BAEL-1517: Resolve merge conflicts

2018-02-11 10:45:48 +02:00 · 2018-02-11 10:45:48 +02:00 · aa4392972c
parent febfb466a6 d935985ec1
commit aa4392972c
118 changed files with 3666 additions and 194 deletions
--- a/.gitignore
+++ b/.gitignore
@ -43,3 +43,4 @@ spring-call-getters-using-reflection/.mvn/wrapper/maven-wrapper.properties
 spring-check-if-a-property-is-null/.mvn/wrapper/maven-wrapper.properties
 *.springBeans

+20171220-JMeter.csv
--- a/algorithms/src/main/java/com/baeldung/algorithms/maze/solver/BFSMazeSolver.java
+++ b/algorithms/src/main/java/com/baeldung/algorithms/maze/solver/BFSMazeSolver.java
@ -0,0 +1,52 @@
+package com.baeldung.algorithms.maze.solver;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+public class BFSMazeSolver {
+    private static final int[][] DIRECTIONS = { { 0, 1 }, { 1, 0 }, { 0, -1 }, { -1, 0 } };
+
+    public List<Coordinate> solve(Maze maze) {
+        LinkedList<Coordinate> nextToVisit = new LinkedList<>();
+        Coordinate start = maze.getEntry();
+        nextToVisit.add(start);
+
+        while (!nextToVisit.isEmpty()) {
+            Coordinate cur = nextToVisit.remove();
+
+            if (!maze.isValidLocation(cur.getX(), cur.getY()) || maze.isExplored(cur.getX(), cur.getY())) {
+                continue;
+            }
+
+            if (maze.isWall(cur.getX(), cur.getY())) {
+                maze.setVisited(cur.getX(), cur.getY(), true);
+                continue;
+            }
+
+            if (maze.isExit(cur.getX(), cur.getY())) {
+                return backtrackPath(cur);
+            }
+
+            for (int[] direction : DIRECTIONS) {
+                Coordinate coordinate = new Coordinate(cur.getX() + direction[0], cur.getY() + direction[1], cur);
+                nextToVisit.add(coordinate);
+                maze.setVisited(cur.getX(), cur.getY(), true);
+            }
+        }
+        return Collections.emptyList();
+    }
+
+    private List<Coordinate> backtrackPath(Coordinate cur) {
+        List<Coordinate> path = new ArrayList<>();
+        Coordinate iter = cur;
+
+        while (iter != null) {
+            path.add(iter);
+            iter = iter.parent;
+        }
+
+        return path;
+    }
+}
--- a/algorithms/src/main/java/com/baeldung/algorithms/maze/solver/Coordinate.java
+++ b/algorithms/src/main/java/com/baeldung/algorithms/maze/solver/Coordinate.java
@ -0,0 +1,31 @@
+package com.baeldung.algorithms.maze.solver;
+
+public class Coordinate {
+    int x;
+    int y;
+    Coordinate parent;
+
+    public Coordinate(int x, int y) {
+        this.x = x;
+        this.y = y;
+        this.parent = null;
+    }
+
+    public Coordinate(int x, int y, Coordinate parent) {
+        this.x = x;
+        this.y = y;
+        this.parent = parent;
+    }
+
+    int getX() {
+        return x;
+    }
+
+    int getY() {
+        return y;
+    }
+
+    Coordinate getParent() {
+        return parent;
+    }
+}
--- a/algorithms/src/main/java/com/baeldung/algorithms/maze/solver/DFSMazeSolver.java
+++ b/algorithms/src/main/java/com/baeldung/algorithms/maze/solver/DFSMazeSolver.java
@ -0,0 +1,48 @@
+package com.baeldung.algorithms.maze.solver;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class DFSMazeSolver {
+    private static final int[][] DIRECTIONS = { { 0, 1 }, { 1, 0 }, { 0, -1 }, { -1, 0 } };
+
+    public List<Coordinate> solve(Maze maze) {
+        List<Coordinate> path = new ArrayList<>();
+        if (explore(maze, maze.getEntry()
+            .getX(),
+            maze.getEntry()
+                .getY(),
+            path)) {
+            return path;
+        }
+        return Collections.emptyList();
+    }
+
+    private boolean explore(Maze maze, int row, int col, List<Coordinate> path) {
+        if (!maze.isValidLocation(row, col) || maze.isWall(row, col) || maze.isExplored(row, col)) {
+            return false;
+        }
+
+        path.add(new Coordinate(row, col));
+        maze.setVisited(row, col, true);
+
+        if (maze.isExit(row, col)) {
+            return true;
+        }
+
+        for (int[] direction : DIRECTIONS) {
+            Coordinate coordinate = getNextCoordinate(row, col, direction[0], direction[1]);
+            if (explore(maze, coordinate.getX(), coordinate.getY(), path)) {
+                return true;
+            }
+        }
+
+        path.remove(path.size() - 1);
+        return false;
+    }
+
+    private Coordinate getNextCoordinate(int row, int col, int i, int j) {
+        return new Coordinate(row + i, col + j);
+    }
+}
--- a/algorithms/src/main/java/com/baeldung/algorithms/maze/solver/Maze.java
+++ b/algorithms/src/main/java/com/baeldung/algorithms/maze/solver/Maze.java
@ -0,0 +1,141 @@
+package com.baeldung.algorithms.maze.solver;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Scanner;
+
+public class Maze {
+    private static final int ROAD = 0;
+    private static final int WALL = 1;
+    private static final int START = 2;
+    private static final int EXIT = 3;
+    private static final int PATH = 4;
+
+    private int[][] maze;
+    private boolean[][] visited;
+    private Coordinate start;
+    private Coordinate end;
+
+    public Maze(File maze) throws FileNotFoundException {
+        String fileText = "";
+        try (Scanner input = new Scanner(maze)) {
+            while (input.hasNextLine()) {
+                fileText += input.nextLine() + "\n";
+            }
+        }
+        initializeMaze(fileText);
+    }
+
+    private void initializeMaze(String text) {
+        if (text == null || (text = text.trim()).length() == 0) {
+            throw new IllegalArgumentException("empty lines data");
+        }
+
+        String[] lines = text.split("[\r]?\n");
+        maze = new int[lines.length][lines[0].length()];
+        visited = new boolean[lines.length][lines[0].length()];
+
+        for (int row = 0; row < getHeight(); row++) {
+            if (lines[row].length() != getWidth()) {
+                throw new IllegalArgumentException("line " + (row + 1) + " wrong length (was " + lines[row].length() + " but should be " + getWidth() + ")");
+            }
+
+            for (int col = 0; col < getWidth(); col++) {
+                if (lines[row].charAt(col) == '#')
+                    maze[row][col] = WALL;
+                else if (lines[row].charAt(col) == 'S') {
+                    maze[row][col] = START;
+                    start = new Coordinate(row, col);
+                } else if (lines[row].charAt(col) == 'E') {
+                    maze[row][col] = EXIT;
+                    end = new Coordinate(row, col);
+                } else
+                    maze[row][col] = ROAD;
+            }
+        }
+    }
+
+    public int getHeight() {
+        return maze.length;
+    }
+
+    public int getWidth() {
+        return maze[0].length;
+    }
+
+    public Coordinate getEntry() {
+        return start;
+    }
+
+    public Coordinate getExit() {
+        return end;
+    }
+
+    public boolean isExit(int x, int y) {
+        return x == end.getX() && y == end.getY();
+    }
+
+    public boolean isStart(int x, int y) {
+        return x == start.getX() && y == start.getY();
+    }
+
+    public boolean isExplored(int row, int col) {
+        return visited[row][col];
+    }
+
+    public boolean isWall(int row, int col) {
+        return maze[row][col] == WALL;
+    }
+
+    public void setVisited(int row, int col, boolean value) {
+        visited[row][col] = value;
+    }
+
+    public boolean isValidLocation(int row, int col) {
+        if (row < 0 || row >= getHeight() || col < 0 || col >= getWidth()) {
+            return false;
+        }
+        return true;
+    }
+
+    public void printPath(List<Coordinate> path) {
+        int[][] tempMaze = Arrays.stream(maze)
+            .map(int[]::clone)
+            .toArray(int[][]::new);
+        for (Coordinate coordinate : path) {
+            if (isStart(coordinate.getX(), coordinate.getY()) || isExit(coordinate.getX(), coordinate.getY())) {
+                continue;
+            }
+            tempMaze[coordinate.getX()][coordinate.getY()] = PATH;
+        }
+        System.out.println(toString(tempMaze));
+    }
+
+    public String toString(int[][] maze) {
+        StringBuilder result = new StringBuilder(getWidth() * (getHeight() + 1));
+        for (int row = 0; row < getHeight(); row++) {
+            for (int col = 0; col < getWidth(); col++) {
+                if (maze[row][col] == ROAD) {
+                    result.append(' ');
+                } else if (maze[row][col] == WALL) {
+                    result.append('#');
+                } else if (maze[row][col] == START) {
+                    result.append('S');
+                } else if (maze[row][col] == EXIT) {
+                    result.append('E');
+                } else {
+                    result.append('.');
+                }
+            }
+            result.append('\n');
+        }
+        return result.toString();
+    }
+
+    public void reset() {
+        for (int i = 0; i < visited.length; i++)
+            Arrays.fill(visited[i], false);
+    }
+}
--- a/algorithms/src/main/java/com/baeldung/algorithms/maze/solver/MazeDriver.java
+++ b/algorithms/src/main/java/com/baeldung/algorithms/maze/solver/MazeDriver.java
@ -0,0 +1,34 @@
+package com.baeldung.algorithms.maze.solver;
+
+import java.io.File;
+import java.util.List;
+
+public class MazeDriver {
+    public static void main(String[] args) throws Exception {
+        File maze1 = new File("src/main/resources/maze/maze1.txt");
+        File maze2 = new File("src/main/resources/maze/maze2.txt");
+
+        execute(maze1);
+        execute(maze2);
+    }
+
+    private static void execute(File file) throws Exception {
+        Maze maze = new Maze(file);
+        dfs(maze);
+        bfs(maze);
+    }
+
+    private static void bfs(Maze maze) {
+        BFSMazeSolver bfs = new BFSMazeSolver();
+        List<Coordinate> path = bfs.solve(maze);
+        maze.printPath(path);
+        maze.reset();
+    }
+
+    private static void dfs(Maze maze) {
+        DFSMazeSolver dfs = new DFSMazeSolver();
+        List<Coordinate> path = dfs.solve(maze);
+        maze.printPath(path);
+        maze.reset();
+    }
+}
--- a/algorithms/src/main/java/com/baeldung/algorithms/sudoku/BacktrackingAlgorithm.java
+++ b/algorithms/src/main/java/com/baeldung/algorithms/sudoku/BacktrackingAlgorithm.java
@ -101,4 +101,4 @@ public class BacktrackingAlgorithm {
        }
        return true;
    }
-}
+}
--- a/algorithms/src/main/java/com/baeldung/algorithms/sudoku/DancingLinks.java
+++ b/algorithms/src/main/java/com/baeldung/algorithms/sudoku/DancingLinks.java
@ -120,10 +120,10 @@ public class DancingLinks {
    }

