.allegro.finance</groupId>
             <artifactId>tradukisto</artifactId>
@@ -63,7 +68,7 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>cobertura-maven-plugin</artifactId>
-                <version>2.7</version>
+                <version>${cobertura-maven-plugin.version}</version>
                 <configuration>
                     <instrumentation>
                         <ignores>
@@ -83,8 +88,10 @@
         <commons-math3.version>3.6.1</commons-math3.version>
         <tradukisto.version>1.0.1</tradukisto.version>
         <org.jgrapht.core.version>1.0.1</org.jgrapht.core.version>
+        <org.jgrapht.ext.version>1.0.1</org.jgrapht.ext.version>
         <org.assertj.core.version>3.9.0</org.assertj.core.version>
         <commons-codec.version>1.11</commons-codec.version>
+        <cobertura-maven-plugin.version>2.7</cobertura-maven-plugin.version>
     </properties>
 
 </project>

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

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

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

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

animal-sniffer-mvn-plugin/pom.xml

@@ -3,9 +3,9 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
     <artifactId>animal-sniffer-mvn-plugin</artifactId>
-    <packaging>jar</packaging>
     <version>1.0-SNAPSHOT</version>
     <name>animal-sniffer-mvn-plugin</name>
+    <packaging>jar</packaging>
     <url>http://maven.apache.org</url>
 
     <parent>