resolve conflict

.gitignore

@@ -33,3 +33,11 @@ spring-openid/src/main/resources/application.properties
 spring-security-openid/src/main/resources/application.properties
 
 spring-all/*.log
+
+*.jar
+
+SpringDataInjectionDemo/.mvn/wrapper/maven-wrapper.properties
+
+spring-call-getters-using-reflection/.mvn/wrapper/maven-wrapper.properties
+
+spring-check-if-a-property-is-null/.mvn/wrapper/maven-wrapper.properties

algorithms/README.md

@@ -6,3 +6,5 @@
 - [Validating Input With Finite Automata in Java](http://www.baeldung.com/finite-automata-java)
 - [Introduction to Jenetics Library](http://www.baeldung.com/jenetics)
 - [Check If a Number Is Prime in Java](http://www.baeldung.com/java-prime-numbers)
+- [Example of Hill Climbing Algorithm](http://www.baeldung.com/java-hill-climbing-algorithm)
+- [Monte Carlo Tree Search for Tic-Tac-Toe Game](http://www.baeldung.com/java-monte-carlo-tree-search)

algorithms/src/main/java/com/baeldung/algorithms/minimax/GameOfBones.java

@@ -0,0 +1,14 @@
+package com.baeldung.algorithms.minimax;
+
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+class GameOfBones {
+    static List<Integer> getPossibleStates(int noOfBonesInHeap) {
+        return IntStream.rangeClosed(1, 3).boxed()
+          .map(i -> noOfBonesInHeap - i)
+          .filter(newHeapCount -> newHeapCount >= 0)
+          .collect(Collectors.toList());
+    }
+}

algorithms/src/main/java/com/baeldung/algorithms/minimax/MiniMax.java

@@ -0,0 +1,60 @@
+package com.baeldung.algorithms.minimax;
+
+import java.util.Comparator;
+import java.util.List;
+import java.util.NoSuchElementException;
+
+public class MiniMax {
+    private Tree tree;
+
+    public Tree getTree() {
+        return tree;
+    }
+
+    public void constructTree(int noOfBones) {
+        tree = new Tree();
+        Node root = new Node(noOfBones, true);
+        tree.setRoot(root);
+        constructTree(root);
+    }
+
+    private void constructTree(Node parentNode) {
+        List<Integer> listofPossibleHeaps = GameOfBones.getPossibleStates(parentNode.getNoOfBones());
+        boolean isChildMaxPlayer = !parentNode.isMaxPlayer();
+        listofPossibleHeaps.forEach(n -> {
+            Node newNode = new Node(n, isChildMaxPlayer);
+            parentNode.addChild(newNode);
+            if (newNode.getNoOfBones() > 0) {
+                constructTree(newNode);
+            }
+        });
+    }
+
+    public boolean checkWin() {
+        Node root = tree.getRoot();
+        checkWin(root);
+        return root.getScore() == 1;
+    }
+
+    private void checkWin(Node node) {
+        List<Node> children = node.getChildren();
+        boolean isMaxPlayer = node.isMaxPlayer();
+        children.forEach(child -> {
+            if (child.getNoOfBones() == 0) {
+                child.setScore(isMaxPlayer ? 1 : -1);
+            } else {
+                checkWin(child);
+            }
+        });
+        Node bestChild = findBestChild(isMaxPlayer, children);
+        node.setScore(bestChild.getScore());
+    }
+
+    private Node findBestChild(boolean isMaxPlayer, List<Node> children) {
+        Comparator<Node> byScoreComparator = Comparator.comparing(Node::getScore);
+
+        return children.stream()
+          .max(isMaxPlayer ? byScoreComparator : byScoreComparator.reversed())
+          .orElseThrow(NoSuchElementException::new);
+    }
+}

algorithms/src/main/java/com/baeldung/algorithms/minimax/Node.java

@@ -0,0 +1,42 @@
+package com.baeldung.algorithms.minimax;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Node {
+    private int noOfBones;
+    private boolean isMaxPlayer;
+    private int score;
+    private List<Node> children;
+
+    public Node(int noOfBones, boolean isMaxPlayer) {
+        this.noOfBones = noOfBones;
+        this.isMaxPlayer = isMaxPlayer;
+        children = new ArrayList<>();
+    }
+
+    int getNoOfBones() {
+        return noOfBones;
+    }
+
+    boolean isMaxPlayer() {
+        return isMaxPlayer;
+    }
+
+    int getScore() {
+        return score;
+    }
+
+    void setScore(int score) {
+        this.score = score;
+    }
+
+    List<Node> getChildren() {
+        return children;
+    }
+
+    void addChild(Node newNode) {
+        children.add(newNode);
+    }
+
+}

algorithms/src/main/java/com/baeldung/algorithms/minimax/Tree.java

@@ -0,0 +1,16 @@
+package com.baeldung.algorithms.minimax;
+
+public class Tree {
+    private Node root;
+
+    Tree() {
+    }
+
+    Node getRoot() {
+        return root;
+    }
+
+    void setRoot(Node root) {
+        this.root = root;
+    }
+}

algorithms/src/test/java/algorithms/MCTSTest.java

@@ -0,0 +1,92 @@
+package algorithms;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.util.List;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.baeldung.algorithms.mcts.montecarlo.MonteCarloTreeSearch;
+import com.baeldung.algorithms.mcts.montecarlo.State;
+import com.baeldung.algorithms.mcts.montecarlo.UCT;
+import com.baeldung.algorithms.mcts.tictactoe.Board;
+import com.baeldung.algorithms.mcts.tictactoe.Position;
+import com.baeldung.algorithms.mcts.tree.Tree;
+
+public class MCTSTest {
+    Tree gameTree;
+    MonteCarloTreeSearch mcts;
+
+    @Before
+    public void initGameTree() {
+        gameTree = new Tree();
+        mcts = new MonteCarloTreeSearch();
+    }
+
+    @Test
+    public void givenStats_whenGetUCTForNode_thenUCTMatchesWithManualData() {
+        double uctValue = 15.79;
+        assertEquals(UCT.uctValue(600, 300, 20), uctValue, 0.01);
+    }
+
+    @Test
+    public void giveninitBoardState_whenGetAllPossibleStates_thenNonEmptyList() {
+        State initState = gameTree.getRoot().getState();
+        List<State> possibleStates = initState.getAllPossibleStates();
+        assertTrue(possibleStates.size() > 0);
+    }
+
+    @Test
+    public void givenEmptyBoard_whenPerformMove_thenLessAvailablePossitions() {
+        Board board = new Board();
+        int initAvailablePositions = board.getEmptyPositions().size();
+        board.performMove(Board.P1, new Position(1, 1));
+        int availablePositions = board.getEmptyPositions().size();
+        assertTrue(initAvailablePositions > availablePositions);
+    }
+
+    @Test
+    public void givenEmptyBoard_whenSimulateInterAIPlay_thenGameDraw() {
+        Board board = new Board();
+
+        int player = Board.P1;
+        int totalMoves = Board.DEFAULT_BOARD_SIZE * Board.DEFAULT_BOARD_SIZE;
+        for (int i = 0; i < totalMoves; i++) {
+            board = mcts.findNextMove(board, player);
+            if (board.checkStatus() != -1) {
+                break;
+            }
+            player = 3 - player;
+        }
+        int winStatus = board.checkStatus();
+        assertEquals(winStatus, Board.DRAW);
+    }
+
+    @Test
+    public void givenEmptyBoard_whenLevel1VsLevel3_thenLevel3WinsOrDraw() {
+        Board board = new Board();
+        MonteCarloTreeSearch mcts1 = new MonteCarloTreeSearch();
+        mcts1.setLevel(1);
+        MonteCarloTreeSearch mcts3 = new MonteCarloTreeSearch();
+        mcts3.setLevel(3);
+
+        int player = Board.P1;
+        int totalMoves = Board.DEFAULT_BOARD_SIZE * Board.DEFAULT_BOARD_SIZE;
+        for (int i = 0; i < totalMoves; i++) {
+            if (player == Board.P1)
+                board = mcts3.findNextMove(board, player);
+            else
+                board = mcts1.findNextMove(board, player);
+
+            if (board.checkStatus() != -1) {
+                break;
+            }
+            player = 3 - player;
+        }
+        int winStatus = board.checkStatus();
+        assertTrue(winStatus == Board.DRAW || winStatus == Board.P1);
+    }
+
+}

algorithms/src/test/java/algorithms/minimax/MinimaxTest.java

@@ -0,0 +1,36 @@
+package algorithms.minimax;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+import com.baeldung.algorithms.minimax.MiniMax;
+import com.baeldung.algorithms.minimax.Tree;
+
+public class MinimaxTest {
+    private Tree gameTree;
+    private MiniMax miniMax;
+
+    @Before
+    public void initMiniMaxUtility() {
+        miniMax = new MiniMax();
+    }
+
+    @Test
+    public void givenMiniMax_whenConstructTree_thenNotNullTree() {
+        assertNull(gameTree);
+        miniMax.constructTree(6);
+        gameTree = miniMax.getTree();
+        assertNotNull(gameTree);
+    }
+
+    @Test
+    public void givenMiniMax_whenCheckWin_thenComputeOptimal() {
+        miniMax.constructTree(6);
+        boolean result = miniMax.checkWin();
+        assertTrue(result);
+        miniMax.constructTree(8);
+        result = miniMax.checkWin();
+        assertFalse(result);
+    }
+}

aws/pom.xml

@@ -18,9 +18,41 @@
         <aws-lambda-java-events.version>1.3.0</aws-lambda-java-events.version>
         <aws-lambda-java-core.version>1.1.0</aws-lambda-java-core.version>
         <gson.version>2.8.0</gson.version>
+        <aws-java-sdk.version>1.11.154</aws-java-sdk.version>
+        <junit.version>4.12</junit.version>
+        <mockito-core.version>2.8.9</mockito-core.version>
+        <assertj-core.version>3.8.0</assertj-core.version>
     </properties>
 
     <dependencies>
+    
+        <dependency>
+            <groupId>com.amazonaws</groupId>
+            <artifactId>aws-java-sdk</artifactId>
+            <version>${aws-java-sdk.version}</version>
+        </dependency>
+        
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit.version}</version>
+            <scope>test</scope>
+        </dependency>
+        
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>${mockito-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+        
+        <dependency>
+            <groupId>org.assertj</groupId>
+            <artifactId>assertj-core</artifactId>
+            <version>${assertj-core.version}</version>
+            <scope>test</scope>
+        </dependency>
+    
         <dependency>
             <groupId>com.amazonaws</groupId>
             <artifactId>aws-lambda-java-core</artifactId>

aws/src/main/java/com/baeldung/s3/AWSS3Service.java

@@ -0,0 +1,87 @@
+package com.baeldung.s3;
+
+import java.io.File;
+import java.util.List;
+
+import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.AmazonS3Client;
+import com.amazonaws.services.s3.model.Bucket;
+import com.amazonaws.services.s3.model.CopyObjectResult;
+import com.amazonaws.services.s3.model.DeleteObjectsRequest;
+import com.amazonaws.services.s3.model.DeleteObjectsResult;
+import com.amazonaws.services.s3.model.ObjectListing;
+import com.amazonaws.services.s3.model.PutObjectResult;
+import com.amazonaws.services.s3.model.S3Object;
+
+public class AWSS3Service {
+    private final AmazonS3 s3client;
+
+    public AWSS3Service() { 
+        this(new AmazonS3Client() {
+        }); 
+    } 
+    
+    public AWSS3Service(AmazonS3 s3client) {
+        this.s3client = s3client;
+    }
+    
+    //is bucket exist?
+    public boolean doesBucketExist(String bucketName) { 
+        return s3client.doesBucketExist(bucketName); 
+    } 
+    
+    //create a bucket
+    public Bucket createBucket(String bucketName) { 
+        return s3client.createBucket(bucketName); 
+    } 
+
+    //list all buckets
+    public List<Bucket> listBuckets() { 
+        return s3client.listBuckets(); 
+    }
+
+    //delete a bucket
+    public void deleteBucket(String bucketName) { 
+        s3client.deleteBucket(bucketName); 
+    }  
+    
+    //uploading object
+    public PutObjectResult putObject(String bucketName, String key, File file) {
+        return s3client.putObject(bucketName, key, file);
+    }
+    
+    //listing objects
+    public ObjectListing listObjects(String bucketName) {
+        return s3client.listObjects(bucketName);
+    }
+    
+    //get an object
+    public S3Object getObject(String bucketName, String objectKey) {
+        return s3client.getObject(bucketName, objectKey);
+    } 
+    
+    //copying an object
+    public CopyObjectResult copyObject(
+      String sourceBucketName,
+      String sourceKey,
+      String destinationBucketName,
+      String destinationKey
+    ) {
+        return s3client.copyObject(
+          sourceBucketName, 
+          sourceKey, 
+          destinationBucketName, 
+          destinationKey
+        );
+    }
+    
+    //deleting an object
+    public void deleteObject(String bucketName, String objectKey) {
+        s3client.deleteObject(bucketName, objectKey);
+    }
+    
+    //deleting multiple Objects
+    public DeleteObjectsResult deleteObjects(DeleteObjectsRequest delObjReq) {
+        return s3client.deleteObjects(delObjReq);
+    }
+}

aws/src/main/java/com/baeldung/s3/S3Application.java

@@ -0,0 +1,108 @@
+package com.baeldung.s3;
+
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+
+import com.amazonaws.auth.AWSCredentials;
+import com.amazonaws.auth.AWSStaticCredentialsProvider;
+import com.amazonaws.auth.BasicAWSCredentials;
+import com.amazonaws.regions.Regions;
+import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.AmazonS3ClientBuilder;
+import com.amazonaws.services.s3.model.Bucket;
+import com.amazonaws.services.s3.model.DeleteObjectsRequest;
+import com.amazonaws.services.s3.model.ObjectListing;
+import com.amazonaws.services.s3.model.S3Object;
+import com.amazonaws.services.s3.model.S3ObjectInputStream;
+import com.amazonaws.services.s3.model.S3ObjectSummary;
+
+public class S3Application {
+
+    private static final AWSCredentials credentials;
+    private static String bucketName;  
+
+    static {
+        //put your accesskey and secretkey here
+        credentials = new BasicAWSCredentials(
+          "<AWS accesskey>", 
+          "<AWS secretkey>"
+        );
+    }  
+    
+    public static void main(String[] args) throws IOException {
+        //set-up the client
+        AmazonS3 s3client = AmazonS3ClientBuilder
+          .standard()
+          .withCredentials(new AWSStaticCredentialsProvider(credentials))
+          .withRegion(Regions.US_EAST_2)
+          .build();
+        
+        AWSS3Service awsService = new AWSS3Service(s3client);
+
+        bucketName = "baeldung-bucket";
+
+        //creating a bucket
+        if(awsService.doesBucketExist(bucketName)) {
+            System.out.println("Bucket name is not available."
+              + " Try again with a different Bucket name.");
+            return;
+        }
+        awsService.createBucket(bucketName);
+        
+        //list all the buckets
+        for(Bucket s : awsService.listBuckets() ) {
+            System.out.println(s.getName());
+        }
+        
+        //deleting bucket
+        awsService.deleteBucket("baeldung-bucket-test2");
+        
+        //uploading object
+        awsService.putObject(
+          bucketName, 
+          "Document/hello.txt",
+          new File("/Users/user/Document/hello.txt")
+        );
+
+        //listing objects
+        ObjectListing objectListing = awsService.listObjects(bucketName);
+        for(S3ObjectSummary os : objectListing.getObjectSummaries()) {
+            System.out.println(os.getKey());
+        }
+
+        //downloading an object
+        S3Object s3object = awsService.getObject(bucketName, "Document/hello.txt");
+        S3ObjectInputStream inputStream = s3object.getObjectContent();
+        FileOutputStream fos = new FileOutputStream(new File("/Users/user/Desktop/hello.txt"));
+
+        int read = 0;
+        byte[] bytes = new byte[1024];
+        while ((read = inputStream.read(bytes)) != -1) {
+            fos.write(bytes, 0, read);
+        }
+        inputStream.close();
+        fos.close();
+        
+        //copying an object
+        awsService.copyObject(
+          "baeldung-bucket", 
+          "picture/pic.png", 
+          "baeldung-bucket2", 
+          "Document/picture.png"
+        );
+        
+        //deleting an object
+        awsService.deleteObject(bucketName, "Document/hello.txt");
+
+        //deleting multiple objects
+        String objkeyArr[] = {
+          "Document/hello2.txt", 
+          "Document/picture.png"
+        };
+        
+        DeleteObjectsRequest delObjReq = new DeleteObjectsRequest("baeldung-bucket")
+          .withKeys(objkeyArr);
+        awsService.deleteObjects(delObjReq);
+    }
+}

