merge from upstream

JGit/pom.xml

@@ -3,10 +3,11 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
-    <artifactId>JGitSnippets</artifactId>
+    <artifactId>JGit</artifactId>
     <version>1.0-SNAPSHOT</version>
     <packaging>jar</packaging>
     <url>http://maven.apache.org</url>
+	<name>JGit</name>
 
     <parent>
         <groupId>com.baeldung</groupId>

algorithms/src/main/java/com/baeldung/algorithms/distancebetweenpoints/DistanceBetweenPointsService.java

@@ -0,0 +1,38 @@
+package com.baeldung.algorithms.distancebetweenpoints;
+
+import java.awt.geom.Point2D;
+
+public class DistanceBetweenPointsService {
+
+    public double calculateDistanceBetweenPoints(
+        double x1, 
+        double y1, 
+        double x2, 
+        double y2) {
+        
+        return Math.sqrt((y2 - y1) * (y2 - y1) + (x2 - x1) * (x2 - x1));
+    }
+
+    public double calculateDistanceBetweenPointsWithHypot(
+        double x1, 
+        double y1, 
+        double x2, 
+        double y2) {
+        
+        double ac = Math.abs(y2 - y1);
+        double cb = Math.abs(x2 - x1);
+        
+        return Math.hypot(ac, cb);
+    }
+
+    public double calculateDistanceBetweenPointsWithPoint2D( 
+        double x1, 
+        double y1, 
+        double x2, 
+        double y2) {
+        
+        return Point2D.distance(x1, y1, x2, y2);
+
+    }
+
+}

algorithms/src/main/java/com/baeldung/algorithms/rectanglesoverlap/Point.java

@@ -0,0 +1,29 @@
+package com.baeldung.algorithms.rectanglesoverlap;
+
+public class Point {
+
+    private int x;
+    private int y;
+
+    public Point(int x, int y) {
+        this.x = x;
+        this.y = y;
+    }
+
+    public int getX() {
+        return x;
+    }
+
+    public void setX(int x) {
+        this.x = x;
+    }
+
+    public int getY() {
+        return y;
+    }
+
+    public void setY(int y) {
+        this.y = y;
+    }
+
+}

algorithms/src/main/java/com/baeldung/algorithms/rectanglesoverlap/Rectangle.java

@@ -0,0 +1,40 @@
+package com.baeldung.algorithms.rectanglesoverlap;
+
+public class Rectangle {
+
+    private Point bottomLeft;
+    private Point topRight;
+
+    public Rectangle(Point bottomLeft, Point topRight) {
+        this.bottomLeft = bottomLeft;
+        this.topRight = topRight;
+    }
+
+    public Point getBottomLeft() {
+        return bottomLeft;
+    }
+
+    public void setBottomLeft(Point bottomLeft) {
+        this.bottomLeft = bottomLeft;
+    }
+
+    public Point getTopRight() {
+        return topRight;
+    }
+
+    public void setTopRight(Point topRight) {
+        this.topRight = topRight;
+    }
+
+    public boolean isOverlapping(Rectangle other) {
+        // one rectangle is to the top of the other
+        if (this.topRight.getY() < other.bottomLeft.getY() || this.bottomLeft.getY() > other.topRight.getY()) {
+            return false;
+        }
+        // one rectangle is to the left of the other
+        if (this.topRight.getX() < other.bottomLeft.getX() || this.bottomLeft.getX() > other.topRight.getX()) {
+            return false;
+        }
+        return true;
+    }
+}

algorithms/src/test/java/com/baeldung/algorithms/distancebetweenpoints/DistanceBetweenPointsServiceUnitTest.java

@@ -0,0 +1,54 @@
+package com.baeldung.algorithms.distancebetweenpoints;
+
+import org.junit.Test;
+
+import com.baeldung.algorithms.distancebetweenpoints.DistanceBetweenPointsService;
+
+import static org.junit.Assert.assertEquals;
+
+public class DistanceBetweenPointsServiceUnitTest {
+
+    private DistanceBetweenPointsService service = new DistanceBetweenPointsService();
+
+    @Test
+    public void givenTwoPoints_whenCalculateDistanceByFormula_thenCorrect() {
+
+        double x1 = 3;
+        double y1 = 4;
+        double x2 = 7;
+        double y2 = 1;
+
+        double distance = service.calculateDistanceBetweenPoints(x1, y1, x2, y2);
+
+        assertEquals(distance, 5, 0.001);
+
+    }
+
+    @Test
+    public void givenTwoPoints_whenCalculateDistanceWithHypot_thenCorrect() {
+
+        double x1 = 3;
+        double y1 = 4;
+        double x2 = 7;
+        double y2 = 1;
+
+        double distance = service.calculateDistanceBetweenPointsWithHypot(x1, y1, x2, y2);
+
+        assertEquals(distance, 5, 0.001);
+
+    }
+
+    @Test
+    public void givenTwoPoints_whenCalculateDistanceWithPoint2D_thenCorrect() {
+
+        double x1 = 3;
+        double y1 = 4;
+        double x2 = 7;
+        double y2 = 1;
+
+        double distance = service.calculateDistanceBetweenPointsWithPoint2D(x1, y1, x2, y2);
+
+        assertEquals(distance, 5, 0.001);
+
+    }
+}

algorithms/src/test/java/com/baeldung/algorithms/rectanglesoverlap/RectangleUnitTest.java

@@ -0,0 +1,42 @@
+package com.baeldung.algorithms.rectanglesoverlap;
+
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.assertFalse;
+import org.junit.Test;
+
+import com.baeldung.algorithms.rectanglesoverlap.Point;
+import com.baeldung.algorithms.rectanglesoverlap.Rectangle;
+
+public class RectangleUnitTest {
+
+    @Test
+    public void givenTwoOverlappingRectangles_whenisOverlappingCalled_shouldReturnTrue() {
+        Rectangle rectangle1 = new Rectangle(new Point(2, 1), new Point(4, 3));
+        Rectangle rectangle2 = new Rectangle(new Point(1, 1), new Point(6, 4));
+        assertTrue(rectangle1.isOverlapping(rectangle2));
+
+        rectangle1 = new Rectangle(new Point(-5, -2), new Point(2, 3));
+        rectangle2 = new Rectangle(new Point(-2, -1), new Point(5, 2));
+        assertTrue(rectangle1.isOverlapping(rectangle2));
+
+        rectangle1 = new Rectangle(new Point(-5, 1), new Point(2, 4));
+        rectangle2 = new Rectangle(new Point(-2, -2), new Point(5, 5));
+        assertTrue(rectangle1.isOverlapping(rectangle2));
+    }
+
+    @Test
+    public void givenTwoNonOverlappingRectangles_whenisOverlappingCalled_shouldReturnFalse() {
+        Rectangle rectangle1 = new Rectangle(new Point(-5, 1), new Point(-3, 4));
+        Rectangle rectangle2 = new Rectangle(new Point(-2, -2), new Point(5, 5));
+        assertFalse(rectangle1.isOverlapping(rectangle2));
+
+        rectangle1 = new Rectangle(new Point(-5, 1), new Point(3, 4));
+        rectangle2 = new Rectangle(new Point(-2, -2), new Point(5, -1));
+        assertFalse(rectangle1.isOverlapping(rectangle2));
+
+        rectangle1 = new Rectangle(new Point(-2, 1), new Point(0, 3));
+        rectangle2 = new Rectangle(new Point(3, 1), new Point(5, 4));
+        assertFalse(rectangle1.isOverlapping(rectangle2));
+    }
+
+}

apache-avro/pom.xml

@@ -4,8 +4,9 @@
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
-    <artifactId>apache-avro-tutorial</artifactId>
+    <artifactId>apache-avro</artifactId>
     <version>0.0.1-SNAPSHOT</version>
+	<name>Apache Avro</version>
 
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

apache-cxf/README.md

@@ -3,3 +3,4 @@
 - [Apache CXF Support for RESTful Web Services](http://www.baeldung.com/apache-cxf-rest-api)
 - [A Guide to Apache CXF with Spring](http://www.baeldung.com/apache-cxf-with-spring)
 - [Introduction to Apache CXF](http://www.baeldung.com/introduction-to-apache-cxf)
+- [Server-Sent Events (SSE) In JAX-RS](https://www.baeldung.com/java-ee-jax-rs-sse)

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

@@ -20,7 +20,7 @@
     </properties>
 
     <build>
-        <finalName>${artifactId}</finalName>
+        <finalName>${project.artifactId}</finalName>
         <plugins>
             <plugin>
                 <groupId>net.wasdev.wlp.maven.plugins</groupId>

aws/.gitignore

@@ -1 +1,2 @@
 /target/
+.idea/

aws/src/main/java/com/baeldung/rds/AWSRDSService.java

@@ -0,0 +1,184 @@
+package com.baeldung.rds;
+
+import com.amazonaws.auth.AWSCredentialsProvider;
+import com.amazonaws.auth.AWSStaticCredentialsProvider;
+import com.amazonaws.auth.BasicAWSCredentials;
+import com.amazonaws.regions.Regions;
+import com.amazonaws.services.rds.AmazonRDS;
+import com.amazonaws.services.rds.AmazonRDSClientBuilder;
+import com.amazonaws.services.rds.model.*;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.sql.*;
+import java.util.List;
+import java.util.Properties;
+import java.util.UUID;
+import java.util.logging.Logger;
+
+public class AWSRDSService {
+
+
+    final static Logger logger = Logger.getLogger(AWSRDSService.class.getName());
+    private AWSCredentialsProvider credentials;
+    private AmazonRDS amazonRDS;
+    private String db_username;
+    private String db_password;
+    private String db_database;
+    private String db_hostname;
+
+    /*
+    * User access key and secret key must be set before execute any operation.
+    * Follow the link on how to get the user access and secret key
+    * https://aws.amazon.com/blogs/security/wheres-my-secret-access-key/
+    * **/
+    public AWSRDSService() throws IOException {
+        //Init RDS client with credentials and region.
+        credentials = new
+                AWSStaticCredentialsProvider(new
+                BasicAWSCredentials("<ACCESS_KEY>",
+                "<SECRET_KEY>"));
+        amazonRDS = AmazonRDSClientBuilder.standard().withCredentials(credentials)
+                .withRegion(Regions.AP_SOUTHEAST_2).build();
+        Properties prop = new Properties();
+        InputStream input = AWSRDSService.class.getClassLoader().getResourceAsStream("db.properties");
+        prop.load(input);
+        db_username = prop.getProperty("db_username");
+        db_password = prop.getProperty("db_password");
+        db_database = prop.getProperty("db_database");
+    }
+
+    public AWSRDSService(AmazonRDS amazonRDS){
+        this.amazonRDS = amazonRDS;
+    }
+
+    /**
+     * create the RDS instance.
+     * After instance creation, update the db_hostname with endpoint in db.properties.
+     * */
+
+    public String launchInstance() {
+
+        String identifier = "";
+        CreateDBInstanceRequest request = new CreateDBInstanceRequest();
+        // RDS instance name
+        request.setDBInstanceIdentifier("Sydney");
+        request.setEngine("postgres");
+        request.setMultiAZ(false);
+        request.setMasterUsername(db_username);
+        request.setMasterUserPassword(db_password);
+        request.setDBName(db_database);
+        request.setStorageType("gp2");
+        request.setAllocatedStorage(10);
+
+        DBInstance instance = amazonRDS.createDBInstance(request);
+
+        // Information about the new RDS instance
+        identifier = instance.getDBInstanceIdentifier();
+        String status = instance.getDBInstanceStatus();
+        Endpoint endpoint = instance.getEndpoint();
+        String endpoint_url = "Endpoint URL not available yet.";
+        if (endpoint != null) {
+            endpoint_url = endpoint.toString();
+        }
+        logger.info(identifier + "\t" + status);
+        logger.info(endpoint_url);
+
+        return identifier;
+
+    }
+
+    // Describe DB instances
+    public void listInstances() {
+        DescribeDBInstancesResult result = amazonRDS.describeDBInstances();
+        List<DBInstance> instances = result.getDBInstances();
+        for (DBInstance instance : instances) {
+            // Information about each RDS instance
+            String identifier = instance.getDBInstanceIdentifier();
+            String engine = instance.getEngine();
+            String status = instance.getDBInstanceStatus();
+            Endpoint endpoint = instance.getEndpoint();
+            String endpoint_url = "Endpoint URL not available yet.";
+            if (endpoint != null) {
+                endpoint_url = endpoint.toString();
+            }
+            logger.info(identifier + "\t" + engine + "\t" + status);
+            logger.info("\t" + endpoint_url);
+        }
+
+    }
+
+    //Delete RDS instance
+    public void terminateInstance(String identifier) {
+
+        DeleteDBInstanceRequest request = new DeleteDBInstanceRequest();
+        request.setDBInstanceIdentifier(identifier);
+        request.setSkipFinalSnapshot(true);
+
+        // Delete the RDS instance
+        DBInstance instance = amazonRDS.deleteDBInstance(request);
+
+        // Information about the RDS instance being deleted
+        String status = instance.getDBInstanceStatus();
+        Endpoint endpoint = instance.getEndpoint();
+        String endpoint_url = "Endpoint URL not available yet.";
+        if (endpoint != null) {
+            endpoint_url = endpoint.toString();
+        }
+
+        logger.info(identifier + "\t" + status);
+        logger.info(endpoint_url);
+
+    }
+
+
+    public void runJdbcTests() throws SQLException, IOException {
+
+        // Getting database properties from db.properties
+        Properties prop = new Properties();
+        InputStream input = AWSRDSService.class.getClassLoader().getResourceAsStream("db.properties");
+        prop.load(input);
+        db_hostname = prop.getProperty("db_hostname");
+        String jdbc_url = "jdbc:postgresql://" + db_hostname + ":5432/" + db_database;
+
+        // Create a connection using the JDBC driver
+        try (Connection conn = DriverManager.getConnection(jdbc_url, db_username, db_password)) {
+
+            // Create the test table if not exists
+            Statement statement = conn.createStatement();
+            String sql = "CREATE TABLE IF NOT EXISTS jdbc_test (id SERIAL PRIMARY KEY, content VARCHAR(80))";
+            statement.executeUpdate(sql);
+
+            // Do some INSERT
+            PreparedStatement preparedStatement = conn.prepareStatement("INSERT INTO jdbc_test (content) VALUES (?)");
+            String content = "" + UUID.randomUUID();
+            preparedStatement.setString(1, content);
+            preparedStatement.executeUpdate();
+            logger.info("INSERT: " + content);
+
+            // Do some SELECT
+            sql = "SELECT  * FROM jdbc_test";
+            ResultSet resultSet = statement.executeQuery(sql);
+            while (resultSet.next()) {
+                String count = resultSet.getString("content");
+                logger.info("Total Records: " + count);
+            }
+        }
+
+
+    }
+
+    public static void main(String[] args) throws IOException, SQLException {
+        AWSRDSService awsrdsService = new AWSRDSService();
+
+        String instanceName = awsrdsService.launchInstance();
+
+        //Add some wait for instance creation.
+
+        awsrdsService.listInstances();
+
+        awsrdsService.runJdbcTests();
+
+        awsrdsService.terminateInstance(instanceName);
+    }
+}