    private static void printSolution(int[][] result) {
-        int N = result.length;
+        int size = result.length;
        for (int[] aResult : result) {
            StringBuilder ret = new StringBuilder();
-            for (int j = 0; j < N; j++) {
+            for (int j = 0; j < size; j++) {
                ret.append(aResult[j]).append(" ");
            }
            System.out.println(ret);
--- a/algorithms/src/main/java/com/baeldung/algorithms/sudoku/DancingLinksAlgorithm.java
+++ b/algorithms/src/main/java/com/baeldung/algorithms/sudoku/DancingLinksAlgorithm.java
@ -39,70 +39,83 @@ public class DancingLinksAlgorithm {
    }

    private boolean[][] createExactCoverBoard() {
-        boolean[][] R = new boolean[BOARD_SIZE * BOARD_SIZE * MAX_VALUE][BOARD_SIZE * BOARD_SIZE * CONSTRAINTS];
+        boolean[][] coverBoard = new boolean[BOARD_SIZE * BOARD_SIZE * MAX_VALUE][BOARD_SIZE * BOARD_SIZE * CONSTRAINTS];

        int hBase = 0;
+        hBase = checkCellConstraint(coverBoard, hBase);
+        hBase = checkRowConstraint(coverBoard, hBase);
+        hBase = checkColumnConstraint(coverBoard, hBase);
+        checkSubsectionConstraint(coverBoard, hBase);
+        
+        return coverBoard;
+    }

-        // Cell constraint.
-        for (int r = COVER_START_INDEX; r <= BOARD_SIZE; r++) {
-            for (int c = COVER_START_INDEX; c <= BOARD_SIZE; c++, hBase++) {
-                for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++) {
-                    int index = getIndex(r, c, n);
-                    R[index][hBase] = true;
-                }
-            }
-        }
-
-        // Row constrain.
-        for (int r = COVER_START_INDEX; r <= BOARD_SIZE; r++) {
-            for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++, hBase++) {
-                for (int c1 = COVER_START_INDEX; c1 <= BOARD_SIZE; c1++) {
-                    int index = getIndex(r, c1, n);
-                    R[index][hBase] = true;
-                }
-            }
-        }
-
-        // Column constraint.
-        for (int c = COVER_START_INDEX; c <= BOARD_SIZE; c++) {
-            for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++, hBase++) {
-                for (int r1 = COVER_START_INDEX; r1 <= BOARD_SIZE; r1++) {
-                    int index = getIndex(r1, c, n);
-                    R[index][hBase] = true;
-                }
-            }
-        }
-
-        // Subsection constraint
+    private int checkSubsectionConstraint(boolean[][] coverBoard, int hBase) {
        for (int br = COVER_START_INDEX; br <= BOARD_SIZE; br += SUBSECTION_SIZE) {
            for (int bc = COVER_START_INDEX; bc <= BOARD_SIZE; bc += SUBSECTION_SIZE) {
                for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++, hBase++) {
                    for (int rDelta = 0; rDelta < SUBSECTION_SIZE; rDelta++) {
                        for (int cDelta = 0; cDelta < SUBSECTION_SIZE; cDelta++) {
                            int index = getIndex(br + rDelta, bc + cDelta, n);
-                            R[index][hBase] = true;
+                            coverBoard[index][hBase] = true;
                        }
                    }
                }
            }
        }
-        return R;
+        return hBase;
+    }
+
+    private int checkColumnConstraint(boolean[][] coverBoard, int hBase) {
+        for (int c = COVER_START_INDEX; c <= BOARD_SIZE; c++) {
+            for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++, hBase++) {
+                for (int r1 = COVER_START_INDEX; r1 <= BOARD_SIZE; r1++) {
+                    int index = getIndex(r1, c, n);
+                    coverBoard[index][hBase] = true;
+                }
+            }
+        }
+        return hBase;
+    }
+
+    private int checkRowConstraint(boolean[][] coverBoard, int hBase) {
+        for (int r = COVER_START_INDEX; r <= BOARD_SIZE; r++) {
+            for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++, hBase++) {
+                for (int c1 = COVER_START_INDEX; c1 <= BOARD_SIZE; c1++) {
+                    int index = getIndex(r, c1, n);
+                    coverBoard[index][hBase] = true;
+                }
+            }
+        }
+        return hBase;
+    }
+
+    private int checkCellConstraint(boolean[][] coverBoard, int hBase) {
+        for (int r = COVER_START_INDEX; r <= BOARD_SIZE; r++) {
+            for (int c = COVER_START_INDEX; c <= BOARD_SIZE; c++, hBase++) {
+                for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++) {
+                    int index = getIndex(r, c, n);
+                    coverBoard[index][hBase] = true;
+                }
+            }
+        }
+        return hBase;
    }

    private boolean[][] initializeExactCoverBoard(int[][] board) {
-        boolean[][] R = createExactCoverBoard();
+        boolean[][] coverBoard = createExactCoverBoard();
        for (int i = COVER_START_INDEX; i <= BOARD_SIZE; i++) {
            for (int j = COVER_START_INDEX; j <= BOARD_SIZE; j++) {
                int n = board[i - 1][j - 1];
                if (n != NO_VALUE) {
                    for (int num = MIN_VALUE; num <= MAX_VALUE; num++) {
                        if (num != n) {
-                            Arrays.fill(R[getIndex(i, j, num)], false);
+                            Arrays.fill(coverBoard[getIndex(i, j, num)], false);
                        }
                    }
                }
            }
        }
-        return R;
+        return coverBoard;
    }
 }
--- a/algorithms/src/main/resources/maze/maze1.txt
+++ b/algorithms/src/main/resources/maze/maze1.txt
@ -0,0 +1,12 @@
+S ########
+#        #
+# ### ## #
+# #    # #
+# #  # # #
+# ## #####
+# #      #
+# # #  # #
+##### ####
+#   #    E
+# #    # #
+##########
--- a/algorithms/src/main/resources/maze/maze2.txt
+++ b/algorithms/src/main/resources/maze/maze2.txt
@ -0,0 +1,22 @@
+S ##########################
+# #      #                 #
+# # ####   ############### #
+# # #    # #               #
+# # #### # # ###############
+# # #    # # #             #
+# # # #### ### ########### #
+# # # #        #           #
+#       ################## #
+#########    # # #       # #
+# #       #### # ####### # #
+# # ### ###  # # #       # #
+#   #       ##   # ##### # #
+##### #######  # #     # # #
+#     #       ## ## #### # #
+# ##### #######     #      #
+#       #       ############
+####### #########        # #
+#       #         ######## #
+# ####### ###### ##   #    E
+#         #         #   ## #
+############################
--- a/core-java-9/src/test/java/com/baeldung/java9/httpclient/HttpClientTest.java
+++ b/core-java-9/src/test/java/com/baeldung/java9/httpclient/HttpClientTest.java
@ -11,6 +11,7 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.stream.Collectors;