aws/src/test/java/com/baeldung/s3/AWSS3ServiceIntegrationTest.java

@@ -0,0 +1,113 @@
+package com.baeldung.s3;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import java.io.File;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import com.amazonaws.services.s3.AmazonS3;
+import com.amazonaws.services.s3.model.CopyObjectResult;
+import com.amazonaws.services.s3.model.DeleteObjectsRequest;
+import com.amazonaws.services.s3.model.DeleteObjectsResult;
+import com.amazonaws.services.s3.model.PutObjectResult; 
+
+public class AWSS3ServiceIntegrationTest {
+
+    private static final String BUCKET_NAME = "bucket_name"; 
+    private static final String KEY_NAME = "key_name"; 
+    private static final String BUCKET_NAME2 = "bucket_name2"; 
+    private static final String KEY_NAME2 = "key_name2"; 
+ 
+    private AmazonS3 s3; 
+    private AWSS3Service service; 
+ 
+    @Before 
+    public void setUp() { 
+        s3 = mock(AmazonS3.class); 
+        service = new AWSS3Service(s3); 
+    } 
+ 
+    @Test 
+    public void whenInitializingAWSS3Service_thenNotNull() { 
+        assertThat(new AWSS3Service()).isNotNull(); 
+    } 
+    
+    @Test 
+    public void whenVerifyingIfS3BucketExist_thenCorrect() { 
+        service.doesBucketExist(BUCKET_NAME); 
+        verify(s3).doesBucketExist(BUCKET_NAME); 
+    } 
+ 
+    @Test 
+    public void whenVerifyingCreationOfS3Bucket_thenCorrect() { 
+        service.createBucket(BUCKET_NAME); 
+        verify(s3).createBucket(BUCKET_NAME); 
+    } 
+ 
+    @Test 
+    public void whenVerifyingListBuckets_thenCorrect() { 
+        service.listBuckets(); 
+        verify(s3).listBuckets(); 
+    } 
+
+    @Test 
+    public void whenDeletingBucket_thenCorrect() { 
+        service.deleteBucket(BUCKET_NAME); 
+        verify(s3).deleteBucket(BUCKET_NAME); 
+    } 
+    
+    @Test 
+    public void whenVerifyingPutObject_thenCorrect() { 
+        File file = mock(File.class); 
+        PutObjectResult result = mock(PutObjectResult.class); 
+        when(s3.putObject(anyString(), anyString(), (File) any())).thenReturn(result); 
+ 
+        assertThat(service.putObject(BUCKET_NAME, KEY_NAME, file)).isEqualTo(result); 
+        verify(s3).putObject(BUCKET_NAME, KEY_NAME, file); 
+    }
+    
+    @Test 
+    public void whenVerifyingListObjects_thenCorrect() { 
+        service.listObjects(BUCKET_NAME); 
+        verify(s3).listObjects(BUCKET_NAME); 
+    } 
+    
+    @Test 
+    public void whenVerifyingGetObject_thenCorrect() { 
+        service.getObject(BUCKET_NAME, KEY_NAME); 
+        verify(s3).getObject(BUCKET_NAME, KEY_NAME); 
+    } 
+    
+    @Test 
+    public void whenVerifyingCopyObject_thenCorrect() { 
+        CopyObjectResult result = mock(CopyObjectResult.class); 
+        when(s3.copyObject(anyString(), anyString(), anyString(), anyString())).thenReturn(result); 
+ 
+        assertThat(service.copyObject(BUCKET_NAME, KEY_NAME, BUCKET_NAME2, KEY_NAME2)).isEqualTo(result); 
+        verify(s3).copyObject(BUCKET_NAME, KEY_NAME, BUCKET_NAME2, KEY_NAME2);
+    } 
+    
+    @Test 
+    public void whenVerifyingDeleteObject_thenCorrect() { 
+        service.deleteObject(BUCKET_NAME, KEY_NAME); 
+        verify(s3).deleteObject(BUCKET_NAME, KEY_NAME); 
+    }
+    
+    @Test 
+    public void whenVerifyingDeleteObjects_thenCorrect() { 
+        DeleteObjectsRequest request = mock(DeleteObjectsRequest.class);
+        DeleteObjectsResult result = mock(DeleteObjectsResult.class);
+        when(s3.deleteObjects((DeleteObjectsRequest)any())).thenReturn(result); 
+        
+        assertThat(service.deleteObjects(request)).isEqualTo(result);
+        verify(s3).deleteObjects(request); 
+    }
+    
+}

core-java-9/README.md

@@ -13,3 +13,6 @@
 - [Java 9 Process API Improvements](http://www.baeldung.com/java-9-process-api)
 - [Introduction to Java 9 StackWalking API](http://www.baeldung.com/java-9-stackwalking-api)
 - [Introduction to Project Jigsaw](http://www.baeldung.com/project-jigsaw-java-modularity)
+- [Java 9 Optional API Additions](http://www.baeldung.com/java-9-optional)
+- [Java 9 Reactive Streams](http://www.baeldung.com/java-9-reactive-streams)
+- [How to Get All Dates Between Two Dates?](http://www.baeldung.com/java-between-dates)

core-java/README.md

@@ -113,6 +113,16 @@
 - [Difference Between Wait and Sleep in Java](http://www.baeldung.com/java-wait-and-sleep)
 - [LongAdder and LongAccumulator in Java](http://www.baeldung.com/java-longadder-and-longaccumulator)
 - [Using Java MappedByteBuffer](http://www.baeldung.com/java-mapped-byte-buffer)
+- [The Dining Philosophers Problem in Java](http://www.baeldung.com/java-dining-philoshophers)
+- [The Difference Between map() and flatMap()](http://www.baeldung.com/java-difference-map-and-flatmap)
+- [How to Round a Number to N Decimal Places in Java](http://www.baeldung.com/java-round-decimal-number)
+- [Changing Annotation Parameters At Runtime](http://www.baeldung.com/java-reflection-change-annotation-params)
+- [How to Find all Getters Returning Null](http://www.baeldung.com/java-getters-returning-null)
+- [Converting String to Stream of chars](http://www.baeldung.com/java-string-to-stream)
+- [Changing the Order in a Sum Operation Can Produce Different Results?](http://www.baeldung.com/java-floating-point-sum-order)
+- [How to Get a Name of a Method Being Executed?](http://www.baeldung.com/java-name-of-executing-method)
+- [Iterate over a Map in Java](http://www.baeldung.com/java-iterate-map)
+- [CyclicBarrier in Java](http://www.baeldung.com/java-cyclic-barrier)
 - [Dynamic Proxies in Java](http://www.baeldung.com/java-dynamic-proxies)
 - [How to Copy an Array in Java](http://www.baeldung.com/java-array-copy)
 - [Introduction to JDBC](http://www.baeldung.com/java-jdbc)

core-java/src/main/java/com/baeldung/deserialization/AppleProduct.java

@@ -0,0 +1,26 @@
+package com.baeldung.deserialization;
+
+import java.io.Serializable;
+
+public class AppleProduct implements Serializable {
+
+     private static final long serialVersionUID = 1234567L; // user-defined (i.e. not default or generated)
+//    private static final long serialVersionUID = 7654321L; // user-defined (i.e. not default or generated)
+
+    public String headphonePort;
+    public String thunderboltPort;
+    public String lighteningPort;
+
+    public String getHeadphonePort() {
+        return headphonePort;
+    }
+
+    public String getThunderboltPort() {
+        return thunderboltPort;
+    }
+
+    public static long getSerialVersionUID() {
+        return serialVersionUID;
+    }
+
+}

core-java/src/main/java/com/baeldung/deserialization/DeserializationUtility.java

@@ -0,0 +1,27 @@
+package com.baeldung.deserialization;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.util.Base64;
+
+public class DeserializationUtility {
+
+    public static void main(String[] args) throws ClassNotFoundException, IOException {
+
+        String serializedObj = "rO0ABXNyACljb20uYmFlbGR1bmcuZGVzZXJpYWxpemF0aW9uLkFwcGxlUHJvZHVjdAAAAAAAEtaHAgADTAANaGVhZHBob25lUG9ydHQAEkxqYXZhL2xhbmcvU3RyaW5nO0wADmxpZ2h0ZW5pbmdQb3J0cQB+AAFMAA90aHVuZGVyYm9sdFBvcnRxAH4AAXhwdAARaGVhZHBob25lUG9ydDIwMjBwdAATdGh1bmRlcmJvbHRQb3J0MjAyMA==";
+        System.out.println("Deserializing AppleProduct...");
+        AppleProduct deserializedObj = (AppleProduct) deSerializeObjectFromString(serializedObj);
+        System.out.println("Headphone port of AppleProduct:" + deserializedObj.getHeadphonePort());
+        System.out.println("Thunderbolt port of AppleProduct:" + deserializedObj.getThunderboltPort());
+    }
+
+    public static Object deSerializeObjectFromString(String s) throws IOException, ClassNotFoundException {
+        byte[] data = Base64.getDecoder().decode(s);
+        ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(data));
+        Object o = ois.readObject();
+        ois.close();
+        return o;
+    }
+
+}

core-java/src/main/java/com/baeldung/deserialization/SerializationUtility.java

@@ -0,0 +1,30 @@
+package com.baeldung.deserialization;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
+import java.util.Base64;
+
+public class SerializationUtility {
+
+    public static void main(String[] args) throws ClassNotFoundException, IOException {
+
+        AppleProduct macBook = new AppleProduct();
+        macBook.headphonePort = "headphonePort2020";
+        macBook.thunderboltPort = "thunderboltPort2020";
+
+        String serializedObj = serializeObjectToString(macBook);
+        System.out.println("Serialized AppleProduct object to string:");
+        System.out.println(serializedObj);
+    }
+
+    public static String serializeObjectToString(Serializable o) throws IOException {
+        ByteArrayOutputStream baos = new ByteArrayOutputStream();
+        ObjectOutputStream oos = new ObjectOutputStream(baos);
+        oos.writeObject(o);
+        oos.close();
+        return Base64.getEncoder().encodeToString(baos.toByteArray());
+    }
+
+}

core-java/src/main/java/com/baeldung/javanetworking/uriurl/URIDemo.java

@@ -0,0 +1,91 @@
+package com.baeldung.javanetworking.uriurl;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class URIDemo {
+    private final Logger logger = LoggerFactory.getLogger(URIDemo.class);
+
+    String URISTRING = "https://wordpress.org:443/support/topic/page-jumps-within-wordpress/?replies=3#post-2278484";
+    // parsed locator
+    String URISCHEME = "https";
+    String URISCHEMESPECIFIC;
+    String URIHOST = "wordpress.org";
+    String URIAUTHORITY = "wordpress.org:443";
+
+    String URIPATH = "/support/topic/page-jumps-within-wordpress/";
+    int URIPORT = 443;
+    String URIQUERY = "replies=3";
+    String URIFRAGMENT = "post-2278484";
+    String URIUSERINFO;
+    String URICOMPOUND = URISCHEME + "://" + URIHOST + ":" + URIPORT + URIPATH + "?" + URIQUERY + "#" + URIFRAGMENT;
+
+    URI uri;
+    URL url;
+    BufferedReader in = null;
+    String URIContent = "";
+
+    private String getParsedPieces(URI uri) {
+        logger.info("*** List of parsed pieces ***");
+        URISCHEME = uri.getScheme();
+        logger.info("URISCHEME: " + URISCHEME);
+        URISCHEMESPECIFIC = uri.getSchemeSpecificPart();
+        logger.info("URISCHEMESPECIFIC: " + URISCHEMESPECIFIC);
+        URIHOST = uri.getHost();
+        URIAUTHORITY = uri.getAuthority();
+        logger.info("URIAUTHORITY: " + URIAUTHORITY);
+        logger.info("URIHOST: " + URIHOST);
+        URIPATH = uri.getPath();
+        logger.info("URIPATH: " + URIPATH);
+        URIPORT = uri.getPort();
+        logger.info("URIPORT: " + URIPORT);
+        URIQUERY = uri.getQuery();
+        logger.info("URIQUERY: " + URIQUERY);
+        URIFRAGMENT = uri.getFragment();
+        logger.info("URIFRAGMENT: " + URIFRAGMENT);
+
+        try {
+            url = uri.toURL();
+        } catch (MalformedURLException e) {
+            logger.info("MalformedURLException thrown: " + e.getMessage());
+            e.printStackTrace();
+        } catch (IllegalArgumentException e) {
+            logger.info("IllegalArgumentException thrown: " + e.getMessage());
+            e.printStackTrace();
+        }
+        return url.toString();
+    }
+
+    public String testURIAsNew(String URIString) {
+        // creating URI object
+        try {
+            uri = new URI(URIString);
+        } catch (URISyntaxException e) {
+            logger.info("URISyntaxException thrown: " + e.getMessage());
+            e.printStackTrace();
+            throw new IllegalArgumentException();
+        }
+        return getParsedPieces(uri);
+    }
+
+    public String testURIAsCreate(String URIString) {
+        // creating URI object
+        uri = URI.create(URIString);
+        return getParsedPieces(uri);
+    }
+
+    public static void main(String[] args) throws Exception {
+        URIDemo demo = new URIDemo();
+        String contentCreate = demo.testURIAsCreate(demo.URICOMPOUND);
+        demo.logger.info(contentCreate);
+        String contentNew = demo.testURIAsNew(demo.URICOMPOUND);
+        demo.logger.info(contentNew);
+    }
+}

core-java/src/main/java/com/baeldung/javanetworking/uriurl/URLDemo.java

@@ -1,9 +1,10 @@
-package com.baeldung.javanetworking.url;
+package com.baeldung.javanetworking.uriurl;
 
 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.net.HttpURLConnection;
+import java.net.URI;
 import java.net.URL;
 import java.net.URLConnection;
 

core-java/src/main/java/com/baeldung/temporaladjuster/CustomTemporalAdjuster.java

@@ -0,0 +1,23 @@
+package com.baeldung.temporaladjuster;
+
+import java.time.DayOfWeek;
+import java.time.temporal.ChronoField;
+import java.time.temporal.ChronoUnit;
+import java.time.temporal.Temporal;
+import java.time.temporal.TemporalAdjuster;
+
+public class CustomTemporalAdjuster implements TemporalAdjuster {
+
+    @Override
+    public Temporal adjustInto(Temporal temporal) {
+        DayOfWeek dayOfWeek = DayOfWeek.of(temporal.get(ChronoField.DAY_OF_WEEK));
+        int daysToAdd;
+        if (dayOfWeek == DayOfWeek.FRIDAY)
+            daysToAdd = 3;
+        else if (dayOfWeek == DayOfWeek.SATURDAY)
+            daysToAdd = 2;
+        else
+            daysToAdd = 1;
+        return temporal.plus(daysToAdd, ChronoUnit.DAYS);
+    }
+}

core-java/src/test/java/com/baeldung/arraycopy/ArrayCopyUtilUnitTest.java

@@ -9,6 +9,8 @@ import org.junit.Test;
 
 import java.util.Arrays;
 
+import static org.junit.Assert.assertTrue;
+
 public class ArrayCopyUtilUnitTest {
     private static Employee[] employees;
     private static final int MAX = 2;
@@ -46,10 +48,10 @@ public class ArrayCopyUtilUnitTest {
         
         System.arraycopy(array, 2, copiedArray, 0, 3);
         
-        Assert.assertTrue(3 == copiedArray.length);
+        assertTrue(3 == copiedArray.length);
-        Assert.assertTrue(copiedArray[0] == array[2]);
+        assertTrue(copiedArray[0] == array[2]);
-        Assert.assertTrue(copiedArray[1] == array[3]);
+        assertTrue(copiedArray[1] == array[3]);
-        Assert.assertTrue(copiedArray[2] == array[4]);
+        assertTrue(copiedArray[2] == array[4]);
     }
 
     @Test
@@ -58,10 +60,10 @@ public class ArrayCopyUtilUnitTest {
         
         int[] copiedArray = Arrays.copyOfRange(array, 1, 4);
         
-        Assert.assertTrue(3 == copiedArray.length);
+        assertTrue(3 == copiedArray.length);
-        Assert.assertTrue(copiedArray[0] == array[1]);
+        assertTrue(copiedArray[0] == array[1]);
-        Assert.assertTrue(copiedArray[1] == array[2]);
+        assertTrue(copiedArray[1] == array[2]);
-        Assert.assertTrue(copiedArray[2] == array[3]);
+        assertTrue(copiedArray[2] == array[3]);
     }
 
     @Test
@@ -73,9 +75,9 @@ public class ArrayCopyUtilUnitTest {
         
         Assert.assertArrayEquals(copiedArray, array);
         array[0] = 9;
-        Assert.assertTrue(copiedArray[0] != array[0]);
+        assertTrue(copiedArray[0] != array[0]);
         copiedArray[1] = 12;
-        Assert.assertTrue(copiedArray[1] != array[1]);
+        assertTrue(copiedArray[1] != array[1]);
     }
 
     @Test
@@ -85,7 +87,7 @@ public class ArrayCopyUtilUnitTest {
         Assert.assertArrayEquals(copiedArray, employees);
         employees[0].setName(employees[0].getName()+"_Changed");
         //change in employees' element caused change in the copied array
-        Assert.assertTrue(copiedArray[0].getName().equals(employees[0].getName()));
+        assertTrue(copiedArray[0].getName().equals(employees[0].getName()));
     }
 
     @Test
@@ -96,9 +98,9 @@ public class ArrayCopyUtilUnitTest {
         
         Assert.assertArrayEquals(copiedArray, array);
         array[0] = 9;
-        Assert.assertTrue(copiedArray[0] != array[0]);
+        assertTrue(copiedArray[0] != array[0]);
         copiedArray[1] = 12;
-        Assert.assertTrue(copiedArray[1] != array[1]);
+        assertTrue(copiedArray[1] != array[1]);
     }
 
     @Test
@@ -108,7 +110,7 @@ public class ArrayCopyUtilUnitTest {
         Assert.assertArrayEquals(copiedArray, employees);;
         employees[0].setName(employees[0].getName()+"_Changed");
         //change in employees' element changed the copied array
-        Assert.assertTrue(copiedArray[0].getName().equals(employees[0].getName()));
+        assertTrue(copiedArray[0].getName().equals(employees[0].getName()));
     }
 
     @Test
@@ -138,7 +140,7 @@ public class ArrayCopyUtilUnitTest {
         Assert.assertArrayEquals(copiedArray, employees);
         employees[0].setName(employees[0].getName()+"_Changed");
         //change in employees' element didn't change in the copied array
-        Assert.assertTrue(copiedArray[0].getName().equals(employees[0].getName()));
+        assertTrue(copiedArray[0].getName().equals(employees[0].getName()));
     }
     
     @Test

core-java/src/test/java/com/baeldung/completablefuture/CompletableFutureLongRunningUnitTest.java

@@ -24,7 +24,7 @@ public class CompletableFutureLongRunningUnitTest {
         assertEquals("Hello", result);
     }
 
-    public Future<String> calculateAsync() throws InterruptedException {
+    private Future<String> calculateAsync() throws InterruptedException {
         CompletableFuture<String> completableFuture = new CompletableFuture<>();
 