aws/src/main/resources/db.properties

@@ -0,0 +1,4 @@
+db_hostname=<RDS EndPoint>
+db_username=username
+db_password=password
+db_database=mydb

core-java-8/README.md

@@ -29,3 +29,6 @@
 - [Java 8 Unsigned Arithmetic Support](http://www.baeldung.com/java-unsigned-arithmetic)
 - [Generalized Target-Type Inference in Java](http://www.baeldung.com/java-generalized-target-type-inference)
 - [Overriding System Time for Testing in Java](http://www.baeldung.com/java-override-system-time)
+- [Set the Time Zone of a Date in Java](https://www.baeldung.com/java-set-date-time-zone)
+- [An Overview of Regular Expressions Performance in Java](https://www.baeldung.com/java-regex-performance)
+- [Java Primitives versus Objects](https://www.baeldung.com/java-primitives-vs-objects)

core-java-9/README.md

@@ -24,3 +24,5 @@
 - [Optional orElse Optional](http://www.baeldung.com/java-optional-or-else-optional)
 - [Java 9 java.lang.Module API](http://www.baeldung.com/java-9-module-api)
 - [Iterate Through a Range of Dates in Java](https://www.baeldung.com/java-iterate-date-range)
+- [Initialize a HashMap in Java](https://www.baeldung.com/java-initialize-hashmap)
+- [Java 9 Platform Logging API](https://www.baeldung.com/java-9-logging-api)

core-java-9/src/test/java/com/baeldung/java9/process/ProcessUnderstandingTest.java

@@ -48,7 +48,7 @@ class ProcessUnderstandingTest {
     }
 
     //@Test - windows specific
-    public void givenSubProcess_thenStartSuccessIsAlive() throws IOException {
+    public void givenSubProcess_whenStarted_thenStartSuccessIsAlive() throws IOException {
         ProcessBuilder builder = new ProcessBuilder("notepad.exe");
         assertTrue(builder.start().isAlive());
     }
@@ -75,7 +75,7 @@ class ProcessUnderstandingTest {
     }
 
     //@Test - windows specific
-    public void givenSubProcess_checkAlive() throws IOException, InterruptedException {
+    public void givenSubProcess_whenDestroyed_thenCheckIfAlive() throws IOException, InterruptedException {
         ProcessBuilder builder = new ProcessBuilder("notepad.exe");
         Process process = builder.start();
         Thread.sleep(10000);

core-java-collections/README.md

@@ -43,3 +43,9 @@
 - [An Introduction to Java.util.Hashtable Class](http://www.baeldung.com/java-hash-table)
 - [Copy a List to Another List in Java](http://www.baeldung.com/java-copy-list-to-another)
 - [Finding Max/Min of a List or Collection](http://www.baeldung.com/java-collection-min-max)
+- [Java Null-Safe Streams from Collections](https://www.baeldung.com/java-null-safe-streams-from-collections)
+- [Remove All Occurrences of a Specific Value from a List](https://www.baeldung.com/java-remove-value-from-list)
+- [Thread Safe LIFO Data Structure Implementations](https://www.baeldung.com/java-lifo-thread-safe)
+- [Collections.emptyList() vs. New List Instance](https://www.baeldung.com/java-collections-emptylist-new-list)
+- [Initialize a HashMap in Java](https://www.baeldung.com/java-initialize-hashmap)
+- [](https://www.baeldung.com/java-hashset-arraylist-contains-performance)

core-java-collections/src/main/java/com/baeldung/performance/ArrayListBenchmark.java

@@ -0,0 +1,77 @@
+package com.baeldung.performance;
+
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+import java.util.*;
+import java.util.concurrent.TimeUnit;
+
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
+@Warmup(iterations = 10)
+public class ArrayListBenchmark {
+
+    @State(Scope.Thread)
+    public static class MyState {
+
+        List<Employee> employeeList = new ArrayList<>();
+        //LinkedList<Employee> employeeList = new LinkedList<>();
+
+        long iterations = 100000;
+
+        Employee employee = new Employee(100L, "Harry");
+
+        int employeeIndex = -1;
+
+        @Setup(Level.Trial)
+        public void setUp() {
+            for (long i = 0; i < iterations; i++) {
+                employeeList.add(new Employee(i, "John"));
+            }
+
+            employeeList.add(employee);
+            employeeIndex = employeeList.indexOf(employee);
+        }
+    }
+
+    @Benchmark
+    public void testAddAt(ArrayListBenchmark.MyState state) {
+        state.employeeList.add((int) (state.iterations), new Employee(state.iterations, "John"));
+    }
+
+    @Benchmark
+    public boolean testContains(ArrayListBenchmark.MyState state) {
+        return state.employeeList.contains(state.employee);
+    }
+
+    @Benchmark
+    public int testIndexOf(ArrayListBenchmark.MyState state) {
+        return state.employeeList.indexOf(state.employee);
+    }
+
+    @Benchmark
+    public Employee testGet(ArrayListBenchmark.MyState state) {
+        return state.employeeList.get(state.employeeIndex);
+    }
+
+    @Benchmark
+    public boolean testRemove(ArrayListBenchmark.MyState state) {
+        return state.employeeList.remove(state.employee);
+    }
+
+//    @Benchmark
+//    public void testAdd(ArrayListBenchmark.MyState state) {
+//        state.employeeList.add(new Employee(state.iterations + 1, "John"));
+//    }
+
+    public static void main(String[] args) throws Exception {
+        Options options = new OptionsBuilder()
+                .include(ArrayListBenchmark.class.getSimpleName()).threads(1)
+                .forks(1).shouldFailOnError(true)
+                .shouldDoGC(true)
+                .jvmArgs("-server").build();
+        new Runner(options).run();
+    }
+}

core-java-collections/src/main/java/com/baeldung/performance/CopyOnWriteBenchmark.java

@@ -0,0 +1,78 @@
+package com.baeldung.performance;
+
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.concurrent.TimeUnit;
+
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
+@Warmup(iterations = 10)
+public class CopyOnWriteBenchmark {
+
+    @State(Scope.Thread)
+    public static class MyState {
+
+        CopyOnWriteArrayList<Employee> employeeList = new CopyOnWriteArrayList<>();
+
+        long iterations = 100000;
+
+        Employee employee = new Employee(100L, "Harry");
+
+        int employeeIndex = -1;
+
+        @Setup(Level.Trial)
+        public void setUp() {
+            for (long i = 0; i < iterations; i++) {
+                employeeList.add(new Employee(i, "John"));
+            }
+
+            employeeList.add(employee);
+
+            employeeIndex = employeeList.indexOf(employee);
+        }
+    }
+
+        @Benchmark
+    public void testAdd(CopyOnWriteBenchmark.MyState state) {
+            state.employeeList.add(new Employee(state.iterations + 1, "John"));
+    }
+
+    @Benchmark
+    public void testAddAt(CopyOnWriteBenchmark.MyState state) {
+        state.employeeList.add((int) (state.iterations), new Employee(state.iterations, "John"));
+    }
+
+    @Benchmark
+    public boolean testContains(CopyOnWriteBenchmark.MyState state) {
+        return state.employeeList.contains(state.employee);
+    }
+
+    @Benchmark
+    public int testIndexOf(CopyOnWriteBenchmark.MyState state) {
+        return state.employeeList.indexOf(state.employee);
+    }
+
+    @Benchmark
+    public Employee testGet(CopyOnWriteBenchmark.MyState state) {
+        return state.employeeList.get(state.employeeIndex);
+    }
+
+    @Benchmark
+    public boolean testRemove(CopyOnWriteBenchmark.MyState state) {
+        return state.employeeList.remove(state.employee);
+    }
+
+
+    public static void main(String[] args) throws Exception {
+        Options options = new OptionsBuilder()
+                .include(CopyOnWriteBenchmark.class.getSimpleName()).threads(1)
+                .forks(1).shouldFailOnError(true)
+                .shouldDoGC(true)
+                .jvmArgs("-server").build();
+        new Runner(options).run();
+    }
+}

core-java-collections/src/main/java/com/baeldung/performance/Employee.java

@@ -10,6 +10,22 @@ public class Employee {
         this.id = id;
     }
 
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;

core-java-collections/src/main/java/com/baeldung/performance/HashMapBenchmark.java

@@ -0,0 +1,73 @@
+package com.baeldung.performance;
+
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+import java.util.*;
+import java.util.concurrent.TimeUnit;
+
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
+@Warmup(iterations = 10)
+public class HashMapBenchmark {
+
+    @State(Scope.Thread)
+    public static class MyState {
+
+        Map<Long, Employee> employeeMap = new HashMap<>();
+        //LinkedHashMap<Long, Employee> employeeMap = new LinkedHashMap<>();
+        //IdentityHashMap<Long, Employee> employeeMap = new IdentityHashMap<>();
+        //WeakHashMap<Long, Employee> employeeMap = new WeakHashMap<>();
+        //ConcurrentHashMap<Long, Employee> employeeMap = new ConcurrentHashMap<>();
+        //ConcurrentSkipListMap<Long, Employee> employeeMap = new ConcurrentSkipListMap <>();
+
+        // TreeMap
+
+        long iterations = 100000;
+
+        Employee employee = new Employee(100L, "Harry");
+
+        int employeeIndex = -1;
+
+        @Setup(Level.Trial)
+        public void setUp() {
+            for (long i = 0; i < iterations; i++) {
+                employeeMap.put(i, new Employee(i, "John"));
+            }
+
+            //employeeMap.put(iterations, employee);
+        }
+    }
+
+    @Benchmark
+    public Employee testGet(HashMapBenchmark.MyState state) {
+        return state.employeeMap.get(state.iterations);
+    }
+
+    @Benchmark
+    public Employee testRemove(HashMapBenchmark.MyState state) {
+        return state.employeeMap.remove(state.iterations);
+    }
+
+    @Benchmark
+    public Employee testPut(HashMapBenchmark.MyState state) {
+        return state.employeeMap.put(state.employee.getId(), state.employee);
+    }
+
+    @Benchmark
+    public Boolean testContainsKey(HashMapBenchmark.MyState state) {
+        return state.employeeMap.containsKey(state.employee.getId());
+    }
+
+
+    public static void main(String[] args) throws Exception {
+        Options options = new OptionsBuilder()
+                .include(HashMapBenchmark.class.getSimpleName()).threads(1)
+                .forks(1).shouldFailOnError(true)
+                .shouldDoGC(true)
+                .jvmArgs("-server").build();
+        new Runner(options).run();
+    }
+}