@ -116,18 +117,20 @@ public class HttpClientTest {
            .GET()
            .build();

+        ExecutorService executorService = Executors.newFixedThreadPool(2);
+
        CompletableFuture<HttpResponse<String>> response1 = HttpClient.newBuilder()
-            .executor(Executors.newFixedThreadPool(2))
+            .executor(executorService)
            .build()
            .sendAsync(request, HttpResponse.BodyHandler.asString());

        CompletableFuture<HttpResponse<String>> response2 = HttpClient.newBuilder()
-            .executor(Executors.newFixedThreadPool(2))
+            .executor(executorService)
            .build()
            .sendAsync(request, HttpResponse.BodyHandler.asString());

        CompletableFuture<HttpResponse<String>> response3 = HttpClient.newBuilder()
-            .executor(Executors.newFixedThreadPool(2))
+            .executor(executorService)
            .build()
            .sendAsync(request, HttpResponse.BodyHandler.asString());

--- a/core-java-concurrency/src/main/java/com/baeldung/concurrent/prioritytaskexecution/Job.java
+++ b/core-java-concurrency/src/main/java/com/baeldung/concurrent/prioritytaskexecution/Job.java
@ -16,7 +16,8 @@ public class Job implements Runnable {
    @Override
    public void run() {
        try {
-            System.out.println("Job:" + jobName + " Priority:" + jobPriority);
+            System.out.println("Job:" + jobName + 
+              " Priority:" + jobPriority);
            Thread.sleep(1000);
        } catch (InterruptedException ignored) {
        }
--- a/core-java-concurrency/src/main/java/com/baeldung/concurrent/prioritytaskexecution/PriorityJobScheduler.java
+++ b/core-java-concurrency/src/main/java/com/baeldung/concurrent/prioritytaskexecution/PriorityJobScheduler.java
@ -9,21 +9,21 @@ import java.util.concurrent.TimeUnit;
 public class PriorityJobScheduler {

    private ExecutorService priorityJobPoolExecutor;
-    private ExecutorService priorityJobScheduler;
-    private PriorityBlockingQueue<Runnable> priorityQueue;
+    private ExecutorService priorityJobScheduler = 
+      Executors.newSingleThreadExecutor();
+    private PriorityBlockingQueue<Job> priorityQueue;

    public PriorityJobScheduler(Integer poolSize, Integer queueSize) {
        priorityJobPoolExecutor = Executors.newFixedThreadPool(poolSize);
-        Comparator<? super Job> jobComparator = Comparator.comparing(Job::getJobPriority);
-        priorityQueue = new PriorityBlockingQueue<Runnable>(queueSize, 
-          (Comparator<? super Runnable>) jobComparator);
+        priorityQueue = new PriorityBlockingQueue<Job>(queueSize, 
+          Comparator.comparing(Job::getJobPriority));

-        priorityJobScheduler = Executors.newSingleThreadExecutor();
        priorityJobScheduler.execute(()->{
            while (true) {
                try {
                    priorityJobPoolExecutor.execute(priorityQueue.take());
                } catch (InterruptedException e) {
+                    // exception needs special handling
                    break;
                }
            }
--- a/core-java-concurrency/src/test/java/com/baeldung/concurrent/prioritytaskexecution/PriorityJobSchedulerUnitTest.java
+++ b/core-java-concurrency/src/test/java/com/baeldung/concurrent/prioritytaskexecution/PriorityJobSchedulerUnitTest.java
@ -30,7 +30,9 @@ public class PriorityJobSchedulerUnitTest {
        // delay to avoid job sleep (added for demo) being interrupted
        try {
            Thread.sleep(2000);
-        } catch (InterruptedException ignored) {
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            throw new RuntimeException(e);
        }
        
        pjs.closeScheduler();
--- a/core-java/src/main/java/com/baeldung/javac/Data.java
+++ b/core-java/src/main/java/com/baeldung/javac/Data.java
@ -1,28 +1,16 @@
 package com.baeldung.javac;

-import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;

-public class Data implements Serializable {
-    static List<String> textList = new ArrayList();
+public class Data {
+    List<String> textList = new ArrayList();

-    private static void addText() {
-        textList.add("baeldung");
-        textList.add(".");
-        textList.add("com");
+    public void addText(String text) {
+        textList.add(text);
    }