         Executors.newCachedThreadPool().submit(() -> {
@@ -44,7 +44,7 @@ public class CompletableFutureLongRunningUnitTest {
         assertEquals("Hello", result);
     }
 
-    public Future<String> calculateAsyncWithCancellation() throws InterruptedException {
+    private Future<String> calculateAsyncWithCancellation() throws InterruptedException {
         CompletableFuture<String> completableFuture = new CompletableFuture<>();
 
         Executors.newCachedThreadPool().submit(() -> {

core-java/src/test/java/com/baeldung/concurrent/accumulator/LongAccumulatorUnitTest.java

@@ -24,8 +24,8 @@ public class LongAccumulatorUnitTest {
 
         //when
         Runnable accumulateAction = () -> IntStream
-                .rangeClosed(0, numberOfIncrements)
+          .rangeClosed(0, numberOfIncrements)
-                .forEach(accumulator::accumulate);
+          .forEach(accumulator::accumulate);
 
         for (int i = 0; i < numberOfThreads; i++) {
             executorService.execute(accumulateAction);

core-java/src/test/java/com/baeldung/concurrent/copyonwrite/CopyOnWriteArrayListUnitTest.java

@@ -17,7 +17,7 @@ public class CopyOnWriteArrayListUnitTest {
     public void givenCopyOnWriteList_whenIterateAndAddElementToUnderneathList_thenShouldNotChangeIterator() {
         //given
         final CopyOnWriteArrayList<Integer> numbers =
-                new CopyOnWriteArrayList<>(new Integer[]{1, 3, 5, 8});
+          new CopyOnWriteArrayList<>(new Integer[]{1, 3, 5, 8});
 
         //when
         Iterator<Integer> iterator = numbers.iterator();
@@ -42,7 +42,7 @@ public class CopyOnWriteArrayListUnitTest {
     public void givenCopyOnWriteList_whenIterateOverItAndTryToRemoveElement_thenShouldThrowException() {
         //given
         final CopyOnWriteArrayList<Integer> numbers =
-                new CopyOnWriteArrayList<>(new Integer[]{1, 3, 5, 8});
+          new CopyOnWriteArrayList<>(new Integer[]{1, 3, 5, 8});
 
         //when
         Iterator<Integer> iterator = numbers.iterator();

core-java/src/test/java/com/baeldung/concurrent/delayqueue/DelayQueueIntegrationTest.java

@@ -4,7 +4,11 @@ import org.junit.FixMethodOrder;
 import org.junit.Test;
 import org.junit.runners.MethodSorters;
 
-import java.util.concurrent.*;
+import java.util.concurrent.BlockingQueue;
+import java.util.concurrent.DelayQueue;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 
 import static junit.framework.TestCase.assertEquals;
 
@@ -19,7 +23,7 @@ public class DelayQueueIntegrationTest {
         int delayOfEachProducedMessageMilliseconds = 500;
         DelayQueueConsumer consumer = new DelayQueueConsumer(queue, numberOfElementsToProduce);
         DelayQueueProducer producer
-                = new DelayQueueProducer(queue, numberOfElementsToProduce, delayOfEachProducedMessageMilliseconds);
+          = new DelayQueueProducer(queue, numberOfElementsToProduce, delayOfEachProducedMessageMilliseconds);
 
         //when
         executor.submit(producer);
@@ -41,7 +45,7 @@ public class DelayQueueIntegrationTest {
         int delayOfEachProducedMessageMilliseconds = 10_000;
         DelayQueueConsumer consumer = new DelayQueueConsumer(queue, numberOfElementsToProduce);
         DelayQueueProducer producer
-                = new DelayQueueProducer(queue, numberOfElementsToProduce, delayOfEachProducedMessageMilliseconds);
+          = new DelayQueueProducer(queue, numberOfElementsToProduce, delayOfEachProducedMessageMilliseconds);
 
         //when
         executor.submit(producer);
@@ -63,7 +67,7 @@ public class DelayQueueIntegrationTest {
         int delayOfEachProducedMessageMilliseconds = -10_000;
         DelayQueueConsumer consumer = new DelayQueueConsumer(queue, numberOfElementsToProduce);
         DelayQueueProducer producer
-                = new DelayQueueProducer(queue, numberOfElementsToProduce, delayOfEachProducedMessageMilliseconds);
+          = new DelayQueueProducer(queue, numberOfElementsToProduce, delayOfEachProducedMessageMilliseconds);
 
         //when
         executor.submit(producer);

core-java/src/test/java/com/baeldung/concurrent/future/FactorialSquareCalculatorUnitTest.java

@@ -1,10 +1,10 @@
 package com.baeldung.concurrent.future;
 
-import static org.junit.Assert.assertEquals;
+import org.junit.Test;
 
 import java.util.concurrent.ForkJoinPool;
 
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
 
 public class FactorialSquareCalculatorUnitTest {
 

core-java/src/test/java/com/baeldung/concurrent/future/SquareCalculatorIntegrationTest.java

@@ -8,7 +8,12 @@ import org.junit.rules.TestName;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.concurrent.*;
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;

core-java/src/test/java/com/baeldung/concurrent/locks/SharedObjectWithLockManualTest.java

@@ -9,65 +9,65 @@ import static junit.framework.TestCase.assertEquals;
 
 public class SharedObjectWithLockManualTest {
 
-	@Test
+    @Test
-	public void whenLockAcquired_ThenLockedIsTrue() {
+    public void whenLockAcquired_ThenLockedIsTrue() {
-		final SharedObjectWithLock object = new SharedObjectWithLock();
+        final SharedObjectWithLock object = new SharedObjectWithLock();
 
-		final int threadCount = 2;
+        final int threadCount = 2;
-		final ExecutorService service = Executors.newFixedThreadPool(threadCount);
+        final ExecutorService service = Executors.newFixedThreadPool(threadCount);
 
-		executeThreads(object, threadCount, service);
+        executeThreads(object, threadCount, service);
 
-		assertEquals(true, object.isLocked());
+        assertEquals(true, object.isLocked());
 
-		service.shutdown();
+        service.shutdown();
-	}
+    }
 
-	@Test
+    @Test
-	public void whenLocked_ThenQueuedThread() {
+    public void whenLocked_ThenQueuedThread() {
-		final int threadCount = 4;
+        final int threadCount = 4;
-		final ExecutorService service = Executors.newFixedThreadPool(threadCount);
+        final ExecutorService service = Executors.newFixedThreadPool(threadCount);
-		final SharedObjectWithLock object = new SharedObjectWithLock();
+        final SharedObjectWithLock object = new SharedObjectWithLock();
 
-		executeThreads(object, threadCount, service);
+        executeThreads(object, threadCount, service);
 
-		assertEquals(object.hasQueuedThreads(), true);
+        assertEquals(object.hasQueuedThreads(), true);
 
-		service.shutdown();
+        service.shutdown();
 
-	}
+    }
 
-	public void whenTryLock_ThenQueuedThread() {
+    public void whenTryLock_ThenQueuedThread() {
-		final SharedObjectWithLock object = new SharedObjectWithLock();
+        final SharedObjectWithLock object = new SharedObjectWithLock();
 
-		final int threadCount = 2;
+        final int threadCount = 2;
-		final ExecutorService service = Executors.newFixedThreadPool(threadCount);
+        final ExecutorService service = Executors.newFixedThreadPool(threadCount);
 
-		executeThreads(object, threadCount, service);
+        executeThreads(object, threadCount, service);
 
-		assertEquals(true, object.isLocked());
+        assertEquals(true, object.isLocked());
 
-		service.shutdown();
+        service.shutdown();
-	}
+    }
 
-	@Test
+    @Test
-	public void whenGetCount_ThenCorrectCount() throws InterruptedException {
+    public void whenGetCount_ThenCorrectCount() throws InterruptedException {
-		final int threadCount = 4;
+        final int threadCount = 4;
-		final ExecutorService service = Executors.newFixedThreadPool(threadCount);
+        final ExecutorService service = Executors.newFixedThreadPool(threadCount);
-		final SharedObjectWithLock object = new SharedObjectWithLock();
+        final SharedObjectWithLock object = new SharedObjectWithLock();
 
-		executeThreads(object, threadCount, service);
+        executeThreads(object, threadCount, service);
-		Thread.sleep(1000);
+        Thread.sleep(1000);
-		assertEquals(object.getCounter(), 4);
+        assertEquals(object.getCounter(), 4);
 
-		service.shutdown();
+        service.shutdown();
 
-	}
+    }
 
-	private void executeThreads(SharedObjectWithLock object, int threadCount, ExecutorService service) {
+    private void executeThreads(SharedObjectWithLock object, int threadCount, ExecutorService service) {
-		for (int i = 0; i < threadCount; i++) {
+        for (int i = 0; i < threadCount; i++) {
-			service.execute(object::perform);
+            service.execute(object::perform);
-		}
+        }
-	}
+    }
 
 }

core-java/src/test/java/com/baeldung/concurrent/locks/SynchronizedHashMapWithRWLockManualTest.java

@@ -1,6 +1,5 @@
 package com.baeldung.concurrent.locks;
 
-import jdk.nashorn.internal.ir.annotations.Ignore;
 import org.junit.Test;
 
 import java.util.concurrent.ExecutorService;
@@ -10,49 +9,49 @@ import static junit.framework.TestCase.assertEquals;
 
 public class SynchronizedHashMapWithRWLockManualTest {
 
-	@Test
+    @Test
-	public void whenWriting_ThenNoReading() {
+    public void whenWriting_ThenNoReading() {
-		SynchronizedHashMapWithRWLock object = new SynchronizedHashMapWithRWLock();
+        SynchronizedHashMapWithRWLock object = new SynchronizedHashMapWithRWLock();
-		final int threadCount = 3;
+        final int threadCount = 3;
-		final ExecutorService service = Executors.newFixedThreadPool(threadCount);
+        final ExecutorService service = Executors.newFixedThreadPool(threadCount);
 
-		executeWriterThreads(object, threadCount, service);
+        executeWriterThreads(object, threadCount, service);
 
-		assertEquals(object.isReadLockAvailable(), false);
+        assertEquals(object.isReadLockAvailable(), false);
 
-		service.shutdown();
+        service.shutdown();
-	}
+    }
 
-	@Test
+    @Test
-	public void whenReading_ThenMultipleReadingAllowed() {
+    public void whenReading_ThenMultipleReadingAllowed() {
-		SynchronizedHashMapWithRWLock object = new SynchronizedHashMapWithRWLock();
+        SynchronizedHashMapWithRWLock object = new SynchronizedHashMapWithRWLock();
-		final int threadCount = 5;
+        final int threadCount = 5;
-		final ExecutorService service = Executors.newFixedThreadPool(threadCount);
+        final ExecutorService service = Executors.newFixedThreadPool(threadCount);
 
-		executeReaderThreads(object, threadCount, service);
+        executeReaderThreads(object, threadCount, service);
 
-		assertEquals(object.isReadLockAvailable(), true);
+        assertEquals(object.isReadLockAvailable(), true);
 
-		service.shutdown();
+        service.shutdown();
-	}
+    }
 
-	private void executeWriterThreads(SynchronizedHashMapWithRWLock object, int threadCount, ExecutorService service) {
+    private void executeWriterThreads(SynchronizedHashMapWithRWLock object, int threadCount, ExecutorService service) {
-		for (int i = 0; i < threadCount; i++) {
+        for (int i = 0; i < threadCount; i++) {
-			service.execute(() -> {
+            service.execute(() -> {
-				try {
+                try {
-					object.put("key" + threadCount, "value" + threadCount);
+                    object.put("key" + threadCount, "value" + threadCount);
-				} catch (InterruptedException e) {
+                } catch (InterruptedException e) {
-					e.printStackTrace();
+                    e.printStackTrace();
-				}
+                }
-			});
+            });
-		}
+        }
-	}
+    }
 
-	private void executeReaderThreads(SynchronizedHashMapWithRWLock object, int threadCount, ExecutorService service) {
+    private void executeReaderThreads(SynchronizedHashMapWithRWLock object, int threadCount, ExecutorService service) {
-		for (int i = 0; i < threadCount; i++)
+        for (int i = 0; i < threadCount; i++)
-			service.execute(() -> {
+            service.execute(() -> {
-				object.get("key" + threadCount);
+                object.get("key" + threadCount);
-			});
+            });
-	}
+    }
 
 }

core-java/src/test/java/com/baeldung/concurrent/priorityblockingqueue/PriorityBlockingQueueIntegrationTest.java

@@ -42,7 +42,7 @@ public class PriorityBlockingQueueIntegrationTest {
                 try {
                     Integer poll = queue.take();
                     LOG.debug("Polled: " + poll);
-                } catch (InterruptedException e) {
+                } catch (InterruptedException ignored) {
                 }
             }
         });

core-java/src/test/java/com/baeldung/concurrent/synchronize/BaeldungSychronizedBlockTest.java

@@ -1,13 +1,13 @@
 package com.baeldung.concurrent.synchronize;
 
-import static org.junit.Assert.assertEquals;
+import org.junit.Test;
 
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.IntStream;
 
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
 
 public class BaeldungSychronizedBlockTest {
 
@@ -17,7 +17,7 @@ public class BaeldungSychronizedBlockTest {
         BaeldungSynchronizedBlocks synchronizedBlocks = new BaeldungSynchronizedBlocks();
 
         IntStream.range(0, 1000)
-            .forEach(count -> service.submit(synchronizedBlocks::performSynchronisedTask));
+          .forEach(count -> service.submit(synchronizedBlocks::performSynchronisedTask));
         service.awaitTermination(100, TimeUnit.MILLISECONDS);
 
         assertEquals(1000, synchronizedBlocks.getCount());
@@ -28,7 +28,7 @@ public class BaeldungSychronizedBlockTest {
         ExecutorService service = Executors.newCachedThreadPool();
 
         IntStream.range(0, 1000)
-            .forEach(count -> service.submit(BaeldungSynchronizedBlocks::performStaticSyncTask));
+          .forEach(count -> service.submit(BaeldungSynchronizedBlocks::performStaticSyncTask));
         service.awaitTermination(100, TimeUnit.MILLISECONDS);
 
         assertEquals(1000, BaeldungSynchronizedBlocks.getStaticCount());

core-java/src/test/java/com/baeldung/concurrent/synchronize/BaeldungSynchronizeMethodsTest.java

@@ -1,14 +1,14 @@
 package com.baeldung.concurrent.synchronize;
 
-import static org.junit.Assert.assertEquals;
+import org.junit.Ignore;
+import org.junit.Test;
 
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.TimeUnit;
 import java.util.stream.IntStream;
 
-import org.junit.Ignore;
+import static org.junit.Assert.assertEquals;
-import org.junit.Test;
 
 public class BaeldungSynchronizeMethodsTest {
 
@@ -19,7 +19,7 @@ public class BaeldungSynchronizeMethodsTest {
         BaeldungSynchronizedMethods method = new BaeldungSynchronizedMethods();
 
         IntStream.range(0, 1000)
-            .forEach(count -> service.submit(method::calculate));
+          .forEach(count -> service.submit(method::calculate));
         service.awaitTermination(100, TimeUnit.MILLISECONDS);
 
         assertEquals(1000, method.getSum());
@@ -31,7 +31,7 @@ public class BaeldungSynchronizeMethodsTest {
         BaeldungSynchronizedMethods method = new BaeldungSynchronizedMethods();
 
         IntStream.range(0, 1000)
-            .forEach(count -> service.submit(method::synchronisedCalculate));
+          .forEach(count -> service.submit(method::synchronisedCalculate));
         service.awaitTermination(100, TimeUnit.MILLISECONDS);
 
         assertEquals(1000, method.getSyncSum());
@@ -42,7 +42,7 @@ public class BaeldungSynchronizeMethodsTest {
         ExecutorService service = Executors.newCachedThreadPool();
 
         IntStream.range(0, 1000)
-            .forEach(count -> service.submit(BaeldungSynchronizedMethods::syncStaticCalculate));
+          .forEach(count -> service.submit(BaeldungSynchronizedMethods::syncStaticCalculate));
         service.awaitTermination(100, TimeUnit.MILLISECONDS);
 
         assertEquals(1000, BaeldungSynchronizedMethods.staticSum);

core-java/src/test/java/com/baeldung/datetime/UseLocalDateTimeUnitTest.java

@@ -7,13 +7,15 @@ import java.time.Month;
 import org.junit.Assert;
 import org.junit.Test;
 
+import static org.junit.Assert.assertEquals;
+
 public class UseLocalDateTimeUnitTest {
 
     UseLocalDateTime useLocalDateTime = new UseLocalDateTime();
 
     @Test
     public void givenString_whenUsingParse_thenLocalDateTime() {
-        Assert.assertEquals(LocalDate.of(2016, Month.MAY, 10), useLocalDateTime.getLocalDateTimeUsingParseMethod("2016-05-10T06:30").toLocalDate());
+        assertEquals(LocalDate.of(2016, Month.MAY, 10), useLocalDateTime.getLocalDateTimeUsingParseMethod("2016-05-10T06:30").toLocalDate());
-        Assert.assertEquals(LocalTime.of(6, 30), useLocalDateTime.getLocalDateTimeUsingParseMethod("2016-05-10T06:30").toLocalTime());
+        assertEquals(LocalTime.of(6, 30), useLocalDateTime.getLocalDateTimeUsingParseMethod("2016-05-10T06:30").toLocalTime());
     }
 }

core-java/src/test/java/com/baeldung/datetime/UseLocalDateUnitTest.java

@@ -7,48 +7,50 @@ import java.time.LocalDateTime;
 import org.junit.Assert;
 import org.junit.Test;
 
+import static org.junit.Assert.assertEquals;
+
 public class UseLocalDateUnitTest {
 
     UseLocalDate useLocalDate = new UseLocalDate();
 