core-java-collections/src/main/java/com/baeldung/performance/SetBenchMark.java

@@ -0,0 +1,66 @@
+package com.baeldung.performance;
+
+import org.openjdk.jmh.annotations.*;
+import org.openjdk.jmh.runner.Runner;
+import org.openjdk.jmh.runner.options.Options;
+import org.openjdk.jmh.runner.options.OptionsBuilder;
+
+import java.util.HashSet;
+import java.util.LinkedHashSet;
+import java.util.Set;
+import java.util.TreeSet;
+import java.util.concurrent.ConcurrentSkipListSet;
+import java.util.concurrent.TimeUnit;
+
+@BenchmarkMode(Mode.AverageTime)
+@OutputTimeUnit(TimeUnit.MICROSECONDS)
+@Warmup(iterations = 10)
+public class SetBenchMark {
+
+    @State(Scope.Thread)
+    public static class MyState {
+
+        //Set<Employee> employeeSet = new HashSet<>();
+        LinkedHashSet<Employee> employeeSet = new LinkedHashSet<>();
+        //ConcurrentSkipListSet<Employee> employeeSet = new ConcurrentSkipListSet <>();
+
+        // TreeSet 
+
+        long iterations = 1000;
+        Employee employee = new Employee(100L, "Harry");
+
+        @Setup(Level.Trial)
+        public void setUp() {
+            for (long i = 0; i < iterations; i++) {
+                employeeSet.add(new Employee(i, "John"));
+            }
+
+            //employeeSet.add(employee);
+        }
+    }
+
+    @Benchmark
+    public boolean testAdd(SetBenchMark.MyState state) {
+        return state.employeeSet.add(state.employee);
+    }
+
+    @Benchmark
+    public Boolean testContains(SetBenchMark.MyState state) {
+        return state.employeeSet.contains(state.employee);
+    }
+
+    @Benchmark
+    public boolean testRemove(SetBenchMark.MyState state) {
+        return state.employeeSet.remove(state.employee);
+    }
+
+
+    public static void main(String[] args) throws Exception {
+        Options options = new OptionsBuilder()
+                .include(SetBenchMark.class.getSimpleName()).threads(1)
+                .forks(1).shouldFailOnError(true)
+                .shouldDoGC(true)
+                .jvmArgs("-server").build();
+        new Runner(options).run();
+    }
+}

core-java-io/README.md

@@ -30,3 +30,4 @@
 - [Download a File From an URL in Java](http://www.baeldung.com/java-download-file)
 - [Create a Symbolic Link with Java](http://www.baeldung.com/java-symlink)
 - [Quick Use of FilenameFilter](http://www.baeldung.com/java-filename-filter)
+- [Initialize a HashMap in Java](https://www.baeldung.com/java-initialize-hashmap)

core-java-persistence/README.md

@@ -5,4 +5,5 @@
 ### Relevant Articles: 
 - [Introduction to JDBC](http://www.baeldung.com/java-jdbc)
 - [Batch Processing in JDBC](http://www.baeldung.com/jdbc-batch-processing)
-- [Introduction to the JDBC RowSet Interface in Java](http://www.baeldung.com/java-jdbc-rowset)
+- [Introduction to the JDBC RowSet Interface in Java](http://www.baeldung.com/java-jdbc-rowset)
+- [A Simple Guide to Connection Pooling in Java](https://www.baeldung.com/java-connection-pooling)

core-java/README.md

@@ -145,3 +145,9 @@
 - [Common Java Exceptions](http://www.baeldung.com/java-common-exceptions)
 - [Java Constructors vs Static Factory Methods](https://www.baeldung.com/java-constructors-vs-static-factory-methods)
 - [Differences Between Final, Finally and Finalize in Java](https://www.baeldung.com/java-final-finally-finalize)
+- [Static and Dynamic Binding in Java](https://www.baeldung.com/java-static-dynamic-binding)
+- [Java List Initialization in One Line](https://www.baeldung.com/java-init-list-one-line)
+- [Difference Between Throw and Throws in Java](https://www.baeldung.com/java-throw-throws)
+- [ClassCastException: Arrays$ArrayList cannot be cast to ArrayList](https://www.baeldung.com/java-classcastexception-arrays-arraylist)
+- [Throw Exception in Optional in Java 8](https://www.baeldung.com/java-optional-throw-exception)
+- [Add a Character to a String at a Given Position](https://www.baeldung.com/java-add-character-to-string)

core-java/src/main/java/com/baeldung/synthetic/BridgeMethodDemo.java

@@ -0,0 +1,23 @@
+package com.baeldung.synthetic;
+
+import java.util.Comparator;
+
+/**
+ * Class which contains a synthetic bridge method.
+ * 
+ * @author Donato Rimenti
+ *
+ */
+public class BridgeMethodDemo implements Comparator<Integer> {
+
+    /*
+     * (non-Javadoc)
+     * 
+     * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
+     */
+    @Override
+    public int compare(Integer o1, Integer o2) {
+        return 0;
+    }
+
+}

core-java/src/main/java/com/baeldung/synthetic/SyntheticConstructorDemo.java

@@ -0,0 +1,34 @@
+package com.baeldung.synthetic;
+
+/**
+ * Wrapper for a class which contains a synthetic constructor.
+ * 
+ * @author Donato Rimenti
+ *
+ */
+public class SyntheticConstructorDemo {
+
+    /**
+     * We need to instantiate the {@link NestedClass} using a private
+     * constructor from the enclosing instance in order to generate a synthetic
+     * constructor.
+     */
+    private NestedClass nestedClass = new NestedClass();
+
+    /**
+     * Class which contains a synthetic constructor.
+     * 
+     * @author Donato Rimenti
+     *
+     */
+    class NestedClass {
+
+        /**
+         * In order to generate a synthetic constructor, this class must have a
+         * private constructor.
+         */
+        private NestedClass() {
+        }
+    }
+
+}

core-java/src/main/java/com/baeldung/synthetic/SyntheticFieldDemo.java

@@ -0,0 +1,22 @@
+package com.baeldung.synthetic;
+
+/**
+ * Wrapper for a class which contains a synthetic field reference to the outer
+ * class.
+ * 
+ * @author Donato Rimenti
+ *
+ */
+public class SyntheticFieldDemo {
+
+    /**
+     * Class which contains a synthetic field reference to the outer class.
+     * 
+     * @author Donato Rimenti
+     *
+     */
+    class NestedClass {
+
+    }
+
+}

core-java/src/main/java/com/baeldung/synthetic/SyntheticMethodDemo.java

@@ -0,0 +1,48 @@
+package com.baeldung.synthetic;
+
+/**
+ * Wrapper for a class which contains two synthetic methods accessors to a
+ * private field.
+ * 
+ * @author Donato Rimenti
+ *
+ */
+public class SyntheticMethodDemo {
+
+    /**
+     * Class which contains two synthetic methods accessors to a private field.
+     * 
+     * @author Donato Rimenti
+     *
+     */
+    class NestedClass {
+
+        /**
+         * Field for which will be generated synthetic methods accessors. It's
+         * important that this field is private for this purpose.
+         */
+        private String nestedField;
+    }
+
+    /**
+     * Gets the private nested field. We need to read the nested field in order
+     * to generate the synthetic getter.
+     * 
+     * @return the {@link NestedClass#nestedField}
+     */
+    public String getNestedField() {
+        return new NestedClass().nestedField;
+    }
+
+    /**
+     * Sets the private nested field. We need to write the nested field in order
+     * to generate the synthetic setter.
+     * 
+     * @param nestedField
+     *            the {@link NestedClass#nestedField}
+     */
+    public void setNestedField(String nestedField) {
+        new NestedClass().nestedField = nestedField;
+    }
+
+}

core-java/src/test/java/com/baeldung/synthetic/SyntheticUnitTest.java

@@ -0,0 +1,99 @@
+package com.baeldung.synthetic;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Unit test for {@link SyntheticFieldDemo}, {@link SyntheticMethodDemo},
+ * {@link SyntheticConstructorDemo} and {@link BridgeMethodDemo} classes.
+ * 
+ * @author Donato Rimenti
+ *
+ */
+public class SyntheticUnitTest {
+
+    /**
+     * Tests that the {@link SyntheticMethodDemo.NestedClass} contains two synthetic
+     * methods.
+     */
+    @Test
+    public void givenSyntheticMethod_whenIsSinthetic_thenTrue() {
+        // Checks that the nested class contains exactly two synthetic methods.
+        Method[] methods = SyntheticMethodDemo.NestedClass.class.getDeclaredMethods();
+        Assert.assertEquals("This class should contain only two methods", 2, methods.length);
+
+        for (Method m : methods) {
+            System.out.println("Method: " + m.getName() + ", isSynthetic: " + m.isSynthetic());
+            Assert.assertTrue("All the methods of this class should be synthetic", m.isSynthetic());
+        }
+    }
+
+    /**
+     * Tests that {@link SyntheticConstructorDemo.NestedClass} contains a synthetic
+     * constructor.
+     */
+    @Test
+    public void givenSyntheticConstructor_whenIsSinthetic_thenTrue() {
+        // Checks that the nested class contains exactly a synthetic
+        // constructor.
+        int syntheticConstructors = 0;
+        Constructor<?>[] constructors = SyntheticConstructorDemo.NestedClass.class.getDeclaredConstructors();
+        Assert.assertEquals("This class should contain only two constructors", 2, constructors.length);
+
+        for (Constructor<?> c : constructors) {
+            System.out.println("Constructor: " + c.getName() + ", isSynthetic: " + c.isSynthetic());
+
+            // Counts the synthetic constructors.
+            if (c.isSynthetic()) {
+                syntheticConstructors++;
+            }
+        }
+
+        // Checks that there's exactly one synthetic constructor.
+        Assert.assertEquals(1, syntheticConstructors);
+    }
+
+    /**
+     * Tests that {@link SyntheticFieldDemo.NestedClass} contains a synthetic field.
+     */
+    @Test
+    public void givenSyntheticField_whenIsSinthetic_thenTrue() {
+        // This class should contain exactly one synthetic field.
+        Field[] fields = SyntheticFieldDemo.NestedClass.class.getDeclaredFields();
+        Assert.assertEquals("This class should contain only one field", 1, fields.length);
+
+        for (Field f : fields) {
+            System.out.println("Field: " + f.getName() + ", isSynthetic: " + f.isSynthetic());
+            Assert.assertTrue("All the fields of this class should be synthetic", f.isSynthetic());
+        }
+    }
+
+    /**
+     * Tests that {@link BridgeMethodDemo} contains a synthetic bridge method.
+     */
+    @Test
+    public void givenBridgeMethod_whenIsBridge_thenTrue() {
+        // This class should contain exactly one synthetic bridge method.
+        int syntheticMethods = 0;
+        Method[] methods = BridgeMethodDemo.class.getDeclaredMethods();
+        for (Method m : methods) {
+            System.out.println(
+                    "Method: " + m.getName() + ", isSynthetic: " + m.isSynthetic() + ", isBridge: " + m.isBridge());
+
+            // Counts the synthetic methods and checks that they are also bridge
+            // methods.
+            if (m.isSynthetic()) {
+                syntheticMethods++;
+                Assert.assertTrue("The synthetic method in this class should also be a bridge method", m.isBridge());
+            }
+        }
+        
+        // Checks that there's exactly one synthetic bridge method.
+        Assert.assertEquals("There should be exactly 1 synthetic bridge method in this class", 1, syntheticMethods);
+    }
+
+}

core-kotlin/README.md

@@ -38,3 +38,7 @@
 - [Reflection with Kotlin](http://www.baeldung.com/kotlin-reflection)
 - [Get a Random Number in Kotlin](http://www.baeldung.com/kotlin-random-number)
 - [Idiomatic Logging in Kotlin](http://www.baeldung.com/kotlin-logging)
+- [Kotlin Constructors](https://www.baeldung.com/kotlin-constructors)
+- [Creational Design Patterns in Kotlin: Builder](https://www.baeldung.com/kotlin-builder-pattern)
+- [Kotlin Nested and Inner Classes](https://www.baeldung.com/kotlin-inner-classes)
+- [Guide to the Kotlin Exposed Framework](https://www.baeldung.com/kotlin-exposed-persistence)

core-kotlin/pom.xml

@@ -87,6 +87,26 @@
             <artifactId>h2</artifactId>
             <version>${h2database.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.github.kittinunf.fuel</groupId>
+            <artifactId>fuel</artifactId>
+            <version>${fuel.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.github.kittinunf.fuel</groupId>
+            <artifactId>fuel-gson</artifactId>
+            <version>${fuel.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.github.kittinunf.fuel</groupId>
+            <artifactId>fuel-rxjava</artifactId>
+            <version>${fuel.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>com.github.kittinunf.fuel</groupId>
+            <artifactId>fuel-coroutines</artifactId>
+            <version>${fuel.version}</version>
+        </dependency>
     </dependencies>
 
     <properties>
@@ -100,6 +120,7 @@
         <assertj.version>3.10.0</assertj.version>
         <h2database.version>1.4.197</h2database.version>
         <exposed.version>0.10.4</exposed.version>
+        <fuel.version>1.15.0</fuel.version>
     </properties>
 