    public List getTextList() {
-        this.addText();
-        List<String> result = new ArrayList<String>();
-        String firstElement = (String) textList.get(0);
-        switch (firstElement) {
-        case "baeldung":
-            result.add("baeldung");
-        case "com":
-            result.add("com");
-        }
-        return result;
+        return this.textList;
    }
-}
+}
--- a/core-java/src/main/java/com/baeldung/string/Palindrome.java
+++ b/core-java/src/main/java/com/baeldung/string/Palindrome.java
@ -0,0 +1,62 @@
+package com.baeldung.string;
+
+import java.util.stream.IntStream;
+
+public class Palindrome {
+
+    public boolean isPalindrome(String text) {
+        text = text.replaceAll("\\s+", "")
+            .toLowerCase();
+        int length = text.length();
+        int forward = 0;
+        int backward = length - 1;
+        boolean palindrome = true;
+        while (backward > forward) {
+            char forwardChar = text.charAt(forward++);
+            char backwardChar = text.charAt(backward--);
+            if (forwardChar != backwardChar)
+                return false;
+        }
+        return palindrome;
+    }
+
+    public boolean isPalindromeReverseTheString(String text) {
+        String reverse = "";
+        text = text.replaceAll("\\s+", "").toLowerCase();
+        char[] plain = text.toCharArray();
+        for (int i = plain.length - 1; i >= 0; i--)
+            reverse += plain[i];
+        return reverse.equals(text);
+    }
+
+    public boolean isPalindromeUsingStringBuilder(String text) {
+        StringBuilder plain = new StringBuilder(text);
+        StringBuilder reverse = plain.reverse();
+        return reverse.equals(plain);
+    }
+
+    public boolean isPalindromeUsingStringBuffer(String text) {
+        StringBuffer plain = new StringBuffer(text);
+        StringBuffer reverse = plain.reverse();
+        return reverse.equals(plain);
+    }
+
+    public boolean isPalindromeRecursive(String text, int forward, int backward) {
+        if (forward == backward)
+            return true;
+        if ((text.charAt(forward)) != (text.charAt(backward)))
+            return false;
+        if (forward < backward + 1) {
+            return isPalindromeRecursive(text, forward + 1, backward - 1);
+        }
+
+        return true;
+    }
+    
+    public boolean isPalindromeUsingIntStream(String text) {
+        String temp  = text.replaceAll("\\s+", "").toLowerCase();
+        return IntStream.range(0, temp.length() / 2)
+            .noneMatch(i -> temp.charAt(i) != temp.charAt(temp.length() - i - 1));
+    }
+    
+}
--- a/core-java/src/test/java/com/baeldung/string/PalindromeTest.java
+++ b/core-java/src/test/java/com/baeldung/string/PalindromeTest.java
@ -0,0 +1,108 @@
+package com.baeldung.string;
+
+import static org.junit.Assert.*;
+import org.junit.Test;
+
+public class PalindromeTest {
+
+    private String[] words = {
+            "Anna",
+            "Civic",
+            "Kayak",
+            "Level",
+            "Madam",
+    };
+
+    private String[] sentences = {
+            "Sore was I ere I saw Eros",
+            "Euston saw I was not Sue",
+            "Too hot to hoot",
+            "No mists or frost Simon",
+            "Stella won no wallets"
+    };
+    
+    private Palindrome palindrome = new Palindrome();
+    
+    @Test
+    public void whenWord_shouldBePalindrome() {
+        for(String word:words)
+            assertTrue(palindrome.isPalindrome(word));
+    }
+
+    @Test
+    public void whenSentence_shouldBePalindrome() {
+        for(String sentence:sentences)
+            assertTrue(palindrome.isPalindrome(sentence));
+    }
+    
+    @Test
+    public void whenReverseWord_shouldBePalindrome() {
+        for(String word:words)
+            assertTrue(palindrome.isPalindromeReverseTheString(word));
+    }
+    
+    @Test
+    public void whenReverseSentence_shouldBePalindrome() {
+        for(String sentence:sentences)
+            assertTrue(palindrome.isPalindromeReverseTheString(sentence));
+    }
+    
+    @Test
+    public void whenStringBuilderWord_shouldBePalindrome() {
+        for(String word:words)
+            assertTrue(palindrome.isPalindromeUsingStringBuilder(word));
+    }
+    
+    @Test
+    public void whenStringBuilderSentence_shouldBePalindrome() {
+        for(String sentence:sentences)
+            assertTrue(palindrome.isPalindromeUsingStringBuilder(sentence));
+    }
+    
+    @Test
+    public void whenStringBufferWord_shouldBePalindrome() {
+        for(String word:words)
+            assertTrue(palindrome.isPalindromeUsingStringBuffer(word));
+    }
+    
+    @Test
+    public void whenStringBufferSentence_shouldBePalindrome() {
+        for(String sentence:sentences)
+            
+            assertTrue(palindrome.isPalindromeUsingStringBuffer(sentence));
+    }
+    
+    @Test
+    public void whenPalindromeRecursive_wordShouldBePalindrome() {
+        for(String word:words) {
+            word = word.replaceAll("\\s+", "").toLowerCase();
+            int backward = word.length()-1;
+            
+            assertTrue(palindrome.isPalindromeRecursive(word,0,backward));
+        }
+    }
+    
+    @Test
+    public void whenPalindromeRecursive_sentenceShouldBePalindrome() {
+        for(String sentence:sentences) {
+            sentence = sentence.replaceAll("\\s+", "").toLowerCase();
+            int backward = sentence.length()-1;
+            
+            assertTrue(palindrome.isPalindromeRecursive(sentence,0,backward));
+        }
+    }
+    
+    @Test
+    public void whenPalindromeStreams_wordShouldBePalindrome() {
+        for(String word:words) {
+            assertTrue(palindrome.isPalindromeUsingIntStream(word));
+        }
+    }
+    
+    @Test
+    public void whenPalindromeStreams_sentenceShouldBePalindrome() {
+        for(String sentence:sentences) {
+            assertTrue(palindrome.isPalindromeUsingIntStream(sentence));
+        }
+    }
+}
--- a/core-kotlin/src/test/kotlin/com/baeldung/kotlin/InfixFunctionsTest.kt
+++ b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/InfixFunctionsTest.kt
@ -0,0 +1,51 @@
+package com.baeldung.kotlin
+
+import org.junit.Assert
+import org.junit.Test
+
+class InfixFunctionsTest {
+    @Test
+    fun testColours() {
+        val color = 0x123456
+        val red = (color and 0xff0000) shr 16
+        val green = (color and 0x00ff00) shr 8
+        val blue = (color and 0x0000ff) shr 0
+
+        Assert.assertEquals(0x12, red)
+        Assert.assertEquals(0x34, green)
+        Assert.assertEquals(0x56, blue)
+    }
+
+    @Test
+    fun testNewAssertions() {
+        class Assertion<T>(private val target: T) {
+            infix fun isEqualTo(other: T) {
+                Assert.assertEquals(other, target)
+            }
+
+            infix fun isDifferentFrom(other: T) {
+                Assert.assertNotEquals(other, target)
+            }
+        }
+
+        val result = Assertion(5)
+
+        result isEqualTo 5
+
+        // The following two lines are expected to fail
+        // result isEqualTo 6
+        // result isDifferentFrom 5
+    }
+
+    @Test
+    fun testNewStringMethod() {
+        infix fun String.substringMatches(r: Regex) : List<String> {
+            return r.findAll(this)
+                    .map { it.value }
+                    .toList()
+        }
+
+        val matches = "a bc def" substringMatches ".*? ".toRegex()
+        Assert.assertEquals(listOf("a ", "bc "), matches)
+    }
+}
--- a/core-kotlin/src/test/kotlin/com/baeldung/kotlin/stdlib/RegexTest.kt
+++ b/core-kotlin/src/test/kotlin/com/baeldung/kotlin/stdlib/RegexTest.kt
@ -0,0 +1,128 @@
+package com.baeldung.kotlin.stdlib
+
+import org.junit.Test
+import java.beans.ExceptionListener
+import java.beans.XMLEncoder
+import java.io.*
+import java.lang.Exception
+import kotlin.test.*
+import kotlin.text.RegexOption.*
+
+class RegexTest {
+
+    @Test
+    fun whenRegexIsInstantiated_thenIsEqualToToRegexMethod() {
+        val pattern = """a([bc]+)d?\\"""
+
+        assertEquals(Regex.fromLiteral(pattern).pattern, pattern)
+        assertEquals(pattern, Regex(pattern).pattern)
+        assertEquals(pattern, pattern.toRegex().pattern)
+    }
+
+    @Test
+    fun whenRegexMatches_thenResultIsTrue() {
+        val regex = """a([bc]+)d?""".toRegex()
+
+        assertTrue(regex.containsMatchIn("xabcdy"))
+        assertTrue(regex.matches("abcd"))
+        assertFalse(regex matches "xabcdy")
+    }
+
+    @Test
+    fun givenCompletelyMatchingRegex_whenMatchResult_thenDestructuring() {
+        val regex = """a([bc]+)d?""".toRegex()
+
+        assertNull(regex.matchEntire("xabcdy"))
+
+        val matchResult = regex.matchEntire("abbccbbd")
+
+        assertNotNull(matchResult)
+        assertEquals(matchResult!!.value, matchResult.groupValues[0])
+        assertEquals(matchResult.destructured.toList(), matchResult.groupValues.drop(1))
+        assertEquals("bbccbb", matchResult.destructured.component1())
+        assertNull(matchResult.next())
+    }
+
+    @Test
+    fun givenPartiallyMatchingRegex_whenMatchResult_thenGroups() {
+        val regex = """a([bc]+)d?""".toRegex()
+        var matchResult = regex.find("abcb abbd")
+
+        assertNotNull(matchResult)
+        assertEquals(matchResult!!.value, matchResult.groupValues[0])
+        assertEquals("abcb", matchResult.value)
+        assertEquals(IntRange(0, 3), matchResult.range)
+        assertEquals(listOf("abcb", "bcb"), matchResult.groupValues)
+        assertEquals(matchResult.destructured.toList(), matchResult.groupValues.drop(1))
+
+        matchResult = matchResult.next()
+
+        assertNotNull(matchResult)
+        assertEquals("abbd", matchResult!!.value)
+        assertEquals("bb", matchResult.groupValues[1])
+
+        matchResult = matchResult.next()
+
+        assertNull(matchResult)
+    }
+
+    @Test
+    fun givenPartiallyMatchingRegex_whenMatchResult_thenDestructuring() {
+        val regex = """([\w\s]+) is (\d+) years old""".toRegex()
+        val matchResult = regex.find("Mickey Mouse is 95 years old")
+        val (name, age) = matchResult!!.destructured
+
+        assertEquals("Mickey Mouse", name)
+        assertEquals("95", age)
+    }
+
+    @Test
+    fun givenNonMatchingRegex_whenFindCalled_thenNull() {
+        val regex = """a([bc]+)d?""".toRegex()
+        val matchResult = regex.find("foo")
+
+        assertNull(matchResult)
+    }
+
+    @Test
+    fun givenNonMatchingRegex_whenFindAllCalled_thenEmptySet() {
+        val regex = """a([bc]+)d?""".toRegex()
+        val matchResults = regex.findAll("foo")
+
+        assertNotNull(matchResults)
+        assertTrue(matchResults.none())
+    }
+
+    @Test
+    fun whenReplace_thenReplacement() {
+        val regex = """(red|green|blue)""".toRegex()
+        val beautiful = "Roses are red, Violets are blue"
+        val grim = regex.replace(beautiful, "dark")
+        val shiny = regex.replaceFirst(beautiful, "rainbow")
+
+        assertEquals("Roses are dark, Violets are dark", grim)
+        assertEquals("Roses are rainbow, Violets are blue", shiny)
+    }
+
+    @Test
+    fun whenComplexReplace_thenReplacement() {
+        val regex = """(red|green|blue)""".toRegex()
+        val beautiful = "Roses are red, Violets are blue"
+        val reallyBeautiful = regex.replace(beautiful) {
+            matchResult ->  matchResult.value.toUpperCase() + "!"
+        }
+
+        assertEquals("Roses are RED!, Violets are BLUE!", reallyBeautiful)
+    }
+
+    @Test
+    fun whenSplit_thenList() {
+        val regex = """\W+""".toRegex()
+        val beautiful = "Roses are red, Violets are blue"
+
+        assertEquals(listOf("Roses", "are", "red", "Violets", "are", "blue"), regex.split(beautiful))
+        assertEquals(listOf("Roses", "are", "red", "Violets are blue"), regex.split(beautiful, 4))
+        assertEquals(regex.toPattern().split(beautiful).asList(), regex.split(beautiful))
+    }
+
+}
--- a/hibernate5/src/main/java/com/baeldung/hibernate/HibernateUtil.java
+++ b/hibernate5/src/main/java/com/baeldung/hibernate/HibernateUtil.java
@ -81,6 +81,7 @@ public class HibernateUtil {
        metadataSources.addAnnotatedClass(Bag.class);
        metadataSources.addAnnotatedClass(PointEntity.class);
        metadataSources.addAnnotatedClass(PolygonEntity.class);
+        metadataSources.addAnnotatedClass(com.baeldung.hibernate.pojo.Person.class);