     @Test
     public void givenValues_whenUsingFactoryOf_thenLocalDate() {
-        Assert.assertEquals("2016-05-10", useLocalDate.getLocalDateUsingFactoryOfMethod(2016, 5, 10).toString());
+        assertEquals("2016-05-10", useLocalDate.getLocalDateUsingFactoryOfMethod(2016, 5, 10).toString());
     }
 
     @Test
     public void givenString_whenUsingParse_thenLocalDate() {
-        Assert.assertEquals("2016-05-10", useLocalDate.getLocalDateUsingParseMethod("2016-05-10").toString());
+        assertEquals("2016-05-10", useLocalDate.getLocalDateUsingParseMethod("2016-05-10").toString());
     }
 
     @Test
     public void whenUsingClock_thenLocalDate() {
-        Assert.assertEquals(LocalDate.now(), useLocalDate.getLocalDateFromClock());
+        assertEquals(LocalDate.now(), useLocalDate.getLocalDateFromClock());
     }
 
     @Test
     public void givenDate_whenUsingPlus_thenNextDay() {
-        Assert.assertEquals(LocalDate.now().plusDays(1), useLocalDate.getNextDay(LocalDate.now()));
+        assertEquals(LocalDate.now().plusDays(1), useLocalDate.getNextDay(LocalDate.now()));
     }
 
     @Test
     public void givenDate_whenUsingMinus_thenPreviousDay() {
-        Assert.assertEquals(LocalDate.now().minusDays(1), useLocalDate.getPreviousDay(LocalDate.now()));
+        assertEquals(LocalDate.now().minusDays(1), useLocalDate.getPreviousDay(LocalDate.now()));
     }
 
     @Test
     public void givenToday_whenUsingGetDayOfWeek_thenDayOfWeek() {
-        Assert.assertEquals(DayOfWeek.SUNDAY, useLocalDate.getDayOfWeek(LocalDate.parse("2016-05-22")));
+        assertEquals(DayOfWeek.SUNDAY, useLocalDate.getDayOfWeek(LocalDate.parse("2016-05-22")));
     }
 
     @Test
     public void givenToday_whenUsingWithTemporalAdjuster_thenFirstDayOfMonth() {
-        Assert.assertEquals(1, useLocalDate.getFirstDayOfMonth().getDayOfMonth());
+        assertEquals(1, useLocalDate.getFirstDayOfMonth().getDayOfMonth());
     }
 
     @Test
     public void givenLocalDate_whenUsingAtStartOfDay_thenReturnMidnight() {
-        Assert.assertEquals(LocalDateTime.parse("2016-05-22T00:00:00"), useLocalDate.getStartOfDay(LocalDate.parse("2016-05-22")));
+        assertEquals(LocalDateTime.parse("2016-05-22T00:00:00"), useLocalDate.getStartOfDay(LocalDate.parse("2016-05-22")));
     }
 
 }

core-java/src/test/java/com/baeldung/deserialization/DeserializationUnitTest.java

@@ -0,0 +1,67 @@
+package com.baeldung.deserialization;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
+
+import java.io.IOException;
+import java.io.InvalidClassException;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class DeserializationUnitTest {
+
+    private static final String serializedObj = "rO0ABXNyACljb20uYmFlbGR1bmcuZGVzZXJpYWxpemF0aW9uLkFwcGxlUHJvZHVjdAAAAAAAEtaHAgADTAANaGVhZHBob25lUG9ydHQAEkxqYXZhL2xhbmcvU3RyaW5nO0wADmxpZ2h0ZW5pbmdQb3J0cQB+AAFMAA90aHVuZGVyYm9sdFBvcnRxAH4AAXhwdAARaGVhZHBob25lUG9ydDIwMjBwdAATdGh1bmRlcmJvbHRQb3J0MjAyMA==";
+
+    private static long userDefinedSerialVersionUID = 1234567L;
+
+    /**
+     * Tests the deserialization of the original "AppleProduct" (no exceptions are thrown)
+     * @throws ClassNotFoundException
+     * @throws IOException
+     */
+    @Test
+    public void testDeserializeObj_compatible() throws IOException, ClassNotFoundException {
+
+        assertEquals(userDefinedSerialVersionUID, AppleProduct.getSerialVersionUID());
+        
+        AppleProduct macBook = new AppleProduct();
+        macBook.headphonePort = "headphonePort2020";
+        macBook.thunderboltPort = "thunderboltPort2020";
+        
+        // serializes the "AppleProduct" object
+        String serializedProduct = SerializationUtility.serializeObjectToString(macBook);
+
+        // deserializes the "AppleProduct" object
+        AppleProduct deserializedProduct = (AppleProduct) DeserializationUtility.deSerializeObjectFromString(serializedProduct);
+     
+        assertTrue(deserializedProduct.headphonePort.equalsIgnoreCase(macBook.headphonePort));
+        assertTrue(deserializedProduct.thunderboltPort.equalsIgnoreCase(macBook.thunderboltPort));
+    
+    }
+
+    /**
+     * Tests the deserialization of the modified (non-compatible) "AppleProduct".
+     * The test should result in an InvalidClassException being thrown.
+     * 
+     * Note: to run this test: 
+     *          1. Modify the value of the serialVersionUID identifier in AppleProduct.java
+     *          2. Remove the @Ignore annotation
+     *          3. Run the test individually (do not run the entire set of tests)
+     *          4. Revert the changes made in 1 & 2 (so that you're able to re-run the tests successfully)
+     *          
+     * @throws ClassNotFoundException
+     * @throws IOException
+     */
+    @Ignore
+    @Test(expected = InvalidClassException.class)
+    public void testDeserializeObj_incompatible() throws ClassNotFoundException, IOException {
+
+        assertNotEquals(userDefinedSerialVersionUID, AppleProduct.getSerialVersionUID());
+        
+        // attempts to deserialize the "AppleProduct" object
+        DeserializationUtility.deSerializeObjectFromString(serializedObj);
+    }
+
+}

core-java/src/test/java/com/baeldung/doublecolon/ComputerUtilsUnitTest.java

@@ -83,7 +83,7 @@ public class ComputerUtilsUnitTest {
 
         final TriFunction<Integer, String, Integer, MacbookPro> integerStringIntegerObjectTriFunction = MacbookPro::new;
         final MacbookPro macbookPro = integerStringIntegerObjectTriFunction.apply(2010, "black", 100);
-        Double initialValue = new Double(999.99);
+        Double initialValue = 999.99;
         final Double actualValue = macbookPro.calculateValue(initialValue);
         Assert.assertEquals(766.659, actualValue, 0.0);
     }

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

@@ -6,7 +6,12 @@ import org.hamcrest.Matchers;
 import org.junit.Assert;
 import org.junit.Test;
 
-import java.io.*;
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
 import java.net.URISyntaxException;
 import java.net.URL;
 import java.net.URLConnection;
@@ -14,6 +19,10 @@ import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.stream.Stream;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+
 public class FileOperationsManualTest {
 
     @Test
@@ -25,7 +34,7 @@ public class FileOperationsManualTest {
         InputStream inputStream = new FileInputStream(file);
         String data = readFromInputStream(inputStream);
 
-        Assert.assertEquals(expectedData, data.trim());
+        assertEquals(expectedData, data.trim());
     }
 
     @Test
@@ -36,7 +45,7 @@ public class FileOperationsManualTest {
         InputStream inputStream = clazz.getResourceAsStream("/fileTest.txt");
         String data = readFromInputStream(inputStream);
 
-        Assert.assertEquals(expectedData, data.trim());
+        assertEquals(expectedData, data.trim());
     }
 
     @Test
@@ -47,7 +56,7 @@ public class FileOperationsManualTest {
         InputStream inputStream = clazz.getResourceAsStream("/LICENSE.txt");
         String data = readFromInputStream(inputStream);
 
-        Assert.assertThat(data.trim(), CoreMatchers.containsString(expectedData));
+        assertThat(data.trim(), CoreMatchers.containsString(expectedData));
     }
 
     @Test
@@ -61,7 +70,7 @@ public class FileOperationsManualTest {
         InputStream inputStream = urlConnection.getInputStream();
         String data = readFromInputStream(inputStream);
 
-        Assert.assertThat(data.trim(), CoreMatchers.containsString(expectedData));
+        assertThat(data.trim(), CoreMatchers.containsString(expectedData));
     }
 
     @Test
@@ -72,7 +81,7 @@ public class FileOperationsManualTest {
         File file = new File(classLoader.getResource("fileTest.txt").getFile());
         String data = FileUtils.readFileToString(file);
 
-        Assert.assertEquals(expectedData, data.trim());
+        assertEquals(expectedData, data.trim());
     }
 
     @Test
@@ -84,7 +93,7 @@ public class FileOperationsManualTest {
         byte[] fileBytes = Files.readAllBytes(path);
         String data = new String(fileBytes);
 
-        Assert.assertEquals(expectedData, data.trim());
+        assertEquals(expectedData, data.trim());
     }
 
     @Test
@@ -98,7 +107,7 @@ public class FileOperationsManualTest {
         lines.forEach(line -> data.append(line).append("\n"));
         lines.close();
 
-        Assert.assertEquals(expectedData, data.toString().trim());
+        assertEquals(expectedData, data.toString().trim());
     }
 
     private String readFromInputStream(InputStream inputStream) throws IOException {

core-java/src/test/java/com/baeldung/filesystem/jndi/test/LookupFSJNDIIntegrationTest.java

@@ -1,15 +1,13 @@
 package com.baeldung.filesystem.jndi.test;
 
-import static org.junit.Assert.assertNotNull;
+import com.baeldung.filesystem.jndi.LookupFSJNDI;
-
+import org.junit.Test;
-import java.io.File;
 
 import javax.naming.InitialContext;
 import javax.naming.NamingException;
+import java.io.File;
 
-import org.junit.Test;
+import static org.junit.Assert.assertNotNull;
-
-import com.baeldung.filesystem.jndi.LookupFSJNDI;
 
 public class LookupFSJNDIIntegrationTest {
     LookupFSJNDI fsjndi;

core-java/src/test/java/com/baeldung/functionalinterface/FunctionalInterfaceUnitTest.java

@@ -25,7 +25,7 @@ public class FunctionalInterfaceUnitTest {
     @Test
     public void whenPassingLambdaToComputeIfAbsent_thenTheValueGetsComputedAndPutIntoMap() {
         Map<String, Integer> nameMap = new HashMap<>();
-        Integer value = nameMap.computeIfAbsent("John", s -> s.length());
+        Integer value = nameMap.computeIfAbsent("John", String::length);
 
         assertEquals(new Integer(4), nameMap.get("John"));
         assertEquals(new Integer(4), value);

core-java/src/test/java/com/baeldung/hashing/SHA256HashingUnitTest.java

@@ -2,7 +2,7 @@ package com.baeldung.hashing;
 
 import org.junit.Test;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
 
 public class SHA256HashingUnitTest {
 

core-java/src/test/java/com/baeldung/http/HttpRequestLiveTest.java

@@ -2,7 +2,6 @@ package com.baeldung.http;
 
 import org.apache.commons.lang.StringUtils;
 import org.junit.Test;
-import static org.junit.Assert.*;
 
 import java.io.BufferedReader;
 import java.io.DataOutputStream;
@@ -17,6 +16,9 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
 public class HttpRequestLiveTest {
 
     @Test
@@ -39,7 +41,7 @@ public class HttpRequestLiveTest {
         int status = con.getResponseCode();
         BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
         String inputLine;
-        StringBuffer content = new StringBuffer();
+        StringBuilder content = new StringBuilder();
         while ((inputLine = in.readLine()) != null) {
             content.append(inputLine);
         }
@@ -67,7 +69,7 @@ public class HttpRequestLiveTest {
         int status = con.getResponseCode();
         BufferedReader in = new BufferedReader(new InputStreamReader(con.getInputStream()));
         String inputLine;
-        StringBuffer content = new StringBuffer();
+        StringBuilder content = new StringBuilder();
         while ((inputLine = in.readLine()) != null) {
             content.append(inputLine);
         }

core-java/src/test/java/com/baeldung/javanetworking/uriurl/test/URIDemoTest.java

@@ -0,0 +1,65 @@
+package com.baeldung.javanetworking.uriurl.test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.net.URLConnection;
+
+import org.junit.BeforeClass;
+import org.junit.FixMethodOrder;
+import org.junit.Test;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.baeldung.javanetworking.uriurl.URLDemo;
+
+@FixMethodOrder
+public class URIDemoTest {
+    private final Logger log = LoggerFactory.getLogger(URIDemoTest.class);
+    String URISTRING = "https://wordpress.org:443/support/topic/page-jumps-within-wordpress/?replies=3#post-2278484";
+    // parsed locator
+    static String URISCHEME = "https";
+    String URISCHEMESPECIFIC;
+    static String URIHOST = "wordpress.org";
+    static String URIAUTHORITY = "wordpress.org:443";
+
+    static String URIPATH = "/support/topic/page-jumps-within-wordpress/";
+    int URIPORT = 443;
+    static int URIDEFAULTPORT = 443;
+    static String URIQUERY = "replies=3";
+    static String URIFRAGMENT = "post-2278484";
+    static String URICOMPOUND = URISCHEME + "://" + URIHOST + ":" + URIDEFAULTPORT + URIPATH + "?" + URIQUERY + "#" + URIFRAGMENT;
+
+    static URI uri;
+    URL url;
+    BufferedReader in = null;
+    String URIContent = "";
+
+    @BeforeClass
+    public static void givenEmplyURL_whenInitializeURL_thenSuccess() throws URISyntaxException {
+        uri = new URI(URICOMPOUND);
+    }
+
+    // check parsed URL
+    @Test
+    public void givenURI_whenURIIsParsed_thenSuccess() {
+        assertNotNull("URI is null", uri);
+        assertEquals("URI string is not equal", uri.toString(), URISTRING);
+        assertEquals("Scheme is not equal", uri.getScheme(), URISCHEME);
+        assertEquals("Authority is not equal", uri.getAuthority(), URIAUTHORITY);
+        assertEquals("Host string is not equal", uri.getHost(), URIHOST);
+        assertEquals("Path string is not equal", uri.getPath(), URIPATH);
+        assertEquals("Port number is not equal", uri.getPort(), URIPORT);
+        assertEquals("Query string is not equal", uri.getQuery(), URIQUERY);
+        assertEquals("Fragment string is not equal", uri.getFragment(), URIFRAGMENT);
+    }
+}

core-java/src/test/java/com/baeldung/javanetworking/uriurl/test/URLDemoTest.java

@@ -1,4 +1,4 @@
-package com.baeldung.javanetworking.url.test;
+package com.baeldung.javanetworking.uriurl.test;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
@@ -18,11 +18,11 @@ import org.junit.Test;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.baeldung.javanetworking.url.URLDemo;
+import com.baeldung.javanetworking.uriurl.URLDemo;
 
 @FixMethodOrder
 public class URLDemoTest {
-    private final Logger log = LoggerFactory.getLogger(URLDemo.class);
+    private final Logger log = LoggerFactory.getLogger(URLDemoTest.class);
     static String URLSTRING = "https://wordpress.org:443/support/topic/page-jumps-within-wordpress/?replies=3#post-2278484";
     // parsed locator
     static String URLPROTOCOL = "https";

core-java/src/test/java/com/baeldung/list/flattennestedlist/FlattenNestedListUnitTest.java

@@ -14,7 +14,7 @@ import org.hamcrest.collection.IsIterableContainingInOrder;
 import org.junit.Test;
 
 public class FlattenNestedListUnitTest {
-    List<List<String>> lol = asList(asList("one:one"), asList("two:one", "two:two", "two:three"), asList("three:one", "three:two", "three:three", "three:four"));
+    private List<List<String>> lol = asList(asList("one:one"), asList("two:one", "two:two", "two:three"), asList("three:one", "three:two", "three:three", "three:four"));
 
     @Test
     public void givenNestedList_thenFlattenImperatively() {
@@ -36,13 +36,13 @@ public class FlattenNestedListUnitTest {
         assertThat(ls, IsIterableContainingInOrder.contains("one:one", "two:one", "two:two", "two:three", "three:one", "three:two", "three:three", "three:four"));
     }
 
-    public <T> List<T> flattenListOfListsImperatively(List<List<T>> list) {
+    private <T> List<T> flattenListOfListsImperatively(List<List<T>> list) {
         List<T> ls = new ArrayList<>();
         list.forEach(ls::addAll);
         return ls;
     }
 
-    public <T> List<T> flattenListOfListsStream(List<List<T>> list) {
+    private <T> List<T> flattenListOfListsStream(List<List<T>> list) {
         return list.stream().flatMap(Collection::stream).collect(Collectors.toList());
     }
 }

core-java/src/test/java/com/baeldung/list/listoflist/ListOfListsUnitTest.java

@@ -1,18 +1,19 @@
 package com.baeldung.list.listoflist;
 
+import org.junit.Before;
+import org.junit.Test;
+
 import java.util.ArrayList;
 import java.util.List;
 
 import static org.junit.Assert.assertEquals;
-import org.junit.Before;
-import org.junit.Test;
 
 public class ListOfListsUnitTest {
 
-    private List<ArrayList<? extends Stationery>> listOfLists = new ArrayList<ArrayList<? extends Stationery>>();
+    private List<List<? extends Stationery>> listOfLists = new ArrayList<>();
-    private ArrayList<Pen> penList = new ArrayList<>();
+    private List<Pen> penList = new ArrayList<>();
-    private ArrayList<Pencil> pencilList = new ArrayList<>();
+    private List<Pencil> pencilList = new ArrayList<>();
-    private ArrayList<Rubber> rubberList = new ArrayList<>();
+    private List<Rubber> rubberList = new ArrayList<>();
 
     @SuppressWarnings("unchecked")
     @Before
@@ -29,11 +30,11 @@ public class ListOfListsUnitTest {
     @Test
     public void givenListOfLists_thenCheckNames() {
         assertEquals("Pen 1", ((Pen) listOfLists.get(0)
-            .get(0)).getName());
+          .get(0)).getName());
         assertEquals("Pencil 1", ((Pencil) listOfLists.get(1)
-            .get(0)).getName());
+          .get(0)).getName());
         assertEquals("Rubber 1", ((Rubber) listOfLists.get(2)
-            .get(0)).getName());
+          .get(0)).getName());
     }
 