-</project>
+</project>

core-kotlin/src/main/kotlin/com/baeldung/fuel/Interceptors.kt

@@ -0,0 +1,11 @@
+package com.baeldung.fuel
+
+import com.github.kittinunf.fuel.core.Request
+
+fun tokenInterceptor() = {
+    next: (Request) -> Request ->
+    { req: Request ->
+        req.header(mapOf("Authorization" to "Bearer AbCdEf123456"))
+        next(req)
+    }
+}

core-kotlin/src/main/kotlin/com/baeldung/fuel/Post.kt

@@ -0,0 +1,15 @@
+package com.baeldung.fuel
+
+import com.github.kittinunf.fuel.core.ResponseDeserializable
+import com.google.gson.Gson
+
+data class Post(var userId:Int,
+                var id:Int,
+                var title:String,
+                var body:String){
+
+
+    class Deserializer : ResponseDeserializable<Array<Post>> {
+        override fun deserialize(content: String): Array<Post> = Gson().fromJson(content, Array<Post>::class.java)
+    }
+}

core-kotlin/src/main/kotlin/com/baeldung/fuel/PostRoutingAPI.kt

@@ -0,0 +1,42 @@
+package com.baeldung.fuel
+
+import com.github.kittinunf.fuel.core.Method
+import com.github.kittinunf.fuel.util.FuelRouting
+
+sealed class PostRoutingAPI : FuelRouting {
+
+    override val basePath = "https://jsonplaceholder.typicode.com"
+
+    class posts(val id: String, override val body: String?): PostRoutingAPI()
+
+    class comments(val postId: String, override val body: String?): PostRoutingAPI()
+
+    override val method: Method
+        get() {
+            return when(this) {
+                is PostRoutingAPI.posts -> Method.GET
+                is PostRoutingAPI.comments -> Method.GET
+            }
+        }
+
+    override val path: String
+        get() {
+            return when(this) {
+                is PostRoutingAPI.posts -> "/posts"
+                is PostRoutingAPI.comments -> "/comments"
+            }
+        }
+
+    override val params: List<Pair<String, Any?>>?
+        get() {
+            return when(this) {
+                is PostRoutingAPI.posts -> listOf("id" to this.id)
+                is PostRoutingAPI.comments -> listOf("postId" to this.postId)
+            }
+        }
+
+    override val headers: Map<String, String>?
+        get() {
+            return null
+        }
+}

core-kotlin/src/test/kotlin/com/baeldung/builder/BuilderPatternUnitTest.kt

@@ -93,6 +93,7 @@ internal class BuilderPatternUnitTest {
         Assertions.assertNull(foodOrder.fish)
     }
 
+
     @Test
     fun whenBuildingFoodOrderApplySettingValues_thenFieldsNotNull() {
 

core-kotlin/src/test/kotlin/com/baeldung/fuel/FuelHttpUnitTest.kt

@@ -0,0 +1,286 @@
+package com.baeldung.fuel
+
+import awaitObjectResult
+import awaitStringResponse
+import com.github.kittinunf.fuel.Fuel
+import com.github.kittinunf.fuel.core.FuelManager
+import com.github.kittinunf.fuel.core.Request
+import com.github.kittinunf.fuel.core.interceptors.cUrlLoggingRequestInterceptor
+import com.github.kittinunf.fuel.gson.responseObject
+import com.github.kittinunf.fuel.httpGet
+import com.github.kittinunf.fuel.rx.rx_object
+import com.google.gson.Gson
+import kotlinx.coroutines.experimental.runBlocking
+import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.Test
+import java.io.File
+import java.util.concurrent.CountDownLatch
+
+internal class FuelHttpUnitTest {
+
+    @Test
+    fun whenMakingAsyncHttpGetRequest_thenResponseNotNullAndErrorNullAndStatusCode200() {
+
+        val latch = CountDownLatch(1)
+
+        "http://httpbin.org/get".httpGet().response{
+            request, response, result ->
+
+            val (data, error) = result
+
+            Assertions.assertNull(error)
+            Assertions.assertNotNull(data)
+            Assertions.assertEquals(200,response.statusCode)
+
+            latch.countDown()
+        }
+
+        latch.await()
+
+    }
+
+    @Test
+    fun whenMakingSyncHttpGetRequest_thenResponseNotNullAndErrorNullAndStatusCode200() {
+
+        val (request, response, result) = "http://httpbin.org/get".httpGet().response()
+        val (data, error) = result
+
+        Assertions.assertNull(error)
+        Assertions.assertNotNull(data)
+        Assertions.assertEquals(200,response.statusCode)
+
+    }
+
+    @Test
+    fun whenMakingSyncHttpGetURLEncodedRequest_thenResponseNotNullAndErrorNullAndStatusCode200() {
+
+        val (request, response, result) =
+          "https://jsonplaceholder.typicode.com/posts"
+          .httpGet(listOf("id" to "1")).response()
+        val (data, error) = result
+
+        Assertions.assertNull(error)
+        Assertions.assertNotNull(data)
+        Assertions.assertEquals(200,response.statusCode)
+
+    }
+
+    @Test
+    fun whenMakingAsyncHttpPostRequest_thenResponseNotNullAndErrorNullAndStatusCode200() {
+
+        val latch = CountDownLatch(1)
+
+        Fuel.post("http://httpbin.org/post").response{
+            request, response, result ->
+
+            val (data, error) = result
+
+            Assertions.assertNull(error)
+            Assertions.assertNotNull(data)
+            Assertions.assertEquals(200,response.statusCode)
+
+            latch.countDown()
+        }
+
+        latch.await()
+
+    }
+
+    @Test
+    fun whenMakingSyncHttpPostRequest_thenResponseNotNullAndErrorNullAndStatusCode200() {
+
+        val (request, response, result) = Fuel.post("http://httpbin.org/post").response()
+        val (data, error) = result
+
+        Assertions.assertNull(error)
+        Assertions.assertNotNull(data)
+        Assertions.assertEquals(200,response.statusCode)
+    }
+
+    @Test
+    fun whenMakingSyncHttpPostRequestwithBody_thenResponseNotNullAndErrorNullAndStatusCode200() {
+
+        val (request, response, result) = Fuel.post("https://jsonplaceholder.typicode.com/posts")
+          .body("{ \"title\" : \"foo\",\"body\" : \"bar\",\"id\" : \"1\"}")
+          .response()
+
+        val (data, error) = result
+
+        Assertions.assertNull(error)
+        Assertions.assertNotNull(data)
+        Assertions.assertEquals(201,response.statusCode)
+    }
+
+    @Test
+    fun givenFuelInstance_whenMakingSyncHttpGetRequest_thenResponseNotNullAndErrorNullAndStatusCode200() {
+
+        FuelManager.instance.basePath = "http://httpbin.org"
+        FuelManager.instance.baseHeaders = mapOf("OS" to "macOS High Sierra")
+
+        FuelManager.instance.addRequestInterceptor(cUrlLoggingRequestInterceptor())
+        FuelManager.instance.addRequestInterceptor(tokenInterceptor())
+
+
+        val (request, response, result) = "/get"
+          .httpGet().response()
+        val (data, error) = result
+
+        Assertions.assertNull(error)
+        Assertions.assertNotNull(data)
+        Assertions.assertEquals(200,response.statusCode)
+    }
+
+    @Test
+    fun givenInterceptors_whenMakingSyncHttpGetRequest_thenResponseNotNullAndErrorNullAndStatusCode200() {
+
+        FuelManager.instance.basePath = "http://httpbin.org"
+        FuelManager.instance.addRequestInterceptor(cUrlLoggingRequestInterceptor())
+        FuelManager.instance.addRequestInterceptor(tokenInterceptor())
+
+        val (request, response, result) = "/get"
+                .httpGet().response()
+        val (data, error) = result
+
+        Assertions.assertNull(error)
+        Assertions.assertNotNull(data)
+        Assertions.assertEquals(200,response.statusCode)
+    }
+
+    @Test
+    fun whenDownloadFile_thenCreateFileResponseNotNullAndErrorNullAndStatusCode200() {
+
+        Fuel.download("http://httpbin.org/bytes/32768").destination { response, url ->
+            File.createTempFile("temp", ".tmp")
+        }.response{
+            request, response, result ->
+
+            val (data, error) = result
+            Assertions.assertNull(error)
+            Assertions.assertNotNull(data)
+            Assertions.assertEquals(200,response.statusCode)
+        }
+    }
+
+    @Test
+    fun whenDownloadFilewithProgressHandler_thenCreateFileResponseNotNullAndErrorNullAndStatusCode200() {
+
+        val (request, response, result) = Fuel.download("http://httpbin.org/bytes/327680")
+          .destination { response, url -> File.createTempFile("temp", ".tmp")
+        }.progress { readBytes, totalBytes ->
+            val progress = readBytes.toFloat() / totalBytes.toFloat()
+        }.response ()
+
+        val (data, error) = result
+        Assertions.assertNull(error)
+        Assertions.assertNotNull(data)
+        Assertions.assertEquals(200,response.statusCode)
+
+
+    }
+
+    @Test
+    fun whenMakeGetRequest_thenDeserializePostwithGson() {
+
+        val latch = CountDownLatch(1)
+
+        "https://jsonplaceholder.typicode.com/posts/1".httpGet().responseObject<Post> { _,_, result ->
+            val post = result.component1()
+            Assertions.assertEquals(1, post?.userId)
+            latch.countDown()
+        }
+
+        latch.await()
+
+    }
+
+    @Test
+    fun whenMakePOSTRequest_thenSerializePostwithGson() {
+
+        val post = Post(1,1, "Lorem", "Lorem Ipse dolor sit amet")
+
+        val (request, response, result) = Fuel.post("https://jsonplaceholder.typicode.com/posts")
+                .header("Content-Type" to "application/json")
+                .body(Gson().toJson(post).toString())
+                .response()
+
+        Assertions.assertEquals(201,response.statusCode)
+
+    }
+
+    @Test
+    fun whenMakeGETRequestWithRxJava_thenDeserializePostwithGson() {
+
+        val latch = CountDownLatch(1)
+
+
+        "https://jsonplaceholder.typicode.com/posts?id=1"
+                .httpGet().rx_object(Post.Deserializer()).subscribe{
+                    res, throwable ->
+
+                    val post = res.component1()
+                    Assertions.assertEquals(1, post?.get(0)?.userId)
+                    latch.countDown()
+                }
+
+        latch.await()
+
+    }
+
+    @Test
+    fun whenMakeGETRequestUsingCoroutines_thenResponseStatusCode200() {
+
+        runBlocking {
+            val (request, response, result) = Fuel.get("http://httpbin.org/get").awaitStringResponse()
+
+            result.fold({ data ->
+                Assertions.assertEquals(200, response.statusCode)
+
+            }, { error -> })
+        }
+
+    }
+
+    @Test
+    fun whenMakeGETRequestUsingCoroutines_thenDeserializeResponse() {
+
+
+        runBlocking {
+            Fuel.get("https://jsonplaceholder.typicode.com/posts?id=1").awaitObjectResult(Post.Deserializer())
+                    .fold({ data ->
+                        Assertions.assertEquals(1, data.get(0).userId)
+                    }, { error -> })
+        }
+
+    }
+
+    @Test
+    fun whenMakeGETPostRequestUsingRoutingAPI_thenDeserializeResponse() {
+
+        val latch = CountDownLatch(1)
+
+        Fuel.request(PostRoutingAPI.posts("1",null))
+          .responseObject(Post.Deserializer()) {
+              request, response, result ->
+              Assertions.assertEquals(1, result.component1()?.get(0)?.userId)
+              latch.countDown()
+          }
+
+        latch.await()
+    }
+
+    @Test
+    fun whenMakeGETCommentRequestUsingRoutingAPI_thenResponseStausCode200() {
+
+        val latch = CountDownLatch(1)
+
+        Fuel.request(PostRoutingAPI.comments("1",null))
+          .responseString { request, response, result ->
+            Assertions.assertEquals(200, response.statusCode)
+            latch.countDown()
+          }
+
+        latch.await()
+    }
+
+
+}

couchbase/pom.xml

@@ -3,11 +3,11 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
-    <artifactId>couchbase-sdk</artifactId>
+    <artifactId>couchbase</artifactId>
     <version>0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
     <name>couchbase</name>
-    <description>Couchbase SDK Tutorials</description>
+    <description>Couchbase Tutorials</description>
 
     <parent>
         <groupId>com.baeldung</groupId>

drools/pom.xml

@@ -48,12 +48,18 @@
             <artifactId>poi-ooxml</artifactId>
             <version>${apache-poi-version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.optaplanner</groupId>
+            <artifactId>optaplanner-core</artifactId>
+            <version>${opta-planner-version}</version>
+        </dependency>
     </dependencies>
 
     <properties>
         <http-component-version>4.4.6</http-component-version>
         <drools-version>7.4.1.Final</drools-version>
         <apache-poi-version>3.13</apache-poi-version>
+        <opta-planner-version>7.10.0.Final</opta-planner-version>
     </properties>
 