        Metadata metadata = metadataSources.buildMetadata();
        return metadata.getSessionFactoryBuilder()
--- a/hibernate5/src/main/java/com/baeldung/hibernate/converters/PersonNameConverter.java
+++ b/hibernate5/src/main/java/com/baeldung/hibernate/converters/PersonNameConverter.java
@ -0,0 +1,43 @@
+package com.baeldung.hibernate.converters;
+
+import javax.persistence.AttributeConverter;
+import javax.persistence.Converter;
+
+import com.baeldung.hibernate.pojo.PersonName;
+
+@Converter
+public class PersonNameConverter implements AttributeConverter<PersonName, String> {
+
+    private static final String SEPARATOR = ", ";
+
+    @Override
+    public String convertToDatabaseColumn(PersonName person) {
+        StringBuilder sb = new StringBuilder();
+        if (person.getSurname() != null) {
+            sb.append(person.getSurname());
+            sb.append(SEPARATOR);
+        }
+
+        if (person.getName() != null) {
+            sb.append(person.getName());
+        }
+
+        return sb.toString();
+    }
+
+    @Override
+    public PersonName convertToEntityAttribute(String dbPerson) {
+        String[] pieces = dbPerson.split(SEPARATOR);
+
+        if (pieces == null || pieces.length != 2) {
+            return null;
+        }
+
+        PersonName personName = new PersonName();
+        personName.setSurname(pieces[0]);
+        personName.setName(pieces[1]);
+
+        return personName;
+    }
+
+}
--- a/hibernate5/src/main/java/com/baeldung/hibernate/interceptors/CustomInterceptorImpl.java
+++ b/hibernate5/src/main/java/com/baeldung/hibernate/interceptors/CustomInterceptorImpl.java
@ -9,7 +9,7 @@ import org.hibernate.Interceptor;
 import org.hibernate.Transaction;
 import org.hibernate.type.Type;

-public class CustomInterceptorImpl implements Interceptor {
+public class CustomInterceptorImpl implements Interceptor, Serializable {

    @Override
    public boolean onLoad(Object entity, Serializable id, Object[] state, String[] propertyNames, Type[] types) throws CallbackException {
--- a/hibernate5/src/main/java/com/baeldung/hibernate/pojo/Person.java
+++ b/hibernate5/src/main/java/com/baeldung/hibernate/pojo/Person.java
@ -0,0 +1,32 @@
+package com.baeldung.hibernate.pojo;
+
+import javax.persistence.Convert;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+import com.baeldung.hibernate.converters.PersonNameConverter;
+
+@Entity(name = "PersonTable")
+public class Person {
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    @Convert(converter = PersonNameConverter.class)
+    private PersonName personName;
+
+    public PersonName getPersonName() {
+        return personName;
+    }
+
+    public void setPersonName(PersonName personName) {
+        this.personName = personName;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+}
--- a/hibernate5/src/main/java/com/baeldung/hibernate/pojo/PersonName.java
+++ b/hibernate5/src/main/java/com/baeldung/hibernate/pojo/PersonName.java
@ -0,0 +1,29 @@
+package com.baeldung.hibernate.pojo;
+
+import java.io.Serializable;
+
+public class PersonName implements Serializable {
+
+    private static final long serialVersionUID = 7883094644631050150L;
+
+    private String name;
+
+    private String surname;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getSurname() {
+        return surname;
+    }
+
+    public void setSurname(String surname) {
+        this.surname = surname;
+    }
+
+}
--- a/hibernate5/src/test/java/com/baeldung/hibernate/converter/PersonNameConverterTest.java
+++ b/hibernate5/src/test/java/com/baeldung/hibernate/converter/PersonNameConverterTest.java
@ -0,0 +1,74 @@
+package com.baeldung.hibernate.converter;
+
+import java.io.IOException;
+
+import org.hibernate.Session;
+import org.hibernate.Transaction;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.baeldung.hibernate.HibernateUtil;
+import com.baeldung.hibernate.pojo.Person;
+import com.baeldung.hibernate.pojo.PersonName;
+
+import static org.junit.Assert.assertEquals;
+
+public class PersonNameConverterTest {
+
+    private Session session;
+    private Transaction transaction;
+
+    @Before
+    public void setUp() throws IOException {
+        session = HibernateUtil.getSessionFactory()
+            .openSession();
+        transaction = session.beginTransaction();
+
+        session.createNativeQuery("delete from personTable")
+            .executeUpdate();
+
+        transaction.commit();
+        transaction = session.beginTransaction();
+    }
+
+    @After
+    public void tearDown() {
+        transaction.rollback();
+        session.close();
+    }
+
+    @Test
+    public void givenPersonName_WhenSaving_ThenNameAndSurnameConcat() {
+        final String name = "name";
+        final String surname = "surname";
+
+        PersonName personName = new PersonName();
+        personName.setName(name);
+        personName.setSurname(surname);
+
+        Person person = new Person();
+        person.setPersonName(personName);
+
+        Long id = (Long) session.save(person);
+
+        session.flush();
+        session.clear();
+
+        String dbPersonName = (String) session.createNativeQuery("select p.personName from PersonTable p where p.id = :id")
+            .setParameter("id", id)
+            .getSingleResult();
+
+        assertEquals(surname + ", " + name, dbPersonName);
+
+        Person dbPerson = session.createNativeQuery("select * from PersonTable p where p.id = :id", Person.class)
+            .setParameter("id", id)
+            .getSingleResult();
+
+        assertEquals(dbPerson.getPersonName()
+            .getName(), name);
+        assertEquals(dbPerson.getPersonName()
+            .getSurname(), surname);
+    }
+
+}
--- a/influxdb/README.md
+++ b/influxdb/README.md
@ -2,7 +2,6 @@

 ### Relevant Article:
 - [Introduction to using InfluxDB with Java](http://www.baeldung.com/using-influxdb-with-java/)
- [Using InfluxDB with Java](http://www.baeldung.com/java-influxdb)

 ### Overview
 This Maven project contains the Java code for the article linked above.
--- a/influxdb/src/test/java/com/baeldung/influxdb/InfluxDBConnectionLiveTest.java
+++ b/influxdb/src/test/java/com/baeldung/influxdb/InfluxDBConnectionLiveTest.java
@ -8,7 +8,6 @@ import org.influxdb.dto.*;
 import org.influxdb.impl.InfluxDBResultMapper;
 import org.junit.Test;

-import java.io.IOException;
 import java.util.List;
 import java.util.concurrent.TimeUnit;

@ -103,7 +102,7 @@ public class InfluxDBConnectionLiveTest {
        // another brief pause.
        Thread.sleep(10);

-        List<MemoryPoint> memoryPointList = getPoints(connection, "Select * from memory", "baeldung");
+        List<com.baeldung.influxdb.MemoryPoint> memoryPointList = getPoints(connection, "Select * from memory", "baeldung");

        assertEquals(10, memoryPointList.size());

--- a/jackson/pom.xml
+++ b/jackson/pom.xml
@ -129,7 +129,7 @@

    <properties>
        <!-- marshalling -->
-        <jackson.version>2.9.2</jackson.version>
+        <jackson.version>2.9.4</jackson.version>

        <!-- util -->
        <guava.version>19.0</guava.version>
--- a/javaxval/pom.xml
+++ b/javaxval/pom.xml
@ -6,10 +6,11 @@
    <version>0.1-SNAPSHOT</version>

    <properties>
-        <validation-api.version>2.0.0.Final</validation-api.version>
-        <hibernate-validator.version>6.0.2.Final</hibernate-validator.version>
+        <validation-api.version>2.0.1.Final</validation-api.version>
+        <hibernate-validator.version>6.0.7.Final</hibernate-validator.version>
        <javax.el-api.version>3.0.0</javax.el-api.version>
        <javax.el.version>2.2.6</javax.el.version>
+        <org.springframework.version>5.0.2.RELEASE</org.springframework.version>
    </properties>


@ -21,12 +22,6 @@

    <dependencies>

-        <dependency>
-            <groupId>javax.validation</groupId>
-            <artifactId>validation-api</artifactId>
-            <version>${validation-api.version}</version>
-        </dependency>
-
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-validator</artifactId>
@ -50,6 +45,16 @@
            <artifactId>javax.el</artifactId>
            <version>${javax.el.version}</version>
        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-context</artifactId>
+            <version>${org.springframework.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.springframework</groupId>
+            <artifactId>spring-test</artifactId>
+            <version>${org.springframework.version}</version>
+        </dependency>