     @SuppressWarnings("unchecked")
@@ -43,10 +44,10 @@ public class ListOfListsUnitTest {
         ((ArrayList<Pencil>) listOfLists.get(1)).remove(0);
         listOfLists.remove(1);
         assertEquals("Rubber 1", ((Rubber) listOfLists.get(1)
-            .get(0)).getName());
+          .get(0)).getName());
         listOfLists.remove(0);
         assertEquals("Rubber 1", ((Rubber) listOfLists.get(0)
-            .get(0)).getName());
+          .get(0)).getName());
     }
 
     @Test
@@ -67,10 +68,10 @@ public class ListOfListsUnitTest {
         list.add(rubbers);
 
         assertEquals("Pen 1", ((Pen) list.get(0)
-            .get(0)).getName());
+          .get(0)).getName());
         assertEquals("Pencil 1", ((Pencil) list.get(1)
-            .get(0)).getName());
+          .get(0)).getName());
         assertEquals("Rubber 1", ((Rubber) list.get(2)
-            .get(0)).getName());
+          .get(0)).getName());
     }
 }

core-java/src/test/java/com/baeldung/mappedbytebuffer/MappedByteBufferUnitTest.java

@@ -47,7 +47,7 @@ public class MappedByteBufferUnitTest {
 
         //when
         try (FileChannel fileChannel = (FileChannel) Files.newByteChannel(pathToWrite,
-                EnumSet.of(StandardOpenOption.READ, StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING))) {
+          EnumSet.of(StandardOpenOption.READ, StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING))) {
             MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, 0, charBuffer.length());
 
             if (mappedByteBuffer != null) {
@@ -61,7 +61,7 @@ public class MappedByteBufferUnitTest {
 
     }
 
-    public Path getFileURIFromResources(String fileName) throws Exception {
+    private Path getFileURIFromResources(String fileName) throws Exception {
         ClassLoader classLoader = getClass().getClassLoader();
         return Paths.get(classLoader.getResource(fileName).getPath());
     }

core-java/src/test/java/com/baeldung/maths/BigDecimalImplTest.java

@@ -1,9 +1,10 @@
 package com.baeldung.maths;
 
+import org.junit.Assert;
+import org.junit.Test;
+
 import java.math.BigDecimal;
 import java.math.RoundingMode;
-import org.junit.Assert;
-import org.junit.Test;
 
 public class BigDecimalImplTest {
 

core-java/src/test/java/com/baeldung/maths/BigIntegerImplTest.java

@@ -1,11 +1,10 @@
 package com.baeldung.maths;
 
-import java.math.BigInteger;
-
 import org.junit.Assert;
-
 import org.junit.Test;
 
+import java.math.BigInteger;
+
 public class BigIntegerImplTest {
 
     @Test

core-java/src/test/java/com/baeldung/maths/RoundTest.java

@@ -5,6 +5,9 @@ import org.decimal4j.util.DoubleRounder;
 import org.junit.Assert;
 import org.junit.Test;
 
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
 public class RoundTest {
     private double value = 2.03456d;
     private int places = 2;

core-java/src/test/java/com/baeldung/money/JavaMoneyUnitTest.java

@@ -3,13 +3,13 @@ package com.baeldung.money;
 import org.javamoney.moneta.FastMoney;
 import org.javamoney.moneta.Money;
 import org.javamoney.moneta.format.CurrencyStyle;
+import org.junit.Ignore;
 import org.junit.Test;
 
 import javax.money.CurrencyUnit;
 import javax.money.Monetary;
 import javax.money.MonetaryAmount;
 import javax.money.UnknownCurrencyException;
-import javax.money.convert.ConversionQueryBuilder;
 import javax.money.convert.CurrencyConversion;
 import javax.money.convert.MonetaryConversions;
 import javax.money.format.AmountFormatQueryBuilder;
@@ -19,7 +19,11 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.Locale;
 
-import static org.junit.Assert.*;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 public class JavaMoneyUnitTest {
 
@@ -36,17 +40,16 @@ public class JavaMoneyUnitTest {
     @Test(expected = UnknownCurrencyException.class)
     public void givenCurrencyCode_whenNoExist_thanThrowsError() {
         Monetary.getCurrency("AAA");
-        fail(); // if no exception
     }
 
     @Test
     public void givenAmounts_whenStringified_thanEquals() {
         CurrencyUnit usd = Monetary.getCurrency("USD");
         MonetaryAmount fstAmtUSD = Monetary
-                .getDefaultAmountFactory()
+          .getDefaultAmountFactory()
-                .setCurrency(usd)
+          .setCurrency(usd)
-                .setNumber(200)
+          .setNumber(200)
-                .create();
+          .create();
         Money moneyof = Money.of(12, usd);
         FastMoney fastmoneyof = FastMoney.of(2, usd);
 
@@ -59,10 +62,10 @@ public class JavaMoneyUnitTest {
     @Test
     public void givenCurrencies_whenCompared_thanNotequal() {
         MonetaryAmount oneDolar = Monetary
-                .getDefaultAmountFactory()
+          .getDefaultAmountFactory()
-                .setCurrency("USD")
+          .setCurrency("USD")
-                .setNumber(1)
+          .setNumber(1)
-                .create();
+          .create();
         Money oneEuro = Money.of(1, "EUR");
 
         assertFalse(oneEuro.equals(FastMoney.of(1, "EUR")));
@@ -72,10 +75,10 @@ public class JavaMoneyUnitTest {
     @Test(expected = ArithmeticException.class)
     public void givenAmount_whenDivided_thanThrowsException() {
         MonetaryAmount oneDolar = Monetary
-                .getDefaultAmountFactory()
+          .getDefaultAmountFactory()
-                .setCurrency("USD")
+          .setCurrency("USD")
-                .setNumber(1)
+          .setNumber(1)
-                .create();
+          .create();
         oneDolar.divide(3);
         fail(); // if no exception
     }
@@ -85,8 +88,8 @@ public class JavaMoneyUnitTest {
         List<MonetaryAmount> monetaryAmounts = Arrays.asList(Money.of(100, "CHF"), Money.of(10.20, "CHF"), Money.of(1.15, "CHF"));
 
         Money sumAmtCHF = (Money) monetaryAmounts
-                .stream()
+          .stream()
-                .reduce(Money.of(0, "CHF"), MonetaryAmount::add);
+          .reduce(Money.of(0, "CHF"), MonetaryAmount::add);
 
         assertEquals("CHF 111.35", sumAmtCHF.toString());
     }
@@ -97,18 +100,18 @@ public class JavaMoneyUnitTest {
 
         Money moneyof = Money.of(12, usd);
         MonetaryAmount fstAmtUSD = Monetary
-                .getDefaultAmountFactory()
+          .getDefaultAmountFactory()
-                .setCurrency(usd)
+          .setCurrency(usd)
-                .setNumber(200.50)
+          .setNumber(200.50)
-                .create();
+          .create();
         MonetaryAmount oneDolar = Monetary
-                .getDefaultAmountFactory()
+          .getDefaultAmountFactory()
-                .setCurrency("USD")
+          .setCurrency("USD")
-                .setNumber(1)
+          .setNumber(1)
-                .create();
+          .create();
         Money subtractedAmount = Money
-                .of(1, "USD")
+          .of(1, "USD")
-                .subtract(fstAmtUSD);
+          .subtract(fstAmtUSD);
         MonetaryAmount multiplyAmount = oneDolar.multiply(0.25);
         MonetaryAmount divideAmount = oneDolar.divide(0.25);
 
@@ -124,22 +127,23 @@ public class JavaMoneyUnitTest {
     @Test
     public void givenAmount_whenRounded_thanEquals() {
         MonetaryAmount fstAmtEUR = Monetary
-                .getDefaultAmountFactory()
+          .getDefaultAmountFactory()
-                .setCurrency("EUR")
+          .setCurrency("EUR")
-                .setNumber(1.30473908)
+          .setNumber(1.30473908)
-                .create();
+          .create();
         MonetaryAmount roundEUR = fstAmtEUR.with(Monetary.getDefaultRounding());
         assertEquals("EUR 1.30473908", fstAmtEUR.toString());
         assertEquals("EUR 1.3", roundEUR.toString());
     }
 
     @Test
+    @Ignore("Currency providers are not always available")
     public void givenAmount_whenConversion_thenNotNull() {
         MonetaryAmount oneDollar = Monetary
-                .getDefaultAmountFactory()
+          .getDefaultAmountFactory()
-                .setCurrency("USD")
+          .setCurrency("USD")
-                .setNumber(1)
+          .setNumber(1)
-                .create();
+          .create();
 
         CurrencyConversion conversionEUR = MonetaryConversions.getConversion("EUR");
 
@@ -152,10 +156,10 @@ public class JavaMoneyUnitTest {
     @Test
     public void givenLocale_whenFormatted_thanEquals() {
         MonetaryAmount oneDollar = Monetary
-                .getDefaultAmountFactory()
+          .getDefaultAmountFactory()
-                .setCurrency("USD")
+          .setCurrency("USD")
-                .setNumber(1)
+          .setNumber(1)
-                .create();
+          .create();
         MonetaryAmountFormat formatUSD = MonetaryFormats.getAmountFormat(Locale.US);
         String usFormatted = formatUSD.format(oneDollar);
 
@@ -167,16 +171,16 @@ public class JavaMoneyUnitTest {
     @Test
     public void givenAmount_whenCustomFormat_thanEquals() {
         MonetaryAmount oneDollar = Monetary
-                .getDefaultAmountFactory()
+          .getDefaultAmountFactory()
-                .setCurrency("USD")
+          .setCurrency("USD")
-                .setNumber(1)
+          .setNumber(1)
-                .create();
+          .create();
 
         MonetaryAmountFormat customFormat = MonetaryFormats.getAmountFormat(AmountFormatQueryBuilder
-                .of(Locale.US)
+          .of(Locale.US)
-                .set(CurrencyStyle.NAME)
+          .set(CurrencyStyle.NAME)
-                .set("pattern", "00000.00 ¤")
+          .set("pattern", "00000.00 ¤")
-                .build());
+          .build());
         String customFormatted = customFormat.format(oneDollar);
 
         assertNotNull(customFormat);

core-java/src/test/java/com/baeldung/regexp/EscapingCharsTest.java

@@ -1,12 +1,14 @@
 package com.baeldung.regexp;
 
-import static junit.framework.TestCase.assertEquals;
+import org.junit.Test;
-import static org.junit.Assert.assertThat;
+
-import static org.hamcrest.CoreMatchers.*;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import org.junit.Test;
+import static junit.framework.TestCase.assertEquals;
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.not;
+import static org.junit.Assert.assertThat;
 
 public class EscapingCharsTest {
     @Test
@@ -38,17 +40,17 @@ public class EscapingCharsTest {
         String strInput = "foo|bar|hello|world";
         String strRegex = "|";
 
-        assertEquals(4,strInput.split(Pattern.quote(strRegex)).length);
+        assertEquals(4, strInput.split(Pattern.quote(strRegex)).length);
     }
 
     @Test
     public void givenRegexWithDollar_whenReplacing_thenNotReplace() {
         String strInput = "I gave $50 to my brother."
-                + "He bought candy for $35. Now he has $15 left.";
+          + "He bought candy for $35. Now he has $15 left.";
         String strRegex = "$";
         String strReplacement = "£";
         String output = "I gave £50 to my brother."
-                + "He bought candy for £35. Now he has £15 left.";
+          + "He bought candy for £35. Now he has £15 left.";
         Pattern p = Pattern.compile(strRegex);
         Matcher m = p.matcher(strInput);
 
@@ -58,14 +60,14 @@ public class EscapingCharsTest {
     @Test
     public void givenRegexWithDollarEsc_whenReplacing_thenReplace() {
         String strInput = "I gave $50 to my brother."
-                + "He bought candy for $35. Now he has $15 left.";
+          + "He bought candy for $35. Now he has $15 left.";
         String strRegex = "\\$";
         String strReplacement = "£";
         String output = "I gave £50 to my brother."
-                + "He bought candy for £35. Now he has £15 left.";
+          + "He bought candy for £35. Now he has £15 left.";
         Pattern p = Pattern.compile(strRegex);
         Matcher m = p.matcher(strInput);
 
-        assertEquals(output,m.replaceAll(strReplacement));
+        assertEquals(output, m.replaceAll(strReplacement));
     }
 }

core-java/src/test/java/com/baeldung/scripting/NashornUnitTest.java

@@ -4,7 +4,11 @@ import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import javax.script.*;
+import javax.script.Bindings;
+import javax.script.Invocable;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
 import java.io.InputStreamReader;
 import java.util.List;
 import java.util.Map;

core-java/src/test/java/com/baeldung/serialization/PersonUnitTest.java

@@ -1,6 +1,6 @@
 package com.baeldung.serialization;
 
-import static org.junit.Assert.assertTrue;
+import org.junit.Test;
 
 import java.io.FileInputStream;
 import java.io.FileOutputStream;
@@ -8,57 +8,57 @@ import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 
-import org.junit.Test;
+import static org.junit.Assert.assertTrue;
 
 public class PersonUnitTest {
 
-	@Test
+    @Test
-	public void whenSerializingAndDeserializing_ThenObjectIsTheSame() throws IOException, ClassNotFoundException {
+    public void whenSerializingAndDeserializing_ThenObjectIsTheSame() throws IOException, ClassNotFoundException {
-		Person p = new Person();
+        Person p = new Person();
-		p.setAge(20);
+        p.setAge(20);
-		p.setName("Joe");
+        p.setName("Joe");
 
-		FileOutputStream fileOutputStream = new FileOutputStream("yofile.txt");
+        FileOutputStream fileOutputStream = new FileOutputStream("yofile.txt");
-		ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream);
+        ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream);
-		objectOutputStream.writeObject(p);
+        objectOutputStream.writeObject(p);
-		objectOutputStream.flush();
+        objectOutputStream.flush();
-		objectOutputStream.close();
+        objectOutputStream.close();
 
-		FileInputStream fileInputStream = new FileInputStream("yofile.txt");
+        FileInputStream fileInputStream = new FileInputStream("yofile.txt");
-		ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);
+        ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);
-		Person p2 = (Person) objectInputStream.readObject();
+        Person p2 = (Person) objectInputStream.readObject();
-		objectInputStream.close();
+        objectInputStream.close();
 
-		assertTrue(p2.getAge() == p.getAge());
+        assertTrue(p2.getAge() == p.getAge());
-		assertTrue(p2.getName().equals(p.getName()));
+        assertTrue(p2.getName().equals(p.getName()));
-	}
+    }
 
-	@Test
+    @Test
-	public void whenCustomSerializingAndDeserializing_ThenObjectIsTheSame() throws IOException, ClassNotFoundException {
+    public void whenCustomSerializingAndDeserializing_ThenObjectIsTheSame() throws IOException, ClassNotFoundException {
-		Person p = new Person();
+        Person p = new Person();
-		p.setAge(20);
+        p.setAge(20);
-		p.setName("Joe");
+        p.setName("Joe");
 
-		Address a = new Address();
+        Address a = new Address();
-		a.setHouseNumber(1);
+        a.setHouseNumber(1);
 
-		Employee e = new Employee();
+        Employee e = new Employee();
-		e.setPerson(p);
+        e.setPerson(p);
-		e.setAddress(a);
+        e.setAddress(a);
 
-		FileOutputStream fileOutputStream = new FileOutputStream("yofile2.txt");
+        FileOutputStream fileOutputStream = new FileOutputStream("yofile2.txt");
-		ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream);
+        ObjectOutputStream objectOutputStream = new ObjectOutputStream(fileOutputStream);
-		objectOutputStream.writeObject(e);
+        objectOutputStream.writeObject(e);
-		objectOutputStream.flush();
+        objectOutputStream.flush();
-		objectOutputStream.close();
+        objectOutputStream.close();
 
-		FileInputStream fileInputStream = new FileInputStream("yofile2.txt");
+        FileInputStream fileInputStream = new FileInputStream("yofile2.txt");
-		ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);
+        ObjectInputStream objectInputStream = new ObjectInputStream(fileInputStream);
-		Employee e2 = (Employee) objectInputStream.readObject();
+        Employee e2 = (Employee) objectInputStream.readObject();
-		objectInputStream.close();
+        objectInputStream.close();
 
-		assertTrue(e2.getPerson().getAge() == e.getPerson().getAge());
+        assertTrue(e2.getPerson().getAge() == e.getPerson().getAge());
-		assertTrue(e2.getAddress().getHouseNumber() == (e.getAddress().getHouseNumber()));
+        assertTrue(e2.getAddress().getHouseNumber() == (e.getAddress().getHouseNumber()));
-	}
+    }
 
 }

core-java/src/test/java/com/baeldung/socket/EchoIntegrationTest.java

@@ -1,14 +1,14 @@
 package com.baeldung.socket;
 
-import static org.junit.Assert.assertEquals;
-
-import java.util.concurrent.Executors;
-
 import org.junit.After;
 import org.junit.Before;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
+import java.util.concurrent.Executors;
+
+import static org.junit.Assert.assertEquals;
+
 public class EchoIntegrationTest {
     private static final Integer PORT = 4444;
 

core-java/src/test/java/com/baeldung/stackoverflowerror/CyclicDependancyManualTest.java

@@ -1,11 +1,10 @@
 package com.baeldung.stackoverflowerror;
 
-import static org.junit.Assert.fail;
 import org.junit.Test;
 
 public class CyclicDependancyManualTest {
     @Test(expected = StackOverflowError.class)
     public void whenInstanciatingClassOne_thenThrowsException() {
-            ClassOne obj = new ClassOne();
+        ClassOne obj = new ClassOne();
     }
 }

core-java/src/test/java/com/baeldung/stackoverflowerror/InfiniteRecursionWithTerminationConditionManualTest.java