 </project>

drools/src/main/java/com/baeldung/drools/optaplanner/CourseSchedule.java

@@ -0,0 +1,63 @@
+package com.baeldung.drools.optaplanner;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.optaplanner.core.api.domain.solution.PlanningEntityCollectionProperty;
+import org.optaplanner.core.api.domain.solution.PlanningScore;
+import org.optaplanner.core.api.domain.solution.PlanningSolution;
+import org.optaplanner.core.api.domain.solution.drools.ProblemFactCollectionProperty;
+import org.optaplanner.core.api.domain.valuerange.ValueRangeProvider;
+import org.optaplanner.core.api.score.buildin.hardsoft.HardSoftScore;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+@PlanningSolution
+public class CourseSchedule {
+
+    Logger logger = LoggerFactory.getLogger("CourseSchedule");
+
+    private List<Integer> roomList;
+    private List<Integer> periodList;
+    private List<Lecture> lectureList;
+    private HardSoftScore score;
+
+    public CourseSchedule(){
+        roomList = new ArrayList<>();
+        periodList = new ArrayList<>();
+        lectureList = new ArrayList<>();
+    }
+
+    @ValueRangeProvider(id = "availableRooms")
+    @ProblemFactCollectionProperty
+    public List<Integer> getRoomList() {
+        return roomList;
+    }
+
+    @ValueRangeProvider(id = "availablePeriods")
+    @ProblemFactCollectionProperty
+    public List<Integer> getPeriodList() {
+        return periodList;
+    }
+
+    @PlanningEntityCollectionProperty
+    public List<Lecture> getLectureList() {
+        return lectureList;
+    }
+
+    @PlanningScore
+    public HardSoftScore getScore() {
+        return score;
+    }
+
+    public void setScore(HardSoftScore score) {
+        this.score = score;
+    }
+
+    public void printCourseSchedule() {
+        lectureList.stream()
+                .map(c -> "Lecture in Room " + c.getRoomNumber().toString() + " during Period " + c.getPeriod().toString())
+                .forEach(k -> logger.info(k));
+    }
+
+}

drools/src/main/java/com/baeldung/drools/optaplanner/Lecture.java

@@ -0,0 +1,30 @@
+package com.baeldung.drools.optaplanner;
+
+import org.optaplanner.core.api.domain.entity.PlanningEntity;
+import org.optaplanner.core.api.domain.variable.PlanningVariable;
+
+@PlanningEntity
+public class Lecture {
+
+    private Integer roomNumber;
+    private Integer period;
+
+    @PlanningVariable(valueRangeProviderRefs = {"availablePeriods"})
+    public Integer getPeriod() {
+        return period;
+    }
+
+    @PlanningVariable(valueRangeProviderRefs = {"availableRooms"})
+    public Integer getRoomNumber() {
+        return roomNumber;
+    }
+
+    public void setPeriod(Integer period) {
+        this.period = period;
+    }
+
+    public void setRoomNumber(Integer roomNumber) {
+        this.roomNumber = roomNumber;
+    }
+
+}

drools/src/main/java/com/baeldung/drools/optaplanner/ScoreCalculator.java

@@ -0,0 +1,32 @@
+package com.baeldung.drools.optaplanner;
+
+import java.util.HashSet;
+
+import org.optaplanner.core.api.score.Score;
+import org.optaplanner.core.api.score.buildin.hardsoft.HardSoftScore;
+import org.optaplanner.core.impl.score.director.easy.EasyScoreCalculator;
+
+public class ScoreCalculator implements EasyScoreCalculator<CourseSchedule> {
+
+    @Override
+    public Score calculateScore(CourseSchedule courseSchedule) {
+        int hardScore = 0;
+        int softScore = 0;
+
+        HashSet<String> occupiedRooms = new HashSet<>();
+        for (Lecture lecture : courseSchedule.getLectureList()) {
+            if(lecture.getPeriod() != null && lecture.getRoomNumber() != null) {
+                String roomInUse = lecture.getPeriod().toString() + ":" + lecture.getRoomNumber().toString();
+                if (occupiedRooms.contains(roomInUse)) {
+                    hardScore += -1;
+                } else {
+                    occupiedRooms.add(roomInUse);
+                }
+            } else {
+                hardScore += -1;
+            }
+        }
+
+        return HardSoftScore.valueOf(hardScore, softScore);
+    }
+}

drools/src/main/resources/courseSchedule.drl

@@ -0,0 +1,14 @@
+package com.baeldung.drools.optaplanner
+
+import com.baeldung.drools.optaplanner.Lecture;
+import org.optaplanner.core.api.score.buildin.hardsoft.HardSoftScoreHolder;
+
+global HardSoftScoreHolder scoreHolder;
+
+rule "noNullRoomPeriod"
+    when
+        Lecture( roomNumber == null );
+        Lecture( period == null );
+    then
+        scoreHolder.addHardConstraintMatch(kcontext, -1);
+end

drools/src/main/resources/courseScheduleSolverConfigDrools.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<solver>
+    <scanAnnotatedClasses/>
+
+    <scoreDirectorFactory>
+        <scoreDrl>courseSchedule.drl</scoreDrl>
+    </scoreDirectorFactory>
+
+    <termination>
+        <secondsSpentLimit>10</secondsSpentLimit>
+    </termination>
+</solver>

drools/src/main/resources/courseScheduleSolverConfiguration.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<solver>
+    <scanAnnotatedClasses/>
+
+    <scoreDirectorFactory>
+        <easyScoreCalculatorClass>com.baeldung.drools.optaplanner.ScoreCalculator</easyScoreCalculatorClass>
+    </scoreDirectorFactory>
+
+    <termination>
+        <secondsSpentLimit>10</secondsSpentLimit>
+    </termination>
+</solver>

drools/src/test/java/com/baeldung/drools/optaplanner/OptaPlannerUnitTest.java

@@ -0,0 +1,49 @@
+package com.baeldung.drools.optaplanner;
+
+import java.util.Arrays;
+
+import org.junit.Assert;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.optaplanner.core.api.solver.Solver;
+import org.optaplanner.core.api.solver.SolverFactory;
+
+public class OptaPlannerUnitTest {
+
+    static CourseSchedule unsolvedCourseSchedule;
+
+    @BeforeAll
+    public static void setUp() {
+
+        unsolvedCourseSchedule = new CourseSchedule();
+
+        for(int i = 0; i < 10; i++){
+            unsolvedCourseSchedule.getLectureList().add(new Lecture());
+        }
+
+        unsolvedCourseSchedule.getPeriodList().addAll(Arrays.asList(new Integer[] { 1, 2, 3 }));
+        unsolvedCourseSchedule.getRoomList().addAll(Arrays.asList(new Integer[] { 1, 2 }));
+    }
+
+    @Test
+    public void test_whenCustomJavaSolver() {
+
+        SolverFactory<CourseSchedule> solverFactory = SolverFactory.createFromXmlResource("courseScheduleSolverConfiguration.xml");
+        Solver<CourseSchedule> solver = solverFactory.buildSolver();
+        CourseSchedule solvedCourseSchedule = solver.solve(unsolvedCourseSchedule);
+
+        Assert.assertNotNull(solvedCourseSchedule.getScore());
+        Assert.assertEquals(-4, solvedCourseSchedule.getScore().getHardScore());
+    }
+
+    @Test
+    public void test_whenDroolsSolver() {
+
+        SolverFactory<CourseSchedule> solverFactory = SolverFactory.createFromXmlResource("courseScheduleSolverConfigDrools.xml");
+        Solver<CourseSchedule> solver = solverFactory.buildSolver();
+        CourseSchedule solvedCourseSchedule = solver.solve(unsolvedCourseSchedule);
+
+        Assert.assertNotNull(solvedCourseSchedule.getScore());
+        Assert.assertEquals(0, solvedCourseSchedule.getScore().getHardScore());
+    }
+}

ejb/ejb-client/pom.xml

@@ -16,7 +16,6 @@
             <groupId>org.wildfly</groupId>
             <artifactId>wildfly-ejb-client-bom</artifactId>
             <type>pom</type>
-            <scope>import</scope>
         </dependency>
         <dependency>
             <groupId>com.baeldung.ejb</groupId>

ejb/pom.xml

@@ -17,7 +17,6 @@
 
     <modules>
         <module>ejb-remote</module>
-        <module>ejb-client</module>
         <module>ejb-session-beans</module>
     </modules>
 

ejb/wildfly/pom.xml

@@ -2,9 +2,10 @@
          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.wildfly</groupId>
-    <artifactId>wildfly-example</artifactId>
+    <artifactId>wildfly</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>pom</packaging>
+	<name>wildfly</name>
 
     <parent>
         <groupId>com.baeldung.ejb</groupId>

ejb/wildfly/wildfly-mdb/pom.xml

@@ -1,8 +1,9 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <artifactId>widlfly-mdb</artifactId>
-
+    <artifactId>wildfly-mdb</artifactId>
+	<name>wildfly-mdb</name>
+	
     <parent>
         <groupId>com.baeldung.wildfly</groupId>
         <artifactId>wildfly-example</artifactId>

enterprise-patterns/README.md

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

enterprise-patterns/intercepting-filter-pattern/src/main/java/com/baeldung/enterprise/patterns/front/controller/filters/AuditFilter.java

@@ -1,25 +0,0 @@
-package com.baeldung.enterprise.patterns.front.controller.filters;
-
-import javax.servlet.FilterChain;
-import javax.servlet.ServletException;
-import javax.servlet.ServletRequest;
-import javax.servlet.ServletResponse;
-import javax.servlet.http.HttpServletRequest;
-import javax.servlet.http.HttpSession;
-import java.io.IOException;
-
-public class AuditFilter extends BaseFilter {
-    @Override
-    public void doFilter(
-      ServletRequest request,
-      ServletResponse response,
-      FilterChain chain
-    ) throws IOException, ServletException {
-        HttpServletRequest httpServletRequest = (HttpServletRequest) request;
-        HttpSession session = httpServletRequest.getSession(false);
-        if (session != null && session.getAttribute("username") != null) {
-            request.setAttribute("username", session.getAttribute("username"));
-        }
-        chain.doFilter(request, response);
-    }
-}

enterprise-patterns/intercepting-filter-pattern/src/main/java/com/baeldung/enterprise/patterns/front/controller/filters/VisitorCounterFilter.java

@@ -1,23 +0,0 @@
-package com.baeldung.enterprise.patterns.front.controller.filters;
-
-import javax.servlet.FilterChain;
-import javax.servlet.ServletException;
-import javax.servlet.ServletRequest;
-import javax.servlet.ServletResponse;
-import javax.servlet.annotation.WebFilter;
-import java.io.IOException;
-
-@WebFilter(servletNames = "front-controller")
-public class VisitorCounterFilter extends BaseFilter {
-    private int counter;
-
-    @Override
-    public void doFilter(
-      ServletRequest request,
-      ServletResponse response,
-      FilterChain chain
-    ) throws IOException, ServletException {
-        request.setAttribute("counter", ++counter);
-        chain.doFilter(request, response);
-    }
-}

enterprise-patterns/pom.xml

@@ -1,19 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung.enterprise.patterns</groupId>
-    <artifactId>enterprise-patterns-parent</artifactId>
-    <packaging>pom</packaging>
-
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
-    </parent>
-
-    <modules>
-        <module>spring-dispatcher-servlet</module>
-    </modules>
-
-</project>

feign/pom.xml

@@ -3,7 +3,8 @@
     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.feign</groupId>
-    <artifactId>feign-client</artifactId>
+    <artifactId>feign</artifactId>
+	<name>feign</name>
 
     <parent>
         <groupId>com.baeldung</groupId>

google-web-toolkit/pom.xml

@@ -6,10 +6,11 @@
 	<!-- POM file generated with GWT webAppCreator -->
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>com.baeldung</groupId>
-	<artifactId>google_web_toolkit</artifactId>
+	<artifactId>google-web-toolkit</artifactId>
 	<packaging>war</packaging>
 	<version>1.0-SNAPSHOT</version>
-
+	<name>google-web-toolkit</name>
+	
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>

grpc/pom.xml

@@ -1,11 +1,11 @@
 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
-    <groupId>grpc</groupId>
-    <artifactId>grpc-demo</artifactId>
+    <artifactId>grpc</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
-
+	<name>grpc</name>
+	
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>parent-modules</artifactId>

gson/README.md

@@ -7,3 +7,4 @@
 - [Gson Deserialization Cookbook](http://www.baeldung.com/gson-deserialization-guide)
 - [Jackson vs Gson](http://www.baeldung.com/jackson-vs-gson)
 - [Exclude Fields from Serialization in Gson](http://www.baeldung.com/gson-exclude-fields-serialization)
+- [Save Data to a JSON File with Gson](https://www.baeldung.com/gson-save-file)

guava/README.md

@@ -33,3 +33,4 @@
 - [Using Guava CountingOutputStream](http://www.baeldung.com/guava-counting-outputstream)
 - [Hamcrest Text Matchers](http://www.baeldung.com/hamcrest-text-matchers)
 - [Quick Guide to the Guava RateLimiter](http://www.baeldung.com/guava-rate-limiter)
+- [Initialize a HashMap in Java](https://www.baeldung.com/java-initialize-hashmap)

guest/remote-debugging/pom.xml

@@ -3,9 +3,10 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.stackify</groupId>
-    <artifactId>java-remote-debugging</artifactId>
+    <artifactId>remote-debugging</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>war</packaging>
+	<name>remote-debugging</name>
 