    </dependencies>

--- a/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/MethodValidationConfig.java
+++ b/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/MethodValidationConfig.java
@ -0,0 +1,38 @@
+package org.baeldung.javaxval.methodvalidation;
+
+import org.baeldung.javaxval.methodvalidation.model.Customer;
+import org.baeldung.javaxval.methodvalidation.model.Reservation;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Scope;
+import org.springframework.validation.beanvalidation.MethodValidationPostProcessor;
+
+import java.time.LocalDate;
+
+@Configuration
+@ComponentScan({ "org.baeldung.javaxval.methodvalidation.model" })
+public class MethodValidationConfig {
+
+    @Bean
+    public MethodValidationPostProcessor methodValidationPostProcessor() {
+        return new MethodValidationPostProcessor();
+    }
+
+    @Bean("customer")
+    @Scope(BeanDefinition.SCOPE_PROTOTYPE)
+    public Customer customer(String firstName, String lastName) {
+
+        Customer customer = new Customer(firstName, lastName);
+        return customer;
+    }
+
+    @Bean("reservation")
+    @Scope(BeanDefinition.SCOPE_PROTOTYPE)
+    public Reservation reservation(LocalDate begin, LocalDate end, Customer customer, int room) {
+
+        Reservation reservation = new Reservation(begin, end, customer, room);
+        return reservation;
+    }
+}
--- a/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/constraints/ConsistentDateParameterValidator.java
+++ b/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/constraints/ConsistentDateParameterValidator.java
@ -0,0 +1,25 @@
+package org.baeldung.javaxval.methodvalidation.constraints;
+
+import javax.validation.ConstraintValidator;
+import javax.validation.ConstraintValidatorContext;
+import javax.validation.constraintvalidation.SupportedValidationTarget;
+import javax.validation.constraintvalidation.ValidationTarget;
+import java.time.LocalDate;
+
+@SupportedValidationTarget(ValidationTarget.PARAMETERS)
+public class ConsistentDateParameterValidator implements ConstraintValidator<ConsistentDateParameters, Object[]> {
+
+    @Override
+    public boolean isValid(Object[] value, ConstraintValidatorContext context) {
+
+        if (value[0] == null || value[1] == null) {
+            return true;
+        }
+
+        if (!(value[0] instanceof LocalDate) || !(value[1] instanceof LocalDate)) {
+            throw new IllegalArgumentException("Illegal method signature, expected two parameters of type LocalDate.");
+        }
+
+        return ((LocalDate) value[0]).isAfter(LocalDate.now()) && ((LocalDate) value[0]).isBefore((LocalDate) value[1]);
+    }
+}
--- a/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/constraints/ConsistentDateParameters.java
+++ b/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/constraints/ConsistentDateParameters.java
@ -0,0 +1,23 @@
+package org.baeldung.javaxval.methodvalidation.constraints;
+
+import javax.validation.Constraint;
+import javax.validation.Payload;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.*;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+@Constraint(validatedBy = ConsistentDateParameterValidator.class)
+@Target({ METHOD, CONSTRUCTOR })
+@Retention(RUNTIME)
+@Documented
+public @interface ConsistentDateParameters {
+
+    String message() default "End date must be after begin date and both must be in the future";
+
+    Class<?>[] groups() default {};
+
+    Class<? extends Payload>[] payload() default {};
+}
--- a/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/constraints/ValidReservation.java
+++ b/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/constraints/ValidReservation.java
@ -0,0 +1,24 @@
+package org.baeldung.javaxval.methodvalidation.constraints;
+
+import javax.validation.Constraint;
+import javax.validation.Payload;
+import java.lang.annotation.Documented;
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+import static java.lang.annotation.ElementType.CONSTRUCTOR;
+import static java.lang.annotation.ElementType.METHOD;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+@Constraint(validatedBy = ValidReservationValidator.class)
+@Target({ METHOD, CONSTRUCTOR })
+@Retention(RUNTIME)
+@Documented
+public @interface ValidReservation {
+
+    String message() default "End date must be after begin date and both must be in the future, room number must be bigger than 0";
+
+    Class<?>[] groups() default {};
+
+    Class<? extends Payload>[] payload() default {};
+}
--- a/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/constraints/ValidReservationValidator.java
+++ b/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/constraints/ValidReservationValidator.java
@ -0,0 +1,32 @@
+package org.baeldung.javaxval.methodvalidation.constraints;
+
+import org.baeldung.javaxval.methodvalidation.model.Reservation;
+
+import javax.validation.ConstraintValidator;
+import javax.validation.ConstraintValidatorContext;
+import java.time.LocalDate;
+
+public class ValidReservationValidator implements ConstraintValidator<ValidReservation, Reservation> {
+
+    @Override
+    public boolean isValid(Reservation reservation, ConstraintValidatorContext context) {
+
+        if (reservation == null) {
+            return true;
+        }
+
+        if (!(reservation instanceof Reservation)) {
+            throw new IllegalArgumentException("Illegal method signature, expected parameter of type Reservation.");
+        }
+
+        if (reservation.getBegin() == null || reservation.getEnd() == null || reservation.getCustomer() == null) {
+            return false;
+        }
+
+        return (reservation.getBegin()
+            .isAfter(LocalDate.now())
+            && reservation.getBegin()
+                .isBefore(reservation.getEnd())
+            && reservation.getRoom() > 0);
+    }
+}
--- a/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/model/Customer.java
+++ b/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/model/Customer.java
@ -0,0 +1,41 @@
+package org.baeldung.javaxval.methodvalidation.model;
+
+import org.springframework.validation.annotation.Validated;
+
+import javax.validation.constraints.NotNull;
+import javax.validation.constraints.Size;
+
+@Validated
+public class Customer {
+
+    @Size(min = 5, max = 200)
+    private String firstName;
+
+    @Size(min = 5, max = 200)
+    private String lastName;
+
+    public Customer(@Size(min = 5, max = 200) @NotNull String firstName, @Size(min = 5, max = 200) @NotNull String lastName) {
+        this.firstName = firstName;
+        this.lastName = lastName;
+    }
+
+    public Customer() {
+
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+
+    public String getLastName() {
+        return lastName;
+    }
+
+    public void setLastName(String lastName) {
+        this.lastName = lastName;
+    }
+}
--- a/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/model/Reservation.java
+++ b/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/model/Reservation.java
@ -0,0 +1,64 @@
+package org.baeldung.javaxval.methodvalidation.model;
+
+import org.baeldung.javaxval.methodvalidation.constraints.ConsistentDateParameters;
+import org.baeldung.javaxval.methodvalidation.constraints.ValidReservation;
+import org.springframework.validation.annotation.Validated;
+
+import javax.validation.Valid;
+import javax.validation.constraints.Positive;
+import java.time.LocalDate;
+
+@Validated
+public class Reservation {
+
+    private LocalDate begin;
+
+    private LocalDate end;
+
+    @Valid
+    private Customer customer;
+
+    @Positive
+    private int room;
+
+    @ConsistentDateParameters
+    @ValidReservation
+    public Reservation(LocalDate begin, LocalDate end, Customer customer, int room) {
+        this.begin = begin;
+        this.end = end;
+        this.customer = customer;
+        this.room = room;
+    }
+
+    public LocalDate getBegin() {
+        return begin;
+    }
+
+    public void setBegin(LocalDate begin) {
+        this.begin = begin;
+    }
+
+    public LocalDate getEnd() {
+        return end;
+    }
+
+    public void setEnd(LocalDate end) {
+        this.end = end;
+    }
+
+    public Customer getCustomer() {
+        return customer;
+    }
+
+    public void setCustomer(Customer customer) {
+        this.customer = customer;
+    }
+
+    public int getRoom() {
+        return room;
+    }
+
+    public void setRoom(int room) {
+        this.room = room;
+    }
+}
--- a/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/model/ReservationManagement.java
+++ b/javaxval/src/main/java/org/baeldung/javaxval/methodvalidation/model/ReservationManagement.java
@ -0,0 +1,50 @@
+package org.baeldung.javaxval.methodvalidation.model;
+
+import org.baeldung.javaxval.methodvalidation.constraints.ConsistentDateParameters;
+import org.baeldung.javaxval.methodvalidation.constraints.ValidReservation;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.stereotype.Controller;
+import org.springframework.validation.annotation.Validated;
+
+import javax.validation.Valid;
+import javax.validation.constraints.*;
+import java.time.LocalDate;
+import java.util.List;
+
+@Controller
+@Validated
+public class ReservationManagement {
+
+    @Autowired
+    private ApplicationContext applicationContext;
+
+    @ConsistentDateParameters
+    public void createReservation(LocalDate begin, LocalDate end, @NotNull Customer customer) {
+
+        // ...
+    }
+
+    public void createReservation(@NotNull @Future LocalDate begin, @Min(1) int duration, @NotNull Customer customer) {
+
+        // ...
+    }
+
+    public void createReservation(@Valid Reservation reservation) {
+
+        // ...
+    }
+
+    @NotNull
+    @Size(min = 1)
+    public List<@NotNull Customer> getAllCustomers() {
+
+        return null;
+    }
+
+    @Valid
+    public Reservation getReservationById(int id) {
+
+        return null;
+    }
+}
--- a/javaxval/src/test/java/org/baeldung/javaxval/methodvalidation/ContainerValidationIntegrationTest.java