@@ -1,9 +1,9 @@
 package com.baeldung.stackoverflowerror;
 
-import static junit.framework.TestCase.assertEquals;
-import static org.junit.Assert.fail;
 import org.junit.Test;
 
+import static junit.framework.TestCase.assertEquals;
+
 public class InfiniteRecursionWithTerminationConditionManualTest {
     @Test
     public void givenPositiveIntNoOne_whenCalcFact_thenCorrectlyCalc() {
@@ -23,9 +23,9 @@ public class InfiniteRecursionWithTerminationConditionManualTest {
 
     @Test(expected = StackOverflowError.class)
     public void givenNegativeInt_whenCalcFact_thenThrowsException() {
-            int numToCalcFactorial = -1;
+        int numToCalcFactorial = -1;
-            InfiniteRecursionWithTerminationCondition irtc = new InfiniteRecursionWithTerminationCondition();
+        InfiniteRecursionWithTerminationCondition irtc = new InfiniteRecursionWithTerminationCondition();
 
-            irtc.calculateFactorial(numToCalcFactorial);
+        irtc.calculateFactorial(numToCalcFactorial);
     }
 }

core-java/src/test/java/com/baeldung/stackoverflowerror/RecursionWithCorrectTerminationConditionManualTest.java

@@ -1,9 +1,9 @@
 package com.baeldung.stackoverflowerror;
 
-import static junit.framework.TestCase.assertEquals;
-
 import org.junit.Test;
 
+import static junit.framework.TestCase.assertEquals;
+
 public class RecursionWithCorrectTerminationConditionManualTest {
     @Test
     public void givenNegativeInt_whenCalcFact_thenCorrectlyCalc() {

core-java/src/test/java/com/baeldung/stackoverflowerror/UnintendedInfiniteRecursionManualTest.java

@@ -6,7 +6,7 @@ import org.junit.Test;
 public class UnintendedInfiniteRecursionManualTest {
     @Test(expected = StackOverflowError.class)
     public void givenPositiveIntNoOne_whenCalFact_thenThrowsException() {
-        int numToCalcFactorial= 1;
+        int numToCalcFactorial = 1;
         UnintendedInfiniteRecursion uir = new UnintendedInfiniteRecursion();
 
         uir.calculateFactorial(numToCalcFactorial);
@@ -14,7 +14,7 @@ public class UnintendedInfiniteRecursionManualTest {
 
     @Test(expected = StackOverflowError.class)
     public void givenPositiveIntGtOne_whenCalcFact_thenThrowsException() {
-        int numToCalcFactorial= 2;
+        int numToCalcFactorial = 2;
         UnintendedInfiniteRecursion uir = new UnintendedInfiniteRecursion();
 
         uir.calculateFactorial(numToCalcFactorial);
@@ -22,7 +22,7 @@ public class UnintendedInfiniteRecursionManualTest {
 
     @Test(expected = StackOverflowError.class)
     public void givenNegativeInt_whenCalcFact_thenThrowsException() {
-        int numToCalcFactorial= -1;
+        int numToCalcFactorial = -1;
         UnintendedInfiniteRecursion uir = new UnintendedInfiniteRecursion();
 
         uir.calculateFactorial(numToCalcFactorial);

core-java/src/test/java/com/baeldung/strategy/StrategyDesignPatternUnitTest.java

@@ -7,7 +7,9 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.function.Function;
 
-import static com.baeldung.strategy.Discounter.*;
+import static com.baeldung.strategy.Discounter.christmas;
+import static com.baeldung.strategy.Discounter.easter;
+import static com.baeldung.strategy.Discounter.newYear;
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class StrategyDesignPatternUnitTest {
@@ -26,7 +28,7 @@ public class StrategyDesignPatternUnitTest {
     public void shouldDivideByTwo_WhenApplyingStaffDiscounterWithAnonyousTypes() {
         Discounter staffDiscounter = new Discounter() {
             @Override
-            public BigDecimal apply( BigDecimal amount) {
+            public BigDecimal apply(BigDecimal amount) {
                 return amount.multiply(BigDecimal.valueOf(0.5));
             }
         };

core-java/src/test/java/com/baeldung/stream/InfiniteStreamUnitTest.java

@@ -5,7 +5,6 @@ import org.junit.Test;
 
 import java.util.Arrays;
 import java.util.List;
-import java.util.Random;
 import java.util.UUID;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
@@ -22,8 +21,8 @@ public class InfiniteStreamUnitTest {
 
         //when
         List<Integer> collect = infiniteStream
-                .limit(10)
+          .limit(10)
-                .collect(Collectors.toList());
+          .collect(Collectors.toList());
 
         //then
         assertEquals(collect, Arrays.asList(0, 2, 4, 6, 8, 10, 12, 14, 16, 18));
@@ -37,9 +36,9 @@ public class InfiniteStreamUnitTest {
 
         //when
         List<UUID> randomInts = infiniteStreamOfRandomUUID
-                .skip(10)
+          .skip(10)
-                .limit(10)
+          .limit(10)
-                .collect(Collectors.toList());
+          .collect(Collectors.toList());
 
         //then
         assertEquals(randomInts.size(), 10);

core-java/src/test/java/com/baeldung/stream/StreamAddUnitTest.java

@@ -1,10 +1,12 @@
 package com.baeldung.stream;
 
+import org.junit.Test;
+
 import java.util.List;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
+
 import static org.junit.Assert.assertEquals;
-import org.junit.Test;
 
 public class StreamAddUnitTest {
 
@@ -25,7 +27,7 @@ public class StreamAddUnitTest {
         Stream<Integer> newStream = Stream.concat(Stream.of(99), anStream);
 
         assertEquals(newStream.findFirst()
-            .get(), (Integer) 99);
+          .get(), (Integer) 99);
     }
 
     @Test
@@ -38,7 +40,7 @@ public class StreamAddUnitTest {
         assertEquals(resultList.get(3), (Double) 9.9);
     }
 
-    public <T> Stream<T> insertInStream(Stream<T> stream, T elem, int index) {
+    private <T> Stream<T> insertInStream(Stream<T> stream, T elem, int index) {
         List<T> result = stream.collect(Collectors.toList());
         result.add(index, elem);
         return result.stream();

core-java/src/test/java/com/baeldung/string/JoinerSplitterUnitTest.java

@@ -1,68 +1,66 @@
 package com.baeldung.string;
 
-import static org.junit.Assert.*;
+import org.junit.Test;
 
 import java.util.ArrayList;
 import java.util.List;
 
-import org.junit.Test;
+import static org.junit.Assert.assertEquals;
-
-import com.baeldung.string.JoinerSplitter;
 
 public class JoinerSplitterUnitTest {
 
-	@Test
+    @Test
-	public void provided_array_convert_to_stream_and_convert_to_string() {
+    public void provided_array_convert_to_stream_and_convert_to_string() {
 
-		String[] programming_languages = {"java", "python", "nodejs", "ruby"};
+        String[] programming_languages = {"java", "python", "nodejs", "ruby"};
 
-		String expectation = "java,python,nodejs,ruby";
+        String expectation = "java,python,nodejs,ruby";
 
-		String result  = JoinerSplitter.join(programming_languages);
+        String result = JoinerSplitter.join(programming_languages);
-		assertEquals(result, expectation);
+        assertEquals(result, expectation);
-	}
+    }
 
-	@Test
+    @Test
-	public void givenArray_transformedToStream_convertToPrefixPostfixString() {
+    public void givenArray_transformedToStream_convertToPrefixPostfixString() {
 
-		String[] programming_languages = {"java", "python", 
+        String[] programming_languages = {"java", "python",
-				"nodejs", "ruby"};
+          "nodejs", "ruby"};
-		String expectation = "[java,python,nodejs,ruby]";
+        String expectation = "[java,python,nodejs,ruby]";
 
-		String result  = JoinerSplitter.joinWithPrefixPostFix(programming_languages);
+        String result = JoinerSplitter.joinWithPrefixPostFix(programming_languages);
-		assertEquals(result, expectation);
+        assertEquals(result, expectation);
-	}
+    }
 
-	@Test
+    @Test
-	public void givenString_transformedToStream_convertToList() {
+    public void givenString_transformedToStream_convertToList() {
 
-		String programming_languages = "java,python,nodejs,ruby";
+        String programming_languages = "java,python,nodejs,ruby";
 
-		List<String> expectation = new ArrayList<String>();
+        List<String> expectation = new ArrayList<String>();
-		expectation.add("java");
+        expectation.add("java");
-		expectation.add("python");
+        expectation.add("python");
-		expectation.add("nodejs");
+        expectation.add("nodejs");
-		expectation.add("ruby");
+        expectation.add("ruby");
 
-		List<String> result  = JoinerSplitter.split(programming_languages);
+        List<String> result = JoinerSplitter.split(programming_languages);
 
-		assertEquals(result, expectation);
+        assertEquals(result, expectation);
-	}
+    }
 
-	@Test
+    @Test
-	public void givenString_transformedToStream_convertToListOfChar() {
+    public void givenString_transformedToStream_convertToListOfChar() {
 
-		String programming_languages = "java,python,nodejs,ruby";
+        String programming_languages = "java,python,nodejs,ruby";
 
-		List<Character> expectation = new ArrayList<Character>();
+        List<Character> expectation = new ArrayList<Character>();
-		char[] charArray = programming_languages.toCharArray();
+        char[] charArray = programming_languages.toCharArray();
-		for (char c : charArray) {
+        for (char c : charArray) {
-			expectation.add(c);
+            expectation.add(c);
-		}
+        }
 
-		List<Character> result  = JoinerSplitter.splitToListOfChar(programming_languages);
+        List<Character> result = JoinerSplitter.splitToListOfChar(programming_languages);
-		assertEquals(result, expectation);
+        assertEquals(result, expectation);
 
-	}
+    }
 
 }

core-java/src/test/java/com/baeldung/string/SplitUnitTest.java

@@ -2,7 +2,6 @@ package com.baeldung.string;
 
 import com.google.common.base.Splitter;
 import org.apache.commons.lang.StringUtils;
-import org.assertj.core.util.Lists;
 import org.junit.Test;
 
 import java.util.List;

core-java/src/test/java/com/baeldung/string/StringHelperUnitTest.java

@@ -1,9 +1,10 @@
 package com.baeldung.string;
 
+import org.apache.commons.lang3.StringUtils;
+import org.junit.Test;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotEquals;
-import org.apache.commons.lang3.StringUtils;
-import org.junit.Test;
 
 public class StringHelperUnitTest {
 

core-java/src/test/java/com/baeldung/temporaladjusters/CustomTemporalAdjusterTest.java

@@ -0,0 +1,56 @@
+package com.baeldung.temporaladjusters;
+
+import java.time.DayOfWeek;
+import java.time.LocalDate;
+import java.time.Period;
+import java.time.temporal.TemporalAdjuster;
+import java.time.temporal.TemporalAdjusters;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import com.baeldung.temporaladjuster.CustomTemporalAdjuster;
+
+public class CustomTemporalAdjusterTest {
+
+    @Test
+    public void whenAdjustAndImplementInterface_thenNextWorkingDay() {
+        LocalDate localDate = LocalDate.of(2017, 07, 8);
+        CustomTemporalAdjuster temporalAdjuster = new CustomTemporalAdjuster();
+        LocalDate nextWorkingDay = localDate.with(temporalAdjuster);
+
+        Assert.assertEquals("2017-07-10", nextWorkingDay.toString());
+    }
+
+    @Test
+    public void whenAdjust_thenNextWorkingDay() {
+        LocalDate localDate = LocalDate.of(2017, 07, 8);
+        TemporalAdjuster temporalAdjuster = NEXT_WORKING_DAY;
+        LocalDate date = localDate.with(temporalAdjuster);
+
+        Assert.assertEquals("2017-07-10", date.toString());
+    }
+
+    @Test
+    public void whenAdjust_thenFourteenDaysAfterDate() {
+        LocalDate localDate = LocalDate.of(2017, 07, 8);
+        TemporalAdjuster temporalAdjuster = (t) -> t.plus(Period.ofDays(14));
+        LocalDate result = localDate.with(temporalAdjuster);
+
+        String fourteenDaysAfterDate = "2017-07-22";
+
+        Assert.assertEquals(fourteenDaysAfterDate, result.toString());
+    }
+
+    static TemporalAdjuster NEXT_WORKING_DAY = TemporalAdjusters.ofDateAdjuster(date -> {
+        DayOfWeek dayOfWeek = date.getDayOfWeek();
+        int daysToAdd;
+        if (dayOfWeek == DayOfWeek.FRIDAY)
+            daysToAdd = 3;
+        else if (dayOfWeek == DayOfWeek.SATURDAY)
+            daysToAdd = 2;
+        else
+            daysToAdd = 1;
+        return date.plusDays(daysToAdd);
+    });
+}

core-java/src/test/java/com/baeldung/temporaladjusters/TemporalAdjustersTest.java

@@ -0,0 +1,22 @@
+package com.baeldung.temporaladjusters;
+
+import java.time.DayOfWeek;
+import java.time.LocalDate;
+import java.time.temporal.TemporalAdjusters;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class TemporalAdjustersTest {
+
+    @Test
+    public void whenAdjust_thenNextSunday() {
+        LocalDate localDate = LocalDate.of(2017, 07, 8);
+        LocalDate nextSunday = localDate.with(TemporalAdjusters.next(DayOfWeek.SUNDAY));
+
+        String expected = "2017-07-09";
+
+        Assert.assertEquals(expected, nextSunday.toString());
+    }
+
+}

core-java/src/test/java/com/baeldung/unsafe/OffHeapArray.java

@@ -15,7 +15,7 @@ class OffHeapArray {
         return (Unsafe) f.get(null);
     }
 
-    public OffHeapArray(long size) throws NoSuchFieldException, IllegalAccessException {
+    OffHeapArray(long size) throws NoSuchFieldException, IllegalAccessException {
         this.size = size;
         address = getUnsafe().allocateMemory(size * BYTE);
     }
@@ -32,7 +32,7 @@ class OffHeapArray {
         return size;
     }
 
-    public void freeMemory() throws NoSuchFieldException, IllegalAccessException {
+    void freeMemory() throws NoSuchFieldException, IllegalAccessException {
         getUnsafe().freeMemory(address);
     }
 

ejb/README.md

@@ -1,3 +1,4 @@
 ## Relevant articles:
 
 - [Guide to EJB Set-up](http://www.baeldung.com/ejb-intro)
+- [Java EE Session Beans](http://www.baeldung.com/ejb-session-beans)

guava/README.md

@@ -28,3 +28,4 @@
 - [Guide to Guava ClassToInstanceMap](http://www.baeldung.com/guava-class-to-instance-map)
 - [Guide to Guava MinMaxPriorityQueue and EvictingQueue](http://www.baeldung.com/guava-minmax-priority-queue-and-evicting-queue)
 - [Guide to Mathematical Utilities in Guava](http://www.baeldung.com/guava-math)
+- [Bloom Filter in Java using Guava](http://www.baeldung.com/guava-bloom-filter)

guava/src/main/java/org/baeldung/guava/CustomEvent.java

@@ -3,11 +3,11 @@ package org.baeldung.guava;
 public class CustomEvent {
     private String action;
 
-    public CustomEvent(String action) {
+    CustomEvent(String action) {
         this.action = action;
     }
 
-    public String getAction() {
+    String getAction() {
         return action;
     }
 

guava/src/main/java/org/baeldung/guava/EventListener.java

@@ -28,11 +28,11 @@ public class EventListener {
         eventsHandled++;
     }
 
-    public int getEventsHandled() {
+    int getEventsHandled() {
         return eventsHandled;
     }
 