     <parent>
         <groupId>org.springframework.boot</groupId>

hazelcast/README.md

@@ -1,2 +1,3 @@
 ### Relevant Articles:
 - [Guide to Hazelcast with Java](http://www.baeldung.com/java-hazelcast)
+- [Introduction to Hazelcast Jet](https://www.baeldung.com/hazelcast-jet)

hibernate5/README.md

@@ -13,3 +13,4 @@
 - [Pessimistic Locking in JPA](http://www.baeldung.com/jpa-pessimistic-locking)
 - [Bootstrapping JPA Programmatically in Java](http://www.baeldung.com/java-bootstrap-jpa)
 - [Optimistic Locking in JPA](http://www.baeldung.com/jpa-optimistic-locking)
+- [Hibernate Entity Lifecycle](https://www.baeldung.com/hibernate-entity-lifecycle)

intelliJ/README.md

@@ -0,0 +1,3 @@
+### Relevant Articles: 
+
+- [Writing IntelliJ IDEA Plugins](https://www.baeldung.com/intellij-new-custom-plugin)

java-streams/README.md

@@ -12,3 +12,4 @@
 - [Iterable to Stream in Java](http://www.baeldung.com/java-iterable-to-stream)
 - [How to Iterate Over a Stream With Indices](http://www.baeldung.com/java-stream-indices)
 - [Primitive Type Streams in Java 8](http://www.baeldung.com/java-8-primitive-streams)
+- [Stream Ordering in Java](https://www.baeldung.com/java-stream-ordering)

java-strings/README.md

@@ -24,4 +24,5 @@
 - [Check If a String Is Numeric in Java](http://www.baeldung.com/java-check-string-number)
 - [Why Use char[] Array Over a String for Storing Passwords in Java?](http://www.baeldung.com/java-storing-passwords)
 - [Convert a String to Title Case](http://www.baeldung.com/java-string-title-case)
-- [Compact Strings in Java 9](http://www.baeldung.com/java-9-compact-string)
+- [Compact Strings in Java 9](http://www.baeldung.com/java-9-compact-string)
+- [Java Check a String for Lowercase/Uppercase Letter, Special Character and Digit](https://www.baeldung.com/java-lowercase-uppercase-special-character-digit-regex)

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

@@ -1,8 +1,6 @@
 package com.baeldung.string;
 
-import static org.hamcrest.CoreMatchers.containsString;
-import static org.hamcrest.CoreMatchers.not;
-import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertEquals;
 
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -12,35 +10,28 @@ import org.junit.Test;
 import com.vdurmont.emoji.EmojiParser;
 
 public class RemovingEmojiFromStringUnitTest {
-    String text = "la conférence, commencera à 10 heures 😅 ✿";
+    String text = "la conférence, commencera à 10 heures 😅";
     String regex = "[^\\p{L}\\p{N}\\p{P}\\p{Z}]";
 
     @Test
     public void whenRemoveEmojiUsingLibrary_thenSuccess() {
         String result = EmojiParser.removeAllEmojis(text);
         System.out.println(result);
-        assertThat(result, not(containsString("😅")));
-        assertThat(result, containsString("à"));
-        assertThat(result, containsString("la"));
-        assertThat(result, containsString("10"));
+        assertEquals(result, "la conférence, commencera à 10 heures ");
     }
     
     @Test
     public void whenReplaceEmojiUsingLibrary_thenSuccess() {
         String result = EmojiParser.parseToAliases(text);
         System.out.println(result);
-        assertThat(result, not(containsString("😅")));
-        assertThat(result, containsString("sweat_smile"));
+        assertEquals(result, "la conférence, commencera à 10 heures :sweat_smile:");
     }
 
     @Test
     public void whenRemoveEmojiUsingRegex_thenSuccess() {
         String result = text.replaceAll(regex, "");
         System.out.println(result);
-        assertThat(result, not(containsString("😅")));
-        assertThat(result, containsString("à"));
-        assertThat(result, containsString("la"));
-        assertThat(result, containsString("10"));
+        assertEquals(result, "la conférence, commencera à 10 heures ");
     }
 
     @Test
@@ -50,29 +41,20 @@ public class RemovingEmojiFromStringUnitTest {
         
         String result = matcher.replaceAll("");
         System.out.println(result);
-        assertThat(result, not(containsString("😅")));
-        assertThat(result, containsString("à"));
-        assertThat(result, containsString("la"));
-        assertThat(result, containsString("10"));
+        assertEquals(result, "la conférence, commencera à 10 heures ");
     }
 
     @Test
     public void whenRemoveEmojiUsingCodepoints_thenSuccess() {
         String result = text.replaceAll("[\\x{0001f300}-\\x{0001f64f}]|[\\x{0001f680}-\\x{0001f6ff}]", "");
         System.out.println(result);
-        assertThat(result, not(containsString("😅")));
-        assertThat(result, containsString("à"));
-        assertThat(result, containsString("la"));
-        assertThat(result, containsString("10"));
+        assertEquals(result, "la conférence, commencera à 10 heures ");
     }
 
     @Test
     public void whenRemoveEmojiUsingUnicode_thenSuccess() {
         String result = text.replaceAll("[\ud83c\udf00-\ud83d\ude4f]|[\ud83d\ude80-\ud83d\udeff]", "");
         System.out.println(result);
-        assertThat(result, not(containsString("😅")));
-        assertThat(result, containsString("à"));
-        assertThat(result, containsString("la"));
-        assertThat(result, containsString("10"));
+        assertEquals(result, "la conférence, commencera à 10 heures ");
     }
 }

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

@@ -0,0 +1,62 @@
+package com.baeldung.string;
+
+import java.util.Scanner;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.apache.commons.lang3.StringUtils;
+import org.junit.Assert;
+import org.junit.Test;
+
+public class SubstringUnitTest {
+
+    String text = "Julia Evans was born on 25-09-1984. She is currently living in the USA (United States of America).";
+
+    @Test
+    public void givenAString_whenUsedStringUtils_ShouldReturnProperSubstring() {
+        Assert.assertEquals("United States of America", StringUtils.substringBetween(text, "(", ")"));
+        Assert.assertEquals("the USA (United States of America).", StringUtils.substringAfter(text, "living in "));
+        Assert.assertEquals("Julia Evans", StringUtils.substringBefore(text, " was born"));
+    }
+
+    @Test
+    public void givenAString_whenUsedScanner_ShouldReturnProperSubstring() {
+        try (Scanner scanner = new Scanner(text)) {
+            scanner.useDelimiter("\\.");
+            Assert.assertEquals("Julia Evans was born on 25-09-1984", scanner.next());
+        }
+    }
+
+    @Test
+    public void givenAString_whenUsedSplit_ShouldReturnProperSubstring() {
+        String[] sentences = text.split("\\.");
+        Assert.assertEquals("Julia Evans was born on 25-09-1984", sentences[0]);
+    }
+
+    @Test
+    public void givenAString_whenUsedRegex_ShouldReturnProperSubstring() {
+        Pattern pattern = Pattern.compile("\\d{2}\\-\\d{2}-\\d{4}");
+        Matcher matcher = pattern.matcher(text);
+
+        if (matcher.find()) {
+            Assert.assertEquals("25-09-1984", matcher.group());
+        }
+    }
+
+    @Test
+    public void givenAString_whenUsedSubSequence_ShouldReturnProperSubstring() {
+        Assert.assertEquals("USA (United States of America)", text.subSequence(67, text.length() - 1));
+    }
+
+    @Test
+    public void givenAString_whenUsedSubstring_ShouldReturnProperSubstring() {
+        Assert.assertEquals("USA (United States of America).", text.substring(67));
+        Assert.assertEquals("USA (United States of America)", text.substring(67, text.length() - 1));
+    }
+
+    @Test
+    public void givenAString_whenUsedSubstringWithIndexOf_ShouldReturnProperSubstring() {
+        Assert.assertEquals("United States of America", text.substring(text.indexOf('(') + 1, text.indexOf(')')));
+    }
+
+}

javaxval/bin/.gitignore

@@ -1,6 +0,0 @@
-.classpath
-.project
-.settings/
-target/
-
-

javaxval/bin/pom.xml

@@ -1,44 +0,0 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
-    <artifactId>javaxval</artifactId>
-    <version>0.1-SNAPSHOT</version>
-
-
-    <dependencies>
-
-        <dependency>
-            <groupId>javax.validation</groupId>
-            <artifactId>validation-api</artifactId>
-            <version>1.1.0.Final</version>
-        </dependency>
-
-        <dependency>
-            <groupId>org.hibernate</groupId>
-            <artifactId>hibernate-validator</artifactId>
-            <version>5.2.1.Final</version>
-        </dependency>
-
-        <dependency>
-            <groupId>org.hibernate</groupId>
-            <artifactId>hibernate-validator-annotation-processor</artifactId>
-            <version>5.2.1.Final</version>
-        </dependency>
-
-        <dependency>
-            <groupId>javax.el</groupId>
-            <artifactId>javax.el-api</artifactId>
-            <version>2.2.4</version>
-        </dependency>
-
-        <dependency>
-            <groupId>org.glassfish.web</groupId>
-            <artifactId>javax.el</artifactId>
-            <version>2.2.4</version>
-        </dependency>
-
-    </dependencies>
-
-
-</project>

jee-7/pom.xml

@@ -384,10 +384,6 @@
         </profile>
     </profiles>
 
-    <prerequisites>
-        <maven>${maven.min.version}</maven>
-    </prerequisites>
-
     <repositories>
         <repository>
             <id>bintray-mvc-spec-maven</id>

jersey/README.md

@@ -1 +1,2 @@
-- [Jersey Filters and Interceptors] (http://www.baeldung.com/jersey-filters-interceptors)
+- [Jersey Filters and Interceptors](http://www.baeldung.com/jersey-filters-interceptors)
+- [Jersey MVC Support](https://www.baeldung.com/jersey-mvc)

jhipster/jhipster-microservice/car-app/pom.xml

@@ -10,10 +10,10 @@
         <relativePath>../../../parent-boot-1</relativePath>
     </parent>
     <groupId>com.car.app</groupId>
-    <artifactId>carapp</artifactId>
+    <artifactId>car-app</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>war</packaging>
-    <name>Carapp</name>
+    <name>car-app</name>
 
     <prerequisites>
         <maven>${maven.version}</maven>

jhipster/jhipster-microservice/dealer-app/pom.xml

@@ -3,10 +3,10 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.dealer.app</groupId>
-    <artifactId>dealerapp</artifactId>
+    <artifactId>dealer-app</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>war</packaging>
-    <name>Dealerapp</name>
+    <name>dealer-app</name>
 
     <parent>
         <artifactId>parent-boot-1</artifactId>

jhipster/jhipster-microservice/gateway-app/pom.xml

@@ -3,10 +3,10 @@
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.gateway</groupId>
-    <artifactId>gateway</artifactId>
+    <artifactId>gateway-app</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>war</packaging>
-    <name>Gateway</name>
+    <name>gateway-app</name>
 
     <parent>
         <artifactId>parent-boot-1</artifactId>

jhipster/jhipster-monolithic/pom.xml

@@ -412,6 +412,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-eclipse-plugin</artifactId>
+                <version>${maven-eclipse-plugin.version}</version>
                 <configuration>
                     <downloadSources>true</downloadSources>
                     <downloadJavadocs>true</downloadJavadocs>
@@ -879,10 +880,6 @@
         </profile>
     </profiles>
 
-    <prerequisites>
-        <maven>${maven.version}</maven>
-    </prerequisites>
-
     <properties>
         <argLine>-Djava.security.egd=file:/dev/./urandom -Xmx256m</argLine>
         <assertj.version>3.6.2</assertj.version>
@@ -909,6 +906,7 @@
         <mapstruct.version>1.1.0.Final</mapstruct.version>
         <maven-enforcer-plugin.version>1.4.1</maven-enforcer-plugin.version>
         <maven-resources-plugin.version>3.0.1</maven-resources-plugin.version>
+        <maven-eclipse-plugin.version>2.10</maven-eclipse-plugin.version>
         <maven.build.timestamp.format>yyyyMMddHHmmss</maven.build.timestamp.format>
         <maven.version>3.0.0</maven.version>
         <metrics-spring.version>3.1.3</metrics-spring.version>

jjwt/pom.xml

@@ -3,10 +3,10 @@
     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>io.jsonwebtoken</groupId>
-    <artifactId>jjwtfun</artifactId>
+    <artifactId>jjwt</artifactId>
     <version>0.0.1-SNAPSHOT</version>
     <packaging>jar</packaging>
-    <name>jjwtfun</name>
+    <name>jjwt</name>
     <description>Exercising the JJWT</description>
 