+++ b/javaxval/src/test/java/org/baeldung/javaxval/methodvalidation/ContainerValidationIntegrationTest.java
@ -0,0 +1,97 @@
+package org.baeldung.javaxval.methodvalidation;
+
+import org.baeldung.javaxval.methodvalidation.model.Customer;
+import org.baeldung.javaxval.methodvalidation.model.Reservation;
+import org.baeldung.javaxval.methodvalidation.model.ReservationManagement;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.test.context.support.AnnotationConfigContextLoader;
+
+import javax.validation.ConstraintViolationException;
+import java.time.LocalDate;
+import java.util.List;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = { MethodValidationConfig.class }, loader = AnnotationConfigContextLoader.class)
+public class ContainerValidationIntegrationTest {
+
+    @Autowired
+    ReservationManagement reservationManagement;
+
+    @Rule
+    public final ExpectedException exception = ExpectedException.none();
+
+    @Test
+    public void whenValidationWithInvalidMethodParameters_thenConstraintViolationException() {
+
+        exception.expect(ConstraintViolationException.class);
+        reservationManagement.createReservation(LocalDate.now(), 0, null);
+    }
+
+    @Test
+    public void whenValidationWithValidMethodParameters_thenNoException() {
+
+        reservationManagement.createReservation(LocalDate.now()
+            .plusDays(1), 1, new Customer("William", "Smith"));
+    }
+
+    @Test
+    public void whenCrossParameterValidationWithInvalidParameters_thenConstraintViolationException() {
+
+        exception.expect(ConstraintViolationException.class);
+        reservationManagement.createReservation(LocalDate.now(), LocalDate.now(), null);
+    }
+
+    @Test
+    public void whenCrossParameterValidationWithValidParameters_thenNoException() {
+
+        reservationManagement.createReservation(LocalDate.now()
+            .plusDays(1),
+            LocalDate.now()
+                .plusDays(2),
+            new Customer("William", "Smith"));
+    }
+
+    @Test
+    public void whenValidationWithInvalidReturnValue_thenConstraintViolationException() {
+
+        exception.expect(ConstraintViolationException.class);
+        List<Customer> list = reservationManagement.getAllCustomers();
+    }
+
+    @Test
+    public void whenValidationWithInvalidCascadedValue_thenConstraintViolationException() {
+
+        Customer customer = new Customer();
+        customer.setFirstName("John");
+        customer.setLastName("Doe");
+        Reservation reservation = new Reservation(LocalDate.now()
+            .plusDays(1),
+            LocalDate.now()
+                .plusDays(2),
+            customer, 1);
+
+        exception.expect(ConstraintViolationException.class);
+        reservationManagement.createReservation(reservation);
+    }
+
+    @Test
+    public void whenValidationWithValidCascadedValue_thenCNoException() {
+
+        Customer customer = new Customer();
+        customer.setFirstName("William");
+        customer.setLastName("Smith");
+        Reservation reservation = new Reservation(LocalDate.now()
+            .plusDays(1),
+            LocalDate.now()
+                .plusDays(2),
+            customer, 1);
+
+        reservationManagement.createReservation(reservation);
+    }
+}
--- a/javaxval/src/test/java/org/baeldung/javaxval/methodvalidation/ValidationIntegrationTest.java
+++ b/javaxval/src/test/java/org/baeldung/javaxval/methodvalidation/ValidationIntegrationTest.java
@ -0,0 +1,209 @@
+package org.baeldung.javaxval.methodvalidation;
+
+import org.baeldung.javaxval.methodvalidation.model.Customer;
+import org.baeldung.javaxval.methodvalidation.model.Reservation;
+import org.baeldung.javaxval.methodvalidation.model.ReservationManagement;
+import org.junit.Before;
+import org.junit.Test;
+import static org.junit.Assert.*;
+
+import javax.validation.ConstraintViolation;
+import javax.validation.Validation;
+import javax.validation.ValidatorFactory;
+import javax.validation.executable.ExecutableValidator;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
+import java.time.LocalDate;
+import java.util.Collections;
+import java.util.Set;
+
+public class ValidationIntegrationTest {
+
+    private ExecutableValidator executableValidator;
+
+    @Before
+    public void getExecutableValidator() {
+
+        ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
+        this.executableValidator = factory.getValidator()
+            .forExecutables();
+    }
+
+    @Test
+    public void whenValidationWithInvalidMethodParameters_thenCorrectNumberOfVoilations() throws NoSuchMethodException {
+
+        ReservationManagement object = new ReservationManagement();
+        Method method = ReservationManagement.class.getMethod("createReservation", LocalDate.class, int.class, Customer.class);
+        Object[] parameterValues = { LocalDate.now(), 0, null };
+        Set<ConstraintViolation<ReservationManagement>> violations = executableValidator.validateParameters(object, method, parameterValues);
+
+        assertEquals(3, violations.size());
+    }
+
+    @Test
+    public void whenValidationWithValidMethodParameters_thenZeroVoilations() throws NoSuchMethodException {
+
+        ReservationManagement object = new ReservationManagement();
+        Method method = ReservationManagement.class.getMethod("createReservation", LocalDate.class, int.class, Customer.class);
+        Object[] parameterValues = { LocalDate.now()
+            .plusDays(1), 1, new Customer("John", "Doe") };
+        Set<ConstraintViolation<ReservationManagement>> violations = executableValidator.validateParameters(object, method, parameterValues);
+
+        assertEquals(0, violations.size());
+    }
+
+    @Test
+    public void whenCrossParameterValidationWithInvalidParameters_thenCorrectNumberOfVoilations() throws NoSuchMethodException {
+
+        ReservationManagement object = new ReservationManagement();
+        Method method = ReservationManagement.class.getMethod("createReservation", LocalDate.class, LocalDate.class, Customer.class);
+        Object[] parameterValues = { LocalDate.now(), LocalDate.now(), new Customer("John", "Doe") };
+        Set<ConstraintViolation<ReservationManagement>> violations = executableValidator.validateParameters(object, method, parameterValues);
+
+        assertEquals(1, violations.size());
+    }
+
+    @Test
+    public void whenCrossParameterValidationWithValidParameters_thenZeroVoilations() throws NoSuchMethodException {
+
+        ReservationManagement object = new ReservationManagement();
+        Method method = ReservationManagement.class.getMethod("createReservation", LocalDate.class, LocalDate.class, Customer.class);
+        Object[] parameterValues = { LocalDate.now()
+            .plusDays(1),
+                LocalDate.now()
+                    .plusDays(2),
+                new Customer("John", "Doe") };
+        Set<ConstraintViolation<ReservationManagement>> violations = executableValidator.validateParameters(object, method, parameterValues);
+
+        assertEquals(0, violations.size());
+    }
+
+    @Test
+    public void whenValidationWithInvalidConstructorParameters_thenCorrectNumberOfVoilations() throws NoSuchMethodException {
+
+        Constructor<Customer> constructor = Customer.class.getConstructor(String.class, String.class);
+        Object[] parameterValues = { "John", "Doe" };
+        Set<ConstraintViolation<Customer>> violations = executableValidator.validateConstructorParameters(constructor, parameterValues);
+
+        assertEquals(2, violations.size());
+    }
+
+    @Test
+    public void whenValidationWithValidConstructorParameters_thenZeroVoilations() throws NoSuchMethodException {
+
+        Constructor<Customer> constructor = Customer.class.getConstructor(String.class, String.class);
+        Object[] parameterValues = { "William", "Smith" };
+        Set<ConstraintViolation<Customer>> violations = executableValidator.validateConstructorParameters(constructor, parameterValues);
+
+        assertEquals(0, violations.size());
+    }
+
+    @Test
+    public void whenCrossParameterValidationWithInvalidConstructorParameters_thenCorrectNumberOfVoilations() throws NoSuchMethodException {
+
+        Constructor<Reservation> constructor = Reservation.class.getConstructor(LocalDate.class, LocalDate.class, Customer.class, int.class);
+        Object[] parameterValues = { LocalDate.now(), LocalDate.now(), new Customer("William", "Smith"), 1 };
+        Set<ConstraintViolation<Reservation>> violations = executableValidator.validateConstructorParameters(constructor, parameterValues);
+
+        assertEquals(1, violations.size());
+    }
+
+    @Test
+    public void whenCrossParameterValidationWithValidConstructorParameters_thenZeroVoilations() throws NoSuchMethodException {
+
+        Constructor<Reservation> constructor = Reservation.class.getConstructor(LocalDate.class, LocalDate.class, Customer.class, int.class);
+        Object[] parameterValues = { LocalDate.now()
+            .plusDays(1),
+                LocalDate.now()
+                    .plusDays(2),
+                new Customer("William", "Smith"), 1 };
+        Set<ConstraintViolation<Reservation>> violations = executableValidator.validateConstructorParameters(constructor, parameterValues);
+
+        assertEquals(0, violations.size());
+    }
+
+    @Test
+    public void whenValidationWithInvalidReturnValue_thenCorrectNumberOfVoilations() throws NoSuchMethodException {
+
+        ReservationManagement object = new ReservationManagement();
+        Method method = ReservationManagement.class.getMethod("getAllCustomers");
+        Object returnValue = Collections.<Customer> emptyList();
+        Set<ConstraintViolation<ReservationManagement>> violations = executableValidator.validateReturnValue(object, method, returnValue);
+
+        assertEquals(1, violations.size());
+    }
+
+    @Test