-    public void resetEventsHandled() {
+    void resetEventsHandled() {
         eventsHandled = 0;
     }
 }

guava/src/test/java/org/baeldung/guava/BloomFilterTest.java

@@ -0,0 +1,54 @@
+package org.baeldung.guava;
+
+
+import com.google.common.hash.BloomFilter;
+import com.google.common.hash.Funnels;
+import org.junit.Test;
+
+import java.util.stream.IntStream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class BloomFilterTest {
+
+    @Test
+    public void givenBloomFilter_whenAddNStringsToIt_thenShouldNotReturnAnyFalsePositive() {
+        //when
+        BloomFilter<Integer> filter = BloomFilter.create(
+                Funnels.integerFunnel(),
+                500,
+                0.01);
+
+        //when
+        filter.put(1);
+        filter.put(2);
+        filter.put(3);
+
+        //then
+        // the probability that it returns true, but is actually false is 1%
+        assertThat(filter.mightContain(1)).isTrue();
+        assertThat(filter.mightContain(2)).isTrue();
+        assertThat(filter.mightContain(3)).isTrue();
+
+        assertThat(filter.mightContain(100)).isFalse();
+    }
+
+    @Test
+    public void givenBloomFilter_whenAddNStringsToItMoreThanDefinedExpectedInsertions_thenItWillReturnTrueForAlmostAllElements() {
+        //when
+        BloomFilter<Integer> filter = BloomFilter.create(
+                Funnels.integerFunnel(),
+                5,
+                0.01);
+
+        //when
+        IntStream.range(0, 100_000).forEach(filter::put);
+
+
+        //then
+        assertThat(filter.mightContain(1)).isTrue();
+        assertThat(filter.mightContain(2)).isTrue();
+        assertThat(filter.mightContain(3)).isTrue();
+        assertThat(filter.mightContain(1_000_000)).isTrue();
+    }
+}

guava/src/test/java/org/baeldung/guava/RateLimiterLongRunningUnitTest.java

@@ -0,0 +1,82 @@
+package org.baeldung.guava;
+
+
+import com.google.common.util.concurrent.RateLimiter;
+import org.junit.Test;
+
+import java.time.ZonedDateTime;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.IntStream;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+public class RateLimiterLongRunningUnitTest {
+
+    @Test
+    public void givenLimitedResource_whenUseRateLimiter_thenShouldLimitPermits() {
+        //given
+        RateLimiter rateLimiter = RateLimiter.create(100);
+
+        //when
+        long startTime = ZonedDateTime.now().getSecond();
+        IntStream.range(0, 1000).forEach(i -> {
+            rateLimiter.acquire();
+            doSomeLimitedOperation();
+        });
+        long elapsedTimeSeconds = ZonedDateTime.now().getSecond() - startTime;
+
+        //then
+        assertThat(elapsedTimeSeconds >= 10);
+    }
+
+    @Test
+    public void givenLimitedResource_whenRequestTwice_thenShouldPermitWithoutBlocking() {
+        //given
+        RateLimiter rateLimiter = RateLimiter.create(2);
+
+        //when
+        long startTime = ZonedDateTime.now().getSecond();
+        rateLimiter.acquire(1);
+        doSomeLimitedOperation();
+        rateLimiter.acquire(1);
+        doSomeLimitedOperation();
+        long elapsedTimeSeconds = ZonedDateTime.now().getSecond() - startTime;
+
+        //then
+        assertThat(elapsedTimeSeconds <= 1);
+    }
+
+    @Test
+    public void givenLimitedResource_whenRequestOnce_thenShouldPermitWithoutBlocking() {
+        //given
+        RateLimiter rateLimiter = RateLimiter.create(100);
+
+        //when
+        long startTime = ZonedDateTime.now().getSecond();
+        rateLimiter.acquire(100);
+        doSomeLimitedOperation();
+        long elapsedTimeSeconds = ZonedDateTime.now().getSecond() - startTime;
+
+        //then
+        assertThat(elapsedTimeSeconds <= 1);
+    }
+
+    @Test
+    public void givenLimitedResource_whenTryAcquire_shouldNotBlockIndefinitely() {
+        //given
+        RateLimiter rateLimiter = RateLimiter.create(1);
+
+        //when
+        rateLimiter.acquire();
+        boolean result = rateLimiter.tryAcquire(2, 10, TimeUnit.MILLISECONDS);
+
+        //then
+        assertThat(result).isFalse();
+
+    }
+
+    private void doSomeLimitedOperation() {
+        //some computing
+    }
+
+}

guava21/pom.xml

@@ -4,8 +4,7 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
 
-    <groupId>com.baeldung.guava</groupId>
+    <artifactId>guava21</artifactId>
-    <artifactId>tutorial</artifactId>
     <version>1.0-SNAPSHOT</version>
 
     <parent>
@@ -15,12 +14,17 @@
      </parent>
 
     <dependencies>
-        <!-- https://mvnrepository.com/artifact/com.google.guava/guava -->
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
             <version>21.0</version>
         </dependency>
+
+        <dependency>
+            <groupId>org.jooq</groupId>
+            <artifactId>jool</artifactId>
+            <version>0.9.12</version>
+        </dependency>
     </dependencies>
 
 

guava21/src/test/java/com.baeldung.guava.zip/ZipCollectionTest.java

@@ -0,0 +1,85 @@
+package com.baeldung.guava.zip;
+
+import com.google.common.collect.Streams;
+import org.jooq.lambda.Seq;
+import org.jooq.lambda.tuple.Tuple2;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import static org.junit.Assert.assertEquals;
+
+public class ZipCollectionTest {
+
+    private List<String> names;
+    private List<Integer> ages;
+    private List<String> expectedOutput;
+
+    @Before
+    public void setUp() throws Exception {
+        names = Arrays.asList("John", "Jane", "Jack", "Dennis");
+        ages = Arrays.asList(24, 25, 27);
+        expectedOutput = Arrays.asList("John:24", "Jane:25", "Jack:27");
+    }
+
+    @Test
+    public void zipCollectionUsingGuava21() {
+        List<String> output = Streams
+          .zip(names.stream(), ages.stream(), (name, age) -> name + ":" + age)
+          .collect(Collectors.toList());
+
+        assertEquals(output, expectedOutput);
+    }
+
+    @Test
+    public void zipCollectionUsingIntStream() {
+        List<String> output = IntStream
+          .range(0, Math.min(names.size(), ages.size()))
+          .mapToObj(i -> names.get(i) + ":" + ages.get(i))
+          .collect(Collectors.toList());
+
+        assertEquals(output, expectedOutput);
+    }
+
+    @Test
+    public void zipCollectionUsingJool() {
+        Seq<String> output = Seq
+          .of("John", "Jane", "Jack")
+          .zip(Seq.of(24, 25, 27), (x, y) -> x + ":" + y);
+
+        assertEquals(output.toList(), expectedOutput);
+    }
+
+    @Test
+    public void zipCollectionUsingJoolTuple() {
+        Seq<Tuple2<String, Integer>> output = Seq
+          .of("John", "Jane", "Dennis")
+          .zip(Seq.of(24, 25, 27));
+
+        Tuple2<String, Integer> element1 = new Tuple2<String, Integer>("John", 24);
+        Tuple2<String, Integer> element2 = new Tuple2<String, Integer>("Jane", 25);
+        Tuple2<String, Integer> element3 = new Tuple2<String, Integer>("Dennis", 27);
+
+        List<Tuple2> expectedOutput = Arrays.asList(element1, element2, element3);
+        assertEquals(output.collect(Collectors.toList()), expectedOutput);
+    }
+
+    @Test
+    public void zipCollectionUsingJoolWithIndex() {
+        Seq<Tuple2<String, Long>> output = Seq
+          .of("John", "Jane", "Dennis")
+          .zipWithIndex();
+
+        Tuple2<String, Long> element1 = new Tuple2<>("John", 0L);
+        Tuple2<String, Long> element2 = new Tuple2<>("Jane", 1L);
+        Tuple2<String, Long> element3 = new Tuple2<>("Dennis", 2L);
+
+        List<Tuple2> expectedOutput = Arrays.asList(element1, element2, element3);
+        assertEquals(output.collect(Collectors.toList()), expectedOutput);
+    }
+
+}

guava21/src/test/java/com/baeldung/guava/tutorial/AtomicLongMapIntegrationTest.java

@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.util.concurrent.AtomicLongMap;
 import org.junit.Test;
 

guava21/src/test/java/com/baeldung/guava/tutorial/ComparatorsUnitTest.java

@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.collect.Comparators;
 import org.junit.Assert;
 import org.junit.Test;

guava21/src/test/java/com/baeldung/guava/tutorial/GuavaStreamsUnitTest.java

@@ -1,21 +1,33 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.collect.Streams;
-import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 
-import java.util.*;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Optional;
+import java.util.OptionalDouble;
+import java.util.OptionalInt;
+import java.util.OptionalLong;
+import java.util.stream.Collectors;
 import java.util.stream.DoubleStream;
 import java.util.stream.IntStream;
 import java.util.stream.LongStream;
 import java.util.stream.Stream;
 
+import static com.baeldung.guava.tutorial.StreamUtility.assertStreamEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
 public class GuavaStreamsUnitTest {
 
-    List<Integer> numbers;
+    private List<Integer> numbers;
 
     @Before
     public void setUp() {
-        numbers = Arrays.asList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20);
+        numbers = IntStream.rangeClosed(1, 20).boxed().collect(Collectors.toList());
     }
 
     @Test
@@ -24,17 +36,17 @@ public class GuavaStreamsUnitTest {
         Stream streamFromCollection = Streams.stream(numbers);
 
         //Assert.assertNotNull(streamFromCollection);
-        StreamUtility.assertStreamEquals(streamFromCollection, numbers.stream());
+        assertStreamEquals(streamFromCollection, numbers.stream());
     }
 
     @Test
     public void createStreamsWithIterable() {
-        Iterable<Integer> numbersIterable = (Iterable<Integer>) numbers;
+        Iterable<Integer> numbersIterable = numbers;
 
         Stream streamFromIterable = Streams.stream(numbersIterable);
 
-        Assert.assertNotNull(streamFromIterable);
+        assertNotNull(streamFromIterable);
-        StreamUtility.assertStreamEquals(streamFromIterable, numbers.stream());
+        assertStreamEquals(streamFromIterable, numbers.stream());
     }
 
     @Test
@@ -43,8 +55,8 @@ public class GuavaStreamsUnitTest {
 
         Stream streamFromIterator = Streams.stream(numbersIterator);
 
-        Assert.assertNotNull(streamFromIterator);
+        assertNotNull(streamFromIterator);
-        StreamUtility.assertStreamEquals(streamFromIterator, numbers.stream());
+        assertStreamEquals(streamFromIterator, numbers.stream());
     }
 
     @Test
@@ -52,8 +64,8 @@ public class GuavaStreamsUnitTest {
 
         Stream streamFromOptional = Streams.stream(Optional.of(1));
 
-        Assert.assertNotNull(streamFromOptional);
+        assertNotNull(streamFromOptional);
-        Assert.assertEquals(streamFromOptional.count(), 1);
+        assertEquals(streamFromOptional.count(), 1);
     }
 
     @Test
@@ -61,8 +73,8 @@ public class GuavaStreamsUnitTest {
 
         LongStream streamFromOptionalLong = Streams.stream(OptionalLong.of(1));
 
-        Assert.assertNotNull(streamFromOptionalLong);
+        assertNotNull(streamFromOptionalLong);
-        Assert.assertEquals(streamFromOptionalLong.count(), 1);
+        assertEquals(streamFromOptionalLong.count(), 1);
     }
 
     @Test
@@ -71,7 +83,7 @@ public class GuavaStreamsUnitTest {
         IntStream streamFromOptionalInt = Streams.stream(OptionalInt.of(1));
 
         //Assert.assertNotNull(streamFromOptionalInt);
-        Assert.assertEquals(streamFromOptionalInt.count(), 1);
+        assertEquals(streamFromOptionalInt.count(), 1);
     }
 
     @Test
@@ -80,63 +92,54 @@ public class GuavaStreamsUnitTest {
         DoubleStream streamFromOptionalDouble = Streams.stream(OptionalDouble.of(1.0));
 
         //Assert.assertNotNull(streamFromOptionalDouble);
-        Assert.assertEquals(streamFromOptionalDouble.count(), 1);
+        assertEquals(streamFromOptionalDouble.count(), 1);
 
     }
 
     @Test
     public void concatStreamsOfSameType() {
-        Stream oddNumbers = Arrays
+        List<Integer> oddNumbers = Arrays
-          .asList(1, 3, 5, 7, 9, 11, 13, 15, 17, 19)
+          .asList(1, 3, 5, 7, 9, 11, 13, 15, 17, 19);
-          .stream();
+        List<Integer> evenNumbers = Arrays
-        Stream evenNumbers = Arrays
+          .asList(2, 4, 6, 8, 10, 12, 14, 16, 18, 20);
-          .asList(2, 4, 6, 8, 10, 12, 14, 16, 18, 20)
-          .stream();
 
-        Stream combinedStreams = Streams.concat(oddNumbers, evenNumbers);
+        Stream<Integer> combinedStreams = Streams.concat(oddNumbers.stream(), evenNumbers.stream());
 
         //Assert.assertNotNull(combinedStreams);
-        StreamUtility.assertStreamEquals(combinedStreams, Stream.concat(oddNumbers, evenNumbers));
+        assertStreamEquals(combinedStreams, Stream.concat(oddNumbers.stream(), evenNumbers.stream()));
     }
 
     @Test
     public void concatStreamsOfTypeLongStream() {
-        LongStream firstTwenty = LongStream.range(1, 20);
+        LongStream combinedStreams = Streams.concat(LongStream.range(1, 21), LongStream.range(21, 40));
-        LongStream nextTwenty = LongStream.range(21, 40);
 
-        LongStream combinedStreams = Streams.concat(firstTwenty, nextTwenty);
+        assertNotNull(combinedStreams);
-
+        assertStreamEquals(combinedStreams, LongStream.range(1, 40));
-        Assert.assertNotNull(combinedStreams);
-        StreamUtility.assertStreamEquals(combinedStreams, LongStream.concat(firstTwenty, nextTwenty));
     }
 
     @Test
     public void concatStreamsOfTypeIntStream() {
-        IntStream firstTwenty = IntStream.range(1, 20);
+        IntStream combinedStreams = Streams.concat(IntStream.range(1, 20), IntStream.range(21, 40));
-        IntStream nextTwenty = IntStream.range(21, 40);
 
-        IntStream combinedStreams = Streams.concat(firstTwenty, nextTwenty);
+        assertNotNull(combinedStreams);
-
+        assertStreamEquals(combinedStreams, IntStream.concat(IntStream.range(1, 20), IntStream.range(21, 40)));
-        Assert.assertNotNull(combinedStreams);
-        StreamUtility.assertStreamEquals(combinedStreams, IntStream.concat(firstTwenty, nextTwenty));
     }
 
     @Test
     public void findLastOfStream() {
         Optional<Integer> lastElement = Streams.findLast(numbers.stream());
 
-        Assert.assertNotNull(lastElement.get());
+        assertEquals(lastElement.get(), numbers.get(19));
-        Assert.assertEquals(lastElement.get(), numbers.get(20));
     }
 
     @Test
     public void mapWithIndexTest() {
-        Stream stringSream = Stream.of("a", "b", "c");
+        Stream<String> stringStream = Stream.of("a", "b", "c");
 
-        Stream<String> mappedStream = Streams.mapWithIndex(stringSream, (str, index) -> str + ":" + index);
+        Stream<String> mappedStream = Streams.mapWithIndex(stringStream, (str, index) -> str + ":" + index);
 
         //Assert.assertNotNull(mappedStream);
-        Assert.assertEquals(mappedStream
+        assertEquals(mappedStream
           .findFirst()
           .get(), "a:0");
 
@@ -144,12 +147,12 @@ public class GuavaStreamsUnitTest {
 
     @Test
     public void streamsZipTest() {
-        Stream stringSream = Stream.of("a", "b", "c");
+        Stream<String> stringSream = Stream.of("a", "b", "c");
-        Stream intStream = Stream.of(1, 2, 3);
+        Stream<Integer> intStream = Stream.of(1, 2, 3);
         Stream<String> mappedStream = Streams.zip(stringSream, intStream, (str, index) -> str + ":" + index);
 
         //Assert.assertNotNull(mappedStream);
-        Assert.assertEquals(mappedStream
+        assertEquals(mappedStream
           .findFirst()
           .get(), "a:1");
 

guava21/src/test/java/com/baeldung/guava/tutorial/InternBuilderUnitTest.java

@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.collect.Interner;
 import com.google.common.collect.Interners;
 import org.junit.Assert;

guava21/src/test/java/com/baeldung/guava/tutorial/MonitorUnitTest.java

@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.util.concurrent.Monitor;
 import org.junit.Assert;
 import org.junit.Test;

guava21/src/test/java/com/baeldung/guava/tutorial/MoreCollectorsUnitTest.java

@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import com.google.common.collect.MoreCollectors;
 import org.junit.Assert;
 import org.junit.Test;

guava21/src/test/java/com/baeldung/guava/tutorial/StreamUtility.java

@@ -1,3 +1,5 @@
+package com.baeldung.guava.tutorial;
+
 import org.junit.Assert;
 
 import java.util.Iterator;

javax-servlets/pom.xml

@@ -39,7 +39,7 @@
 
     <properties>
         <javax.servlet.version>3.1.0</javax.servlet.version>
-        <org.apache.httpcomponents.version>4.5.2</org.apache.httpcomponents.version>
+        <org.apache.httpcomponents.version>4.5.3</org.apache.httpcomponents.version>
     </properties>
 
 </project>

javax-servlets/src/test/java/com/baeldung/servlets/FormServletLiveTest.java

@@ -1,24 +1,24 @@
 package com.baeldung.servlets;
 
-import static org.junit.Assert.assertEquals;
-
-import java.util.ArrayList;
-import java.util.List;
-
 import org.apache.http.HttpResponse;
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.entity.UrlEncodedFormEntity;
 import org.apache.http.client.methods.HttpPost;
-import org.apache.http.impl.client.DefaultHttpClient;
+import org.apache.http.impl.client.HttpClientBuilder;
 import org.apache.http.message.BasicNameValuePair;
 import org.junit.Test;
 
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
 public class FormServletLiveTest {
 
     @Test
     public void whenPostRequestUsingHttpClient_thenCorrect() throws Exception {
 
-        HttpClient client = new DefaultHttpClient();
+        HttpClient client = HttpClientBuilder.create().build();
         HttpPost method = new HttpPost("http://localhost:8080/calculateServlet");
 
         List<BasicNameValuePair> nvps = new ArrayList<>();

json-path/pom.xml

@@ -23,6 +23,6 @@
 
     <properties>
         <!-- json-path -->
-        <json-path.version>2.2.0</json-path.version>
+        <json-path.version>2.4.0</json-path.version>
     </properties>
 </project>

json-path/src/test/java/com/baeldung/jsonpath/introduction/OperationIntegrationTest.java

@@ -1,10 +1,10 @@
 package com.baeldung.jsonpath.introduction;
 
-import static org.junit.Assert.assertEquals;
+import com.jayway.jsonpath.Criteria;
-import static org.junit.Assert.assertThat;
+import com.jayway.jsonpath.DocumentContext;
-import static org.hamcrest.CoreMatchers.containsString;
+import com.jayway.jsonpath.Filter;
-import static org.hamcrest.CoreMatchers.not;
+import com.jayway.jsonpath.JsonPath;
-
+import com.jayway.jsonpath.Predicate;
 import org.junit.Test;
 
 import java.io.InputStream;
@@ -12,15 +12,14 @@ import java.util.List;
 import java.util.Map;
 import java.util.Scanner;
 