     <parent>

jnosql/jnosql-artemis/pom.xml

@@ -19,7 +19,7 @@
     </properties>
 
     <build>
-        <finalName>${artifactId}</finalName>
+        <finalName>${project.artifactId}</finalName>
         <plugins>
             <plugin>
                 <groupId>net.wasdev.wlp.maven.plugins</groupId>

jsf/pom.xml

@@ -36,11 +36,6 @@
             <version>${jstl.version}</version>
         </dependency>
         <!-- Spring -->
-        <dependency>
-            <groupId>org.springframework</groupId>
-            <artifactId>spring-web</artifactId>
-            <version>${org.springframework.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.springframework</groupId>
             <artifactId>spring-webmvc</artifactId>

json/README.md

@@ -9,3 +9,4 @@
 - [Introduction to JsonPath](http://www.baeldung.com/guide-to-jayway-jsonpath)
 - [Introduction to JSON-Java (org.json)](http://www.baeldung.com/java-org-json)
 - [Overview of JSON Pointer](https://www.baeldung.com/json-pointer)
+- [Introduction to the JSON Binding API (JSR 367) in Java](http://www.baeldung.com/java-json-binding-api)

json/pom.xml

@@ -33,7 +33,11 @@
             <artifactId>json</artifactId>
             <version>20171018</version>
         </dependency>
-        
+		<dependency>
+            <groupId>javax.json.bind</groupId>
+            <artifactId>javax.json.bind-api</artifactId>
+            <version>${jsonb-api.version}</version>
+        </dependency>
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
@@ -46,12 +50,26 @@
             <artifactId>javax.json</artifactId>
             <version>1.1.2</version>
         </dependency>
-        
+		<dependency>
+			<groupId>org.eclipse</groupId>
+			<artifactId>yasson</artifactId>
+			<version>${yasson.version}</version>
+        </dependency>
+		<!-- utils -->
+        <dependency>
+            <groupId>org.apache.commons</groupId>
+            <artifactId>commons-collections4</artifactId>
+            <version>${commons-collections4.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 
     <properties>
         <everit.json.schema.version>1.4.1</everit.json.schema.version>
         <fastjson.version>1.2.21</fastjson.version>
+        <jsonb-api.version>1.0</jsonb-api.version>
+        <commons-collections4.version>4.1</commons-collections4.version>
+        <yasson.version>1.0.1</yasson.version>
     </properties>
 
 </project>

json/src/test/java/com/baeldung/jsonb/JsonbUnitTest.java

@@ -18,8 +18,9 @@ import org.apache.commons.collections4.ListUtils;
 import org.junit.Test;
 
 import com.baeldung.adapter.PersonAdapter;
+import com.baeldung.jsonb.Person;
 
-public class JsonbTest {
+public class JsonbUnitTest {
 
     @Test
     public void givenPersonList_whenSerializeWithJsonb_thenGetPersonJsonArray() {

jsonb/.gitignore

@@ -1,12 +0,0 @@
-#folders#
-.idea
-/target
-/neoDb*
-/data
-/src/main/webapp/WEB-INF/classes
-*/META-INF/*
-
-# Packaged files #
-*.jar
-*.war
-*.ear

jsonb/README.md

@@ -1,4 +0,0 @@
-## JSON B
-
-## Relevant articles:
-- [Introduction to the JSON Binding API (JSR 367) in Java](http://www.baeldung.com/java-json-binding-api)

jsonb/pom.xml

@@ -1,101 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <modelVersion>4.0.0</modelVersion>
-    <groupId>com.baeldung</groupId>
-    <artifactId>json-b</artifactId>
-    <version>0.0.1-SNAPSHOT</version>
-    <packaging>jar</packaging>
-    <name>json-b</name>
-    <description>json-b sample project</description>
-
-    <parent>
-        <groupId>com.baeldung</groupId>
-        <artifactId>parent-modules</artifactId>
-        <version>1.0.0-SNAPSHOT</version>
-    </parent>
-
-    <dependencies>
-        <dependency>
-            <groupId>javax.json.bind</groupId>
-            <artifactId>javax.json.bind-api</artifactId>
-            <version>${jsonb-api.version}</version>
-        </dependency>
-        <!-- utils -->
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-collections4</artifactId>
-            <version>${commons-collections4.version}</version>
-            <scope>test</scope>
-        </dependency>
-
-        <dependency>
-            <groupId>org.junit.jupiter</groupId>
-            <artifactId>junit-jupiter-api</artifactId>
-            <version>${junit.jupiter.version}</version>
-        </dependency>
-        <dependency>
-            <groupId>org.junit.platform</groupId>
-            <artifactId>junit-platform-surefire-provider</artifactId>
-            <version>${junit.platform.version}</version>
-            <scope>test</scope>
-        </dependency>
-        <dependency>
-            <groupId>org.junit.platform</groupId>
-            <artifactId>junit-platform-runner</artifactId>
-            <version>${junit.platform.version}</version>
-            <scope>test</scope>
-        </dependency>
-    </dependencies>
-
-    <profiles>
-        <profile>
-            <id>yasson</id>
-            <activation>
-                <activeByDefault>true</activeByDefault>
-            </activation>
-            <dependencies>
-                <!-- Dependencies for Yasson -->
-                <dependency>
-                    <groupId>org.eclipse</groupId>
-                    <artifactId>yasson</artifactId>
-                    <version>${yasson.version}</version>
-                </dependency>
-                <dependency>
-                    <groupId>org.glassfish</groupId>
-                    <artifactId>javax.json</artifactId>
-                    <version>${javax.json.version}</version>
-                </dependency>
-            </dependencies>
-        </profile>
-        <profile>
-            <id>johnzon</id>
-            <dependencies>
-                <!-- Dependencies for Johnzon -->
-                <dependency>
-                    <groupId>org.apache.geronimo.specs</groupId>
-                    <artifactId>geronimo-json_1.1_spec</artifactId>
-                    <version>${geronimo-json_1.1_spec.version}</version>
-                </dependency>
-                <dependency>
-                    <groupId>org.apache.johnzon</groupId>
-                    <artifactId>johnzon-jsonb</artifactId>
-                    <version>${johnzon.version}</version>
-                </dependency>
-            </dependencies>
-        </profile>
-    </profiles>
-
-    <properties>
-        <maven.compiler.source>1.8</maven.compiler.source>
-        <maven.compiler.target>1.8</maven.compiler.target>
-        <junit.platform.version>1.0.0</junit.platform.version>
-        <jsonb-api.version>1.0</jsonb-api.version>
-        <johnzon.version>1.1.3</johnzon.version>
-        <geronimo-json_1.1_spec.version>1.0</geronimo-json_1.1_spec.version>
-        <yasson.version>1.0.1</yasson.version>
-        <javax.json.version>1.1.2</javax.json.version>
-        <commons-collections4.version>4.1</commons-collections4.version>
-    </properties>
-
-</project>

jta/pom.xml

@@ -0,0 +1,88 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>com.baeldung</groupId>
+    <artifactId>jta-demo</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <packaging>jar</packaging>
+
+    <description>JEE JTA demo</description>
+
+    <parent>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-parent</artifactId>
+        <version>2.0.4.RELEASE</version>
+        <relativePath/>
+    </parent>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
+        <java.version>1.8</java.version>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-jta-bitronix</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-jdbc</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.hsqldb</groupId>
+            <artifactId>hsqldb</artifactId>
+            <version>2.4.1</version>
+        </dependency>
+    </dependencies>
+
+    <profiles>
+        <profile>
+            <id>autoconfiguration</id>
+            <build>
+                <plugins>
+                    <plugin>
+                        <groupId>org.apache.maven.plugins</groupId>
+                        <artifactId>maven-surefire-plugin</artifactId>
+                        <executions>
+                            <execution>
+                                <phase>integration-test</phase>
+                                <goals>
+                                    <goal>test</goal>
+                                </goals>
+                                <configuration>
+                                    <excludes>
+                                        <exclude>**/*LiveTest.java</exclude>
+                                        <exclude>**/*IntegrationTest.java</exclude>
+                                        <exclude>**/*IntTest.java</exclude>
+                                    </excludes>
+                                    <includes>
+                                        <include>**/AutoconfigurationTest.java</include>
+                                    </includes>
+                                </configuration>
+                            </execution>
+                        </executions>
+                        <configuration>
+                            <systemPropertyVariables>
+                                <test.mime>json</test.mime>
+                            </systemPropertyVariables>
+                        </configuration>
+                    </plugin>
+                </plugins>
+            </build>
+        </profile>
+    </profiles>
+</project>

jta/src/main/java/com/baeldung/jtademo/JtaDemoApplication.java

@@ -0,0 +1,48 @@
+package com.baeldung.jtademo;
+
+import org.hsqldb.jdbc.pool.JDBCXADataSource;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.jta.bitronix.BitronixXADataSourceWrapper;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+import javax.sql.DataSource;
+
+@EnableAutoConfiguration
+@EnableTransactionManagement
+@Configuration
+@ComponentScan
+public class JtaDemoApplication {
+
+    @Bean("dataSourceAccount")
+    public DataSource dataSource() throws Exception {
+        return createHsqlXADatasource("jdbc:hsqldb:mem:accountDb");
+    }
+
+    @Bean("dataSourceAudit")
+    public DataSource dataSourceAudit() throws Exception {
+        return createHsqlXADatasource("jdbc:hsqldb:mem:auditDb");
+    }
+
+    private DataSource createHsqlXADatasource(String connectionUrl) throws Exception {
+        JDBCXADataSource dataSource = new JDBCXADataSource();
+        dataSource.setUrl(connectionUrl);
+        dataSource.setUser("sa");
+        BitronixXADataSourceWrapper wrapper = new BitronixXADataSourceWrapper();
+        return wrapper.wrapDataSource(dataSource);
+    }
+
+    @Bean("jdbcTemplateAccount")
+    public JdbcTemplate jdbcTemplate(@Qualifier("dataSourceAccount") DataSource dataSource) {
+        return new JdbcTemplate(dataSource);
+    }
+
+    @Bean("jdbcTemplateAudit")
+    public JdbcTemplate jdbcTemplateAudit(@Qualifier("dataSourceAudit") DataSource dataSource) {
+        return new JdbcTemplate(dataSource);
+    }
+}

jta/src/main/java/com/baeldung/jtademo/dto/TransferLog.java

@@ -0,0 +1,27 @@
+package com.baeldung.jtademo.dto;
+
+import java.math.BigDecimal;
+
+public class TransferLog {
+    private String fromAccountId;
+    private String toAccountId;
+    private BigDecimal amount;
+
+    public TransferLog(String fromAccountId, String toAccountId, BigDecimal amount) {
+        this.fromAccountId = fromAccountId;
+        this.toAccountId = toAccountId;
+        this.amount = amount;
+    }
+
+    public String getFromAccountId() {
+        return fromAccountId;
+    }
+
+    public String getToAccountId() {
+        return toAccountId;
+    }
+
+    public BigDecimal getAmount() {
+        return amount;
+    }
+}

jta/src/main/java/com/baeldung/jtademo/services/AuditService.java

@@ -0,0 +1,33 @@
+package com.baeldung.jtademo.services;
+
+import com.baeldung.jtademo.dto.TransferLog;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.core.ResultSetExtractor;
+import org.springframework.stereotype.Service;
+
+import java.math.BigDecimal;
+
+@Service
+public class AuditService {
+
+    final JdbcTemplate jdbcTemplate;
+
+    @Autowired
+    public AuditService(@Qualifier("jdbcTemplateAudit") JdbcTemplate jdbcTemplate) {
+        this.jdbcTemplate = jdbcTemplate;
+    }
+
+    public void log(String fromAccount, String toAccount, BigDecimal amount) {
+        jdbcTemplate.update("insert into AUDIT_LOG(FROM_ACCOUNT, TO_ACCOUNT, AMOUNT) values ?,?,?", fromAccount, toAccount, amount);
+    }
+
+    public TransferLog lastTransferLog() {
+        return jdbcTemplate.query("select FROM_ACCOUNT,TO_ACCOUNT,AMOUNT from AUDIT_LOG order by ID desc", (ResultSetExtractor<TransferLog>) (rs) -> {
+            if (!rs.next())
+                return null;
+            return new TransferLog(rs.getString(1), rs.getString(2), BigDecimal.valueOf(rs.getDouble(3)));
+        });
+    }
+}

jta/src/main/java/com/baeldung/jtademo/services/BankAccountService.java

@@ -0,0 +1,32 @@
+package com.baeldung.jtademo.services;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.core.ResultSetExtractor;
+import org.springframework.stereotype.Service;
+
+import java.math.BigDecimal;
+
+@Service
+public class BankAccountService {
+
+    final JdbcTemplate jdbcTemplate;
+
+    @Autowired
+    public BankAccountService(@Qualifier("jdbcTemplateAccount") JdbcTemplate jdbcTemplate) {
+        this.jdbcTemplate = jdbcTemplate;
+    }
+
+    public void transfer(String fromAccountId, String toAccountId, BigDecimal amount) {
+        jdbcTemplate.update("update ACCOUNT set BALANCE=BALANCE-? where ID=?", amount, fromAccountId);
+        jdbcTemplate.update("update ACCOUNT set BALANCE=BALANCE+? where ID=?", amount, toAccountId);
+    }
+
+    public BigDecimal balanceOf(String accountId) {
+        return jdbcTemplate.query("select BALANCE from ACCOUNT where ID=?", new Object[] { accountId }, (ResultSetExtractor<BigDecimal>) (rs) -> {
+            rs.next();
+            return new BigDecimal(rs.getDouble(1));
+        });
+    }
+}