+    public void whenValidationWithValidReturnValue_thenZeroVoilations() throws NoSuchMethodException {
+
+        ReservationManagement object = new ReservationManagement();
+        Method method = ReservationManagement.class.getMethod("getAllCustomers");
+        Object returnValue = Collections.singletonList(new Customer("William", "Smith"));
+        Set<ConstraintViolation<ReservationManagement>> violations = executableValidator.validateReturnValue(object, method, returnValue);
+
+        assertEquals(0, violations.size());
+    }
+
+    @Test
+    public void whenValidationWithInvalidConstructorReturnValue_thenCorrectNumberOfVoilations() throws NoSuchMethodException {
+
+        Constructor<Reservation> constructor = Reservation.class.getConstructor(LocalDate.class, LocalDate.class, Customer.class, int.class);
+        Reservation createdObject = new Reservation(LocalDate.now(), LocalDate.now(), new Customer("William", "Smith"), 0);
+        Set<ConstraintViolation<Reservation>> violations = executableValidator.validateConstructorReturnValue(constructor, createdObject);
+
+        assertEquals(1, violations.size());
+    }
+
+    @Test
+    public void whenValidationWithValidConstructorReturnValue_thenZeroVoilations() throws NoSuchMethodException {
+
+        Constructor<Reservation> constructor = Reservation.class.getConstructor(LocalDate.class, LocalDate.class, Customer.class, int.class);
+        Reservation createdObject = new Reservation(LocalDate.now()
+            .plusDays(1),
+            LocalDate.now()
+                .plusDays(2),
+            new Customer("William", "Smith"), 1);
+        Set<ConstraintViolation<Reservation>> violations = executableValidator.validateConstructorReturnValue(constructor, createdObject);
+
+        assertEquals(0, violations.size());
+    }
+
+    @Test
+    public void whenValidationWithInvalidCascadedValue_thenCorrectNumberOfVoilations() throws NoSuchMethodException {
+
+        ReservationManagement object = new ReservationManagement();
+        Method method = ReservationManagement.class.getMethod("createReservation", Reservation.class);
+        Customer customer = new Customer();
+        customer.setFirstName("John");
+        customer.setLastName("Doe");
+        Reservation reservation = new Reservation(LocalDate.now()
+            .plusDays(1),
+            LocalDate.now()
+                .plusDays(2),
+            customer, 1);
+        Object[] parameterValues = { reservation };
+        Set<ConstraintViolation<ReservationManagement>> violations = executableValidator.validateParameters(object, method, parameterValues);
+
+        assertEquals(2, violations.size());
+    }
+
+    @Test
+    public void whenValidationWithValidCascadedValue_thenCorrectNumberOfVoilations() throws NoSuchMethodException {
+
+        ReservationManagement object = new ReservationManagement();
+        Method method = ReservationManagement.class.getMethod("createReservation", Reservation.class);
+        Customer customer = new Customer();
+        customer.setFirstName("William");
+        customer.setLastName("Smith");
+        Reservation reservation = new Reservation(LocalDate.now()
+            .plusDays(1),
+            LocalDate.now()
+                .plusDays(2),
+            customer, 1);
+        Object[] parameterValues = { reservation };
+        Set<ConstraintViolation<ReservationManagement>> violations = executableValidator.validateParameters(object, method, parameterValues);
+
+        assertEquals(0, violations.size());
+    }
+
+}
--- a/jgroups/README.md
+++ b/jgroups/README.md
@ -0,0 +1,15 @@
+## Reliable Messaging with JGroups Tutorial Project
+
+### Relevant Article:
+- [Reliable Messaging with JGroups](http://www.baeldung.com/reliable-messaging-with-jgroups/)
+
+### Overview
+This Maven project contains the Java code for the article linked above.
+
+### Package Organization
+Java classes for the intro tutorial are in the org.baeldung.jgroups package.
+
+
+### Running the tests
+
+```
--- a/jgroups/pom.xml
+++ b/jgroups/pom.xml
@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>jgroups</artifactId>
+    <version>0.1-SNAPSHOT</version>
+    <packaging>jar</packaging>
+    <name>jgroups</name>
+    <description>Reliable Messaging with JGroups Tutorial</description>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+    </parent>
+
+    <dependencies>
+        <dependency>
+            <groupId>org.jgroups</groupId>
+            <artifactId>jgroups</artifactId>
+            <version>4.0.10.Final</version>
+        </dependency>
+
+        <dependency>
+            <groupId>commons-cli</groupId>
+            <artifactId>commons-cli</artifactId>
+            <version>1.4</version>
+        </dependency>
+    </dependencies>
+
+    <properties>
+        <java.version>1.8</java.version>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+</project>
--- a/jgroups/src/main/java/com/baeldung/jgroups/JGroupsMessenger.java
+++ b/jgroups/src/main/java/com/baeldung/jgroups/JGroupsMessenger.java
@ -0,0 +1,212 @@
+package com.baeldung.jgroups;
+
+import org.apache.commons.cli.*;
+import org.jgroups.*;
+import org.jgroups.util.Util;
+
+import java.io.*;
+import java.util.List;
+import java.util.Optional;
+
+public class JGroupsMessenger extends ReceiverAdapter {
+
+    private JChannel channel;
+    private String userName;
+    private String clusterName;
+    private View lastView;
+    private boolean running = true;
+
+    // Our shared state
+    private Integer messageCount = 0;
+
+    /**
+     * Connect to a JGroups cluster using command line options
+     * @param args command line arguments
+     * @throws Exception
+     */
+    private void start(String[] args) throws Exception {
+        processCommandline(args);
+
+        // Create the channel
+        // This file could be moved, or made a command line option.
+        channel = new JChannel("src/main/resources/udp.xml");
+
+        // Set a name
+        channel.name(userName);
+
+        // Register for callbacks
+        channel.setReceiver(this);
+
+        // Ignore our messages
+        channel.setDiscardOwnMessages(true);
+
+        // Connect
+        channel.connect(clusterName);
+
+        // Start state transfer
+        channel.getState(null, 0);
+
+        // Do the things
+        processInput();
+
+        // Clean up
+        channel.close();
+
+    }
+
+    /**
+     * Quick and dirty implementaton of commons cli for command line args
+     * @param args the command line args
+     * @throws ParseException
+     */
+    private void processCommandline(String[] args) throws ParseException {
+
+        // Options, parser, friendly help
+        Options options = new Options();
+        CommandLineParser parser = new DefaultParser();
+        HelpFormatter formatter = new HelpFormatter();
+
+        options.addOption("u", "user", true, "User name")
+            .addOption("c", "cluster", true, "Cluster name");
+
+        CommandLine line = parser.parse(options, args);
+
+        if (line.hasOption("user")) {
+            userName = line.getOptionValue("user");
+        } else {
+            formatter.printHelp("JGroupsMessenger: need a user name.\n", options);
+            System.exit(-1);
+        }
+
+        if (line.hasOption("cluster")) {
+            clusterName = line.getOptionValue("cluster");
+        } else {
+            formatter.printHelp("JGroupsMessenger: need a cluster name.\n", options);
+            System.exit(-1);
+        }
+    }
+
+    // Start it up
+    public static void main(String[] args) throws Exception {
+        new JGroupsMessenger().start(args);
+    }
+
+
+    @Override
+    public void viewAccepted(View newView) {
+
+        // Save view if this is the first
+        if (lastView == null) {
+            System.out.println("Received initial view:");
+            newView.forEach(System.out::println);
+        } else {
+            // Compare to last view
+            System.out.println("Received new view.");
+
+            List<Address> newMembers = View.newMembers(lastView, newView);
+            System.out.println("New members: ");
+            newMembers.forEach(System.out::println);
+
+            List<Address> exMembers = View.leftMembers(lastView, newView);
+            System.out.println("Exited members:");
+            exMembers.forEach(System.out::println);
+        }
+        lastView = newView;
+    }
+
+    /**
+     * Loop on console input until we see 'x' to exit
+     */
+    private void processInput() throws Exception {
+
+        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
+        while (running) {
+            try {
+
+                // Get a destination, <enter> means broadcast
+                Address destination = null;
+                System.out.print("Enter a destination: ");
+                System.out.flush();
+                String destinationName = in.readLine().toLowerCase();
+
+                if (destinationName.equals("x")) {
+                    running = false;
+                    continue;
+                } else if (!destinationName.isEmpty()) {
+                    destination = getAddress(destinationName)
+                      . orElseThrow(() -> new Exception("Destination not found"));
+                }
+
+                // Accept a string to send
+                System.out.print("Enter a message: ");
+                System.out.flush();
+                String line = in.readLine().toLowerCase();
+                sendMessage(destination, line);
+            } catch (IOException ioe) {
+                running = false;
+            }
+        }
+        System.out.println("Exiting.");
+    }
+
+    /**
+     * Send message from here
+     * @param destination the destination
+     * @param messageString the message
+     */
+    private void sendMessage(Address destination, String messageString) {
+        try {
+            System.out.println("Sending " + messageString + " to " + destination);
+            Message message = new