-import com.jayway.jsonpath.Criteria;
+import static org.hamcrest.CoreMatchers.containsString;
-import com.jayway.jsonpath.DocumentContext;
+import static org.hamcrest.CoreMatchers.not;
-import com.jayway.jsonpath.Filter;
+import static org.junit.Assert.assertEquals;
-import com.jayway.jsonpath.JsonPath;
+import static org.junit.Assert.assertThat;
-import com.jayway.jsonpath.Predicate;
 
 public class OperationIntegrationTest {
-    InputStream jsonInputStream = this.getClass().getClassLoader().getResourceAsStream("intro_api.json");
+    private InputStream jsonInputStream = this.getClass().getClassLoader().getResourceAsStream("intro_api.json");
-    String jsonDataSourceString = new Scanner(jsonInputStream, "UTF-8").useDelimiter("\\Z").next();
+    private String jsonDataSourceString = new Scanner(jsonInputStream, "UTF-8").useDelimiter("\\Z").next();
 
     @Test
     public void givenJsonPathWithoutPredicates_whenReading_thenCorrect() {
@@ -46,12 +45,7 @@ public class OperationIntegrationTest {
 
     @Test
     public void givenJsonPathWithCustomizedPredicate_whenReading_thenCorrect() {
-        Predicate expensivePredicate = new Predicate() {
+        Predicate expensivePredicate = context -> Float.valueOf(context.item(Map.class).get("price").toString()) > 20.00;
-            public boolean apply(PredicateContext context) {
-                String value = context.item(Map.class).get("price").toString();
-                return Float.valueOf(value) > 20.00;
-            }
-        };
         List<Map<String, Object>> expensive = JsonPath.parse(jsonDataSourceString).read("$['book'][?]", expensivePredicate);
         predicateUsageAssertionHelper(expensive);
     }

json-path/src/test/java/com/baeldung/jsonpath/introduction/ServiceTest.java

@@ -1,9 +1,9 @@
 package com.baeldung.jsonpath.introduction;
 
-import static org.junit.Assert.assertThat;
+import com.jayway.jsonpath.Configuration;
-import static org.junit.Assert.assertEquals;
+import com.jayway.jsonpath.DocumentContext;
-import static org.hamcrest.CoreMatchers.containsString;
+import com.jayway.jsonpath.JsonPath;
-
+import com.jayway.jsonpath.Option;
 import org.junit.Test;
 
 import java.io.InputStream;
@@ -13,14 +13,13 @@ import java.util.List;
 import java.util.Map;
 import java.util.Scanner;
 
-import com.jayway.jsonpath.Configuration;
+import static org.hamcrest.CoreMatchers.containsString;
-import com.jayway.jsonpath.DocumentContext;
+import static org.junit.Assert.assertEquals;
-import com.jayway.jsonpath.JsonPath;
+import static org.junit.Assert.assertThat;
-import com.jayway.jsonpath.Option;
 
 public class ServiceTest {
-    InputStream jsonInputStream = this.getClass().getClassLoader().getResourceAsStream("intro_service.json");
+    private InputStream jsonInputStream = this.getClass().getClassLoader().getResourceAsStream("intro_service.json");
-    String jsonString = new Scanner(jsonInputStream, "UTF-8").useDelimiter("\\Z").next();
+    private String jsonString = new Scanner(jsonInputStream, "UTF-8").useDelimiter("\\Z").next();
 
     @Test
     public void givenId_whenRequestingRecordData_thenSucceed() {

junit5/README.md

@@ -4,3 +4,4 @@
 - [Guide to Dynamic Tests in Junit 5](http://www.baeldung.com/junit5-dynamic-tests)
 - [A Guide to @RepeatedTest in Junit 5](http://www.baeldung.com/junit-5-repeated-test)
 - [Guide to Dynamic Tests in Junit 5](http://www.baeldung.com/junit5-dynamic-tests)
+- [A Guied to JUnit 5 Extensions](http://www.baeldung.com/junit-5-extensions)

junit5/pom.xml

@@ -19,14 +19,24 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <java.version>1.8</java.version>
-        <junit.jupiter.version>5.0.0-M4</junit.jupiter.version>
+        <junit.jupiter.version>5.0.0-M5</junit.jupiter.version>
-        <junit.platform.version>1.0.0-M4</junit.platform.version>
+        <junit.platform.version>1.0.0-M5</junit.platform.version>
+        <junit.vintage.version>4.12.0-M5</junit.vintage.version>
+        <log4j2.version>2.8.2</log4j2.version>
+        <h2.version>1.4.196</h2.version>
 
         <maven-compiler-plugin.version>3.6.0</maven-compiler-plugin.version>
         <maven-surefire-plugin.version>2.19.1</maven-surefire-plugin.version>
+        <junit4.version>4.12</junit4.version>
     </properties>
 
     <build>
+        <resources>
+            <resource>
+                <directory>src/test/resources</directory>
+                <filtering>true</filtering>
+            </resource>
+        </resources>
         <plugins>
             <plugin>
                 <artifactId>maven-compiler-plugin</artifactId>
@@ -47,6 +57,21 @@
                     </dependency>
                 </dependencies>
             </plugin>
+            <plugin>
+                <groupId>org.codehaus.mojo</groupId>
+                <artifactId>exec-maven-plugin</artifactId>
+                <version>1.6.0</version>
+                <executions>
+                    <execution>
+                        <goals>
+                            <goal>java</goal>
+                        </goals>
+                    </execution>
+                </executions>
+                <configuration>
+                    <mainClass>com.baeldung.TestLauncher</mainClass>
+                </configuration>
+            </plugin>
         </plugins>
     </build>
 
@@ -57,5 +82,35 @@
             <version>${junit.jupiter.version}</version>
             <scope>test</scope>
         </dependency>
+        <dependency>
+            <groupId>org.junit.platform</groupId>
+            <artifactId>junit-platform-runner</artifactId>
+            <version>${junit.platform.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.vintage</groupId>
+            <artifactId>junit-vintage-engine</artifactId>
+            <version>${junit.vintage.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.logging.log4j</groupId>
+            <artifactId>log4j-core</artifactId>
+            <version>${log4j2.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.h2database</groupId>
+            <artifactId>h2</artifactId>
+            <version>${h2.version}</version>
+        </dependency>
+          <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>${junit4.version}</version>
+            <scope>test</scope>
+        </dependency>
+        
     </dependencies>
+  
 </project>

junit5/src/test/java/com/baeldung/EmployeesTest.java

@@ -0,0 +1,48 @@
+package com.baeldung;
+
+import java.sql.SQLException;
+
+import org.apache.logging.log4j.Logger;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import com.baeldung.extensions.EmployeeDaoParameterResolver;
+import com.baeldung.extensions.EmployeeDatabaseSetupExtension;
+import com.baeldung.extensions.EnvironmentExtension;
+import com.baeldung.extensions.IgnoreFileNotFoundExceptionExtension;
+import com.baeldung.extensions.LoggingExtension;
+import com.baeldung.helpers.Employee;
+import com.baeldung.helpers.EmployeeJdbcDao;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@ExtendWith({ EnvironmentExtension.class, EmployeeDatabaseSetupExtension.class, EmployeeDaoParameterResolver.class })
+@ExtendWith(LoggingExtension.class)
+@ExtendWith(IgnoreFileNotFoundExceptionExtension.class)
+public class EmployeesTest {
+
+    private EmployeeJdbcDao employeeDao;
+
+    private Logger logger;
+
+    public EmployeesTest(EmployeeJdbcDao employeeDao) {
+        this.employeeDao = employeeDao;
+    }
+
+    @Test
+    public void whenAddEmployee_thenGetEmployee() throws SQLException {
+        Employee emp = new Employee(1, "john");
+        employeeDao.add(emp);
+        assertEquals(1, employeeDao.findAll().size());
+    }
+
+    @Test
+    public void whenGetEmployees_thenEmptyList() throws SQLException {
+        assertEquals(0, employeeDao.findAll().size());
+    }
+
+    public void setLogger(Logger logger) {
+        this.logger = logger;
+    }
+
+}

junit5/src/test/java/com/baeldung/TestLauncher.java

@@ -0,0 +1,37 @@
+package com.baeldung;
+
+import org.junit.platform.launcher.LauncherDiscoveryRequest;
+import org.junit.platform.launcher.TestExecutionListener;
+import org.junit.platform.launcher.TestPlan;
+import org.junit.platform.launcher.core.LauncherDiscoveryRequestBuilder;
+import org.junit.platform.launcher.core.LauncherFactory;
+import org.junit.platform.launcher.listeners.SummaryGeneratingListener;
+
+import static org.junit.platform.engine.discovery.DiscoverySelectors.selectClass;
+
+import java.io.PrintWriter;
+
+import org.junit.platform.launcher.Launcher;
+
+public class TestLauncher {
+    public static void main(String[] args) {
+
+        //@formatter:off
+        LauncherDiscoveryRequest request = LauncherDiscoveryRequestBuilder.request()
+                .selectors(selectClass("com.baeldung.EmployeesTest"))
+                .configurationParameter("junit.conditions.deactivate", "com.baeldung.extensions.*")
+                .configurationParameter("junit.extensions.autodetection.enabled", "true")
+                .build();
+        
+        //@formatter:on
+
+        TestPlan plan = LauncherFactory.create().discover(request);
+        Launcher launcher = LauncherFactory.create();
+        SummaryGeneratingListener summaryGeneratingListener = new SummaryGeneratingListener();
+        launcher.execute(request, new TestExecutionListener[] { summaryGeneratingListener });
+        launcher.execute(request);
+
+        summaryGeneratingListener.getSummary().printTo(new PrintWriter(System.out));
+
+    }
+}

junit5/src/test/java/com/baeldung/extensions/EmployeeDaoParameterResolver.java

@@ -0,0 +1,23 @@
+package com.baeldung.extensions;
+
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.ParameterContext;
+import org.junit.jupiter.api.extension.ParameterResolutionException;
+import org.junit.jupiter.api.extension.ParameterResolver;
+
+import com.baeldung.helpers.EmployeeJdbcDao;
+import com.baeldung.helpers.JdbcConnectionUtil;
+
+public class EmployeeDaoParameterResolver implements ParameterResolver {
+
+    @Override
+    public boolean supportsParameter(ParameterContext parameterContext, ExtensionContext extensionContext) throws ParameterResolutionException {
+        return parameterContext.getParameter().getType().equals(EmployeeJdbcDao.class);
+    }
+
+    @Override
+    public Object resolveParameter(ParameterContext parameterContext, ExtensionContext extensionContext) throws ParameterResolutionException {
+        return new EmployeeJdbcDao(JdbcConnectionUtil.getConnection());
+    }
+
+}

junit5/src/test/java/com/baeldung/extensions/EmployeeDatabaseSetupExtension.java

@@ -0,0 +1,46 @@
+package com.baeldung.extensions;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.sql.Savepoint;
+
+import org.junit.jupiter.api.extension.AfterAllCallback;
+import org.junit.jupiter.api.extension.AfterEachCallback;
+import org.junit.jupiter.api.extension.BeforeAllCallback;
+import org.junit.jupiter.api.extension.BeforeEachCallback;
+import org.junit.jupiter.api.extension.ExtensionContext;
+
+import com.baeldung.helpers.EmployeeJdbcDao;
+import com.baeldung.helpers.JdbcConnectionUtil;
+
+public class EmployeeDatabaseSetupExtension implements BeforeAllCallback, AfterAllCallback, BeforeEachCallback, AfterEachCallback {
+
+    private Connection con = JdbcConnectionUtil.getConnection();
+    private EmployeeJdbcDao employeeDao = new EmployeeJdbcDao(con);
+    private Savepoint savepoint;
+
+    @Override
+    public void afterAll(ExtensionContext context) throws SQLException {
+        if (con != null) {
+            con.close();
+        }
+    }
+
+    @Override
+    public void beforeAll(ExtensionContext context) throws SQLException {
+        employeeDao.createTable();
+
+    }
+
+    @Override
+    public void afterEach(ExtensionContext context) throws SQLException {
+        con.rollback(savepoint);
+    }
+
+    @Override
+    public void beforeEach(ExtensionContext context) throws SQLException {
+        con.setAutoCommit(false);
+        savepoint = con.setSavepoint("before");
+    }
+
+}

junit5/src/test/java/com/baeldung/extensions/EnvironmentExtension.java

@@ -0,0 +1,27 @@
+package com.baeldung.extensions;
+
+import java.io.IOException;
+import java.util.Properties;
+
+import org.junit.jupiter.api.extension.ConditionEvaluationResult;
+import org.junit.jupiter.api.extension.ExecutionCondition;
+import org.junit.jupiter.api.extension.ExtensionContext;
+
+public class EnvironmentExtension implements ExecutionCondition {
+
+    @Override
+    public ConditionEvaluationResult evaluateExecutionCondition(ExtensionContext context) {
+        Properties props = new Properties();
+
+        try {
+            props.load(EnvironmentExtension.class.getResourceAsStream("application.properties"));
+            String env = props.getProperty("env");
+            if ("qa".equalsIgnoreCase(env)) {
+                return ConditionEvaluationResult.disabled("Test disabled on QA environment");
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+        return ConditionEvaluationResult.enabled("Test enabled on QA environment");
+    }
+}

junit5/src/test/java/com/baeldung/extensions/IgnoreFileNotFoundExceptionExtension.java

@@ -0,0 +1,23 @@
+package com.baeldung.extensions;
+
+import java.io.FileNotFoundException;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.TestExecutionExceptionHandler;
+
+public class IgnoreFileNotFoundExceptionExtension implements TestExecutionExceptionHandler {
+
+    Logger logger = LogManager.getLogger(IgnoreFileNotFoundExceptionExtension.class);
+
+    @Override
+    public void handleTestExecutionException(ExtensionContext context, Throwable throwable) throws Throwable {
+
+        if (throwable instanceof FileNotFoundException) {
+            logger.error("File not found:" + throwable.getMessage());
+            return;
+        }
+        throw throwable;
+    }
+}

junit5/src/test/java/com/baeldung/extensions/LoggingExtension.java

@@ -0,0 +1,16 @@
+package com.baeldung.extensions;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.TestInstancePostProcessor;
+
+public class LoggingExtension implements TestInstancePostProcessor {
+
+    @Override
+    public void postProcessTestInstance(Object testInstance, ExtensionContext context) throws Exception {
+        Logger logger = LogManager.getLogger(testInstance.getClass());
+        testInstance.getClass().getMethod("setLogger", Logger.class).invoke(testInstance, logger);
+    }
+
+}

junit5/src/test/java/com/baeldung/helpers/EmployeeJdbcDao.java

@@ -0,0 +1,51 @@
+package com.baeldung.helpers;
+
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+public class EmployeeJdbcDao {
+
+    private Connection con;
+
+    public EmployeeJdbcDao(Connection con) {
+        this.con = con;
+    }
+
+    public void createTable() throws SQLException {
+        String createQuery = "CREATE TABLE employees(id long primary key, firstName varchar(50))";
+        PreparedStatement pstmt = con.prepareStatement(createQuery);
+
+        pstmt.execute();
+    }
+
+    public void add(Employee emp) throws SQLException {
+        String insertQuery = "INSERT INTO employees(id, firstName) VALUES(?,?)";
+        PreparedStatement pstmt = con.prepareStatement(insertQuery);
+        pstmt.setLong(1, emp.getId());
+        pstmt.setString(2, emp.getFirstName());
+
+        pstmt.executeUpdate();
+
+    }
+
+    public List<Employee> findAll() throws SQLException {
+        List<Employee> employees = new ArrayList<>();
+        String query = "SELECT * FROM employees";
+        PreparedStatement pstmt = con.prepareStatement(query);
+
+        ResultSet rs = pstmt.executeQuery();
+        while (rs.next()) {
+            Employee emp = new Employee(rs.getLong("id"), rs.getString("firstName"));
+            employees.add(emp);
+        }
+
+        return employees;
+    }
+}

junit5/src/test/java/com/baeldung/helpers/JdbcConnectionUtil.java

@@ -0,0 +1,32 @@
+package com.baeldung.helpers;
+
+import java.io.IOException;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.SQLException;
+import java.util.Properties;
+
+public class JdbcConnectionUtil {
+
+    private static Connection con;
+
+    public static Connection getConnection() {
+        if (con == null) {
+            try {
+                Properties props = new Properties();
+                props.load(JdbcConnectionUtil.class.getResourceAsStream("jdbc.properties"));
+                Class.forName(props.getProperty("jdbc.driver"));
+                con = DriverManager.getConnection(props.getProperty("jdbc.url"), props.getProperty("jdbc.user"), props.getProperty("jdbc.password"));
+                return con;
+            } catch (IOException exc) {
+                exc.printStackTrace();
+            } catch (ClassNotFoundException exc) {
+                exc.printStackTrace();
+            } catch (SQLException exc) {
+                exc.printStackTrace();
+            }
+            return null;
+        }
+        return con;
+    }
+}

junit5/src/test/java/com/baeldung/migration/junit4/AnnotationTestExampleTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.migration.junit4;
+
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+import com.baeldung.migration.junit4.categories.Annotations;
+import com.baeldung.migration.junit4.categories.JUnit4Tests;
+
+@Category(value = { Annotations.class, JUnit4Tests.class })
+public class AnnotationTestExampleTest {
+    @Test(expected = Exception.class)
+    public void shouldRaiseAnException() throws Exception {
+        throw new Exception("This is my expected exception");
+    }
+
+    @Test(timeout = 1)
+    @Ignore
+    public void shouldFailBecauseTimeout() throws InterruptedException {
+        Thread.sleep(10);
+    }
+
+}

junit5/src/test/java/com/baeldung/migration/junit4/AssertionsExampleTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.migration.junit4;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.Arrays;
+import java.util.List;
+
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class AssertionsExampleTest {
+    @Test
+    @Ignore
+    public void shouldFailBecauseTheNumbersAreNotEqualld() {
+        assertEquals("Numbers are not equal!", 2, 3);
+    }
+
+    @Test
+    public void shouldAssertAllTheGroup() {
+        List<Integer> list = Arrays.asList(1, 2, 3);
+        assertEquals("List is not incremental", list.get(0)
+            .intValue(), 1);
+        assertEquals("List is not incremental", list.get(1)
+            .intValue(), 2);
+        assertEquals("List is not incremental", list.get(2)
+            .intValue(), 3);
+    }
+}