jta/src/main/java/com/baeldung/jtademo/services/TellerService.java

@@ -0,0 +1,45 @@
+package com.baeldung.jtademo.services;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import javax.transaction.Transactional;
+import javax.transaction.UserTransaction;
+import java.math.BigDecimal;
+
+@Service
+public class TellerService {
+    private final BankAccountService bankAccountService;
+    private final AuditService auditService;
+    private final UserTransaction userTransaction;
+
+    @Autowired
+    public TellerService(BankAccountService bankAccountService, AuditService auditService, UserTransaction userTransaction) {
+        this.bankAccountService = bankAccountService;
+        this.auditService = auditService;
+        this.userTransaction = userTransaction;
+    }
+
+    @Transactional
+    public void executeTransfer(String fromAccontId, String toAccountId, BigDecimal amount) {
+        bankAccountService.transfer(fromAccontId, toAccountId, amount);
+        auditService.log(fromAccontId, toAccountId, amount);
+        BigDecimal balance = bankAccountService.balanceOf(fromAccontId);
+        if (balance.compareTo(BigDecimal.ZERO) <= 0) {
+            throw new RuntimeException("Insufficient fund.");
+        }
+    }
+
+    public void executeTransferProgrammaticTx(String fromAccontId, String toAccountId, BigDecimal amount) throws Exception {
+        userTransaction.begin();
+        bankAccountService.transfer(fromAccontId, toAccountId, amount);
+        auditService.log(fromAccontId, toAccountId, amount);
+        BigDecimal balance = bankAccountService.balanceOf(fromAccontId);
+        if (balance.compareTo(BigDecimal.ZERO) <= 0) {
+            userTransaction.rollback();
+            throw new RuntimeException("Insufficient fund.");
+        } else {
+            userTransaction.commit();
+        }
+    }
+}

jta/src/main/java/com/baeldung/jtademo/services/TestHelper.java

@@ -0,0 +1,43 @@
+package com.baeldung.jtademo.services;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.core.io.DefaultResourceLoader;
+import org.springframework.core.io.Resource;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.jdbc.datasource.init.ScriptUtils;
+import org.springframework.stereotype.Component;
+
+import javax.sql.DataSource;
+import java.sql.Connection;
+import java.sql.SQLException;
+
+@Component
+public class TestHelper {
+    final JdbcTemplate jdbcTemplateAccount;
+
+    final JdbcTemplate jdbcTemplateAudit;
+
+    @Autowired
+    public TestHelper(@Qualifier("jdbcTemplateAccount") JdbcTemplate jdbcTemplateAccount, @Qualifier("jdbcTemplateAudit") JdbcTemplate jdbcTemplateAudit) {
+        this.jdbcTemplateAccount = jdbcTemplateAccount;
+        this.jdbcTemplateAudit = jdbcTemplateAudit;
+    }
+
+    public void runAccountDbInit() throws SQLException {
+        runScript("account.sql", jdbcTemplateAccount.getDataSource());
+    }
+
+    public void runAuditDbInit() throws SQLException {
+        runScript("audit.sql", jdbcTemplateAudit.getDataSource());
+    }
+
+    private void runScript(String scriptName, DataSource dataSouorce) throws SQLException {
+        DefaultResourceLoader resourceLoader = new DefaultResourceLoader();
+        Resource script = resourceLoader.getResource(scriptName);
+        try (Connection con = dataSouorce.getConnection()) {
+            ScriptUtils.executeSqlScript(con, script);
+        }
+    }
+
+}

jta/src/main/resources/account.sql

@@ -0,0 +1,9 @@
+DROP SCHEMA PUBLIC CASCADE;
+
+create table ACCOUNT (
+ID char(8) PRIMARY KEY,
+BALANCE NUMERIC(28,10)
+);
+
+insert into ACCOUNT(ID, BALANCE) values ('a0000001', 1000);
+insert into ACCOUNT(ID, BALANCE) values ('a0000002', 2000);

jta/src/main/resources/audit.sql

@@ -0,0 +1,8 @@
+DROP SCHEMA PUBLIC CASCADE;
+
+create table AUDIT_LOG (
+ID INTEGER IDENTITY PRIMARY KEY,
+FROM_ACCOUNT varchar(8),
+TO_ACCOUNT varchar(8),
+AMOUNT numeric(28,10)
+);

jta/src/test/java/com/baeldung/jtademo/JtaDemoUnitTest.java

@@ -0,0 +1,91 @@
+package com.baeldung.jtademo;
+
+import com.baeldung.jtademo.dto.TransferLog;
+import com.baeldung.jtademo.services.AuditService;
+import com.baeldung.jtademo.services.BankAccountService;
+import com.baeldung.jtademo.services.TellerService;
+import com.baeldung.jtademo.services.TestHelper;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import java.math.BigDecimal;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(classes = JtaDemoApplication.class)
+public class JtaDemoUnitTest {
+    @Autowired
+    TestHelper testHelper;
+
+    @Autowired
+    TellerService tellerService;
+
+    @Autowired
+    BankAccountService accountService;
+
+    @Autowired
+    AuditService auditService;
+
+    @Before
+    public void beforeTest() throws Exception {
+        testHelper.runAuditDbInit();
+        testHelper.runAccountDbInit();
+    }
+
+    @Test
+    public void givenAnnotationTx_whenNoException_thenAllCommitted() throws Exception {
+        tellerService.executeTransfer("a0000001", "a0000002", BigDecimal.valueOf(500));
+
+        assertThat(accountService.balanceOf("a0000001")).isEqualByComparingTo(BigDecimal.valueOf(500));
+        assertThat(accountService.balanceOf("a0000002")).isEqualByComparingTo(BigDecimal.valueOf(2500));
+
+        TransferLog lastTransferLog = auditService.lastTransferLog();
+        assertThat(lastTransferLog).isNotNull();
+        assertThat(lastTransferLog.getFromAccountId()).isEqualTo("a0000001");
+        assertThat(lastTransferLog.getToAccountId()).isEqualTo("a0000002");
+        assertThat(lastTransferLog.getAmount()).isEqualByComparingTo(BigDecimal.valueOf(500));
+    }
+
+    @Test
+    public void givenAnnotationTx_whenException_thenAllRolledBack() throws Exception {
+        assertThatThrownBy(() -> {
+            tellerService.executeTransfer("a0000002", "a0000001", BigDecimal.valueOf(100000));
+        }).hasMessage("Insufficient fund.");
+
+        assertThat(accountService.balanceOf("a0000001")).isEqualByComparingTo(BigDecimal.valueOf(1000));
+        assertThat(accountService.balanceOf("a0000002")).isEqualByComparingTo(BigDecimal.valueOf(2000));
+        assertThat(auditService.lastTransferLog()).isNull();
+    }
+
+    @Test
+    public void givenProgrammaticTx_whenCommit_thenAllCommitted() throws Exception {
+        tellerService.executeTransferProgrammaticTx("a0000001", "a0000002", BigDecimal.valueOf(500));
+
+        BigDecimal result = accountService.balanceOf("a0000001");
+        assertThat(accountService.balanceOf("a0000001")).isEqualByComparingTo(BigDecimal.valueOf(500));
+        assertThat(accountService.balanceOf("a0000002")).isEqualByComparingTo(BigDecimal.valueOf(2500));
+
+        TransferLog lastTransferLog = auditService.lastTransferLog();
+        assertThat(lastTransferLog).isNotNull();
+        assertThat(lastTransferLog.getFromAccountId()).isEqualTo("a0000001");
+        assertThat(lastTransferLog.getToAccountId()).isEqualTo("a0000002");
+        assertThat(lastTransferLog.getAmount()).isEqualByComparingTo(BigDecimal.valueOf(500));
+    }
+
+    @Test
+    public void givenProgrammaticTx_whenRollback_thenAllRolledBack() throws Exception {
+        assertThatThrownBy(() -> {
+            tellerService.executeTransferProgrammaticTx("a0000002", "a0000001", BigDecimal.valueOf(100000));
+        }).hasMessage("Insufficient fund.");
+
+        assertThat(accountService.balanceOf("a0000001")).isEqualByComparingTo(BigDecimal.valueOf(1000));
+        assertThat(accountService.balanceOf("a0000002")).isEqualByComparingTo(BigDecimal.valueOf(2000));
+        assertThat(auditService.lastTransferLog()).isNull();
+    }
+}

jws/pom.xml

@@ -13,20 +13,23 @@
         <version>1.0.0-SNAPSHOT</version>
     </parent>
 
+	<repositories>
+	    <repository>
+	        <id>OpenNMS Repository</id>
+	        <url>http://repo.opennms.org/maven2/</url>
+	    </repository>
+	</repositories>
+
     <dependencies>
         <dependency>
-            <groupId>javax.jnlp</groupId>
+            <groupId>javax.samples.jnlp</groupId>
             <artifactId>jnlp-servlet</artifactId>
             <version>${jnlp-servlet.version}</version>
-            <scope>system</scope>
-            <systemPath>${project.basedir}/java-core-samples-lib/jnlp-servlet.jar</systemPath>
         </dependency>
         <dependency>
-            <groupId>javax.jnlp</groupId>
-            <artifactId>jardiff</artifactId>
-            <version>${jardiff.version}</version>
-            <scope>system</scope>
-            <systemPath>${project.basedir}/java-core-samples-lib/jardiff.jar</systemPath>
+            <groupId>javax.samples.jnlp</groupId>
+            <artifactId>jnlp-jardiff</artifactId>
+            <version>${jnlp-jardiff.version}</version>
         </dependency>
     </dependencies>
 
@@ -81,8 +84,8 @@
     <properties>
         <maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
         <maven-war-plugin.version>3.0.0</maven-war-plugin.version>
-        <jardiff.version>7.0</jardiff.version>
-        <jnlp-servlet.version>7.0</jnlp-servlet.version>
+        <jnlp-jardiff.version>1.6.0</jnlp-jardiff.version>
+        <jnlp-servlet.version>1.6.0</jnlp-servlet.version>
     </properties>
 
 </project>

libraries-data/README.md

@@ -10,4 +10,4 @@
 - [A Guide to Apache Ignite](http://www.baeldung.com/apache-ignite)
 - [Apache Ignite with Spring Data](http://www.baeldung.com/apache-ignite-spring-data)
 - [Guide to JMapper](https://www.baeldung.com/jmapper)
-- [A Guide to Apache Crunch](https://www.baeldung.com/crunch)
+- [A Guide to Apache Crunch](https://www.baeldung.com/apache-crunch)

libraries-server/README.md

@@ -6,4 +6,4 @@
 - [Programatically Create, Configure, and Run a Tomcat Server](http://www.baeldung.com/tomcat-programmatic-setup)
 - [Creating and Configuring Jetty 9 Server in Java](http://www.baeldung.com/jetty-java-programmatic)
 - [Testing Netty with EmbeddedChannel](http://www.baeldung.com/testing-netty-embedded-channel)
-
+- [MQTT Client in Java](https://www.baeldung.com/java-mqtt-client)

libraries/pom.xml

@@ -154,6 +154,17 @@
             <artifactId>commons-dbutils</artifactId>
             <version>${commons.dbutils.version}</version>
         </dependency>
+        <dependency>
+            <groupId>org.apache.flink</groupId>
+            <artifactId>flink-connector-kafka-0.11_2.11</artifactId>
+            <version>${flink.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.flink</groupId>
+            <artifactId>flink-streaming-java_2.11</artifactId>
+            <version>${flink.version}</version>
+        </dependency>
+
         <dependency>
             <groupId>org.apache.flink</groupId>
             <artifactId>flink-core</artifactId>
@@ -178,7 +189,7 @@
         </dependency>
         <dependency>
             <groupId>org.apache.flink</groupId>
-            <artifactId>flink-test-utils_2.10</artifactId>
+            <artifactId>flink-test-utils_2.11</artifactId>
             <version>${flink.version}</version>
             <scope>test</scope>
         </dependency>
@@ -228,6 +239,11 @@
             <artifactId>jackson-databind</artifactId>
             <version>${jackson.version}</version>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.datatype</groupId>
+            <artifactId>jackson-datatype-jsr310</artifactId>
+            <version>${jackson.version}</version>
+        </dependency>
         <!-- JDO -->
         <dependency>
             <groupId>org.datanucleus</groupId>
@@ -700,11 +716,6 @@
             <artifactId>resilience4j-timelimiter</artifactId>
             <version>${resilience4j.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.apache.commons</groupId>
-            <artifactId>commons-math3</artifactId>
-            <version>${common-math3-version}</version>
-        </dependency>
         <dependency>
             <groupId>org.knowm.xchart</groupId>
             <artifactId>xchart</artifactId>
@@ -902,7 +913,7 @@
 
         <httpclient.version>4.5.3</httpclient.version>
         <commons.io.version>2.5</commons.io.version>
-        <flink.version>1.2.0</flink.version>
+        <flink.version>1.5.0</flink.version>
         <jackson.version>2.8.5</jackson.version>
         <neuroph.version>2.92</neuroph.version>
         <serenity.version>1.9.26</serenity.version>
@@ -948,7 +959,6 @@
         <jctools.version>2.1.2</jctools.version>
         <typesafe-akka.version>2.5.11</typesafe-akka.version>
         <resilience4j.version>0.12.1</resilience4j.version>
-        <common-math3-version>3.6.1</common-math3-version>
         <xchart-version>3.5.2</xchart-version>
         <commons-net.version>3.6</commons-net.version>
         <mockftpserver.version>2.7.1</mockftpserver.version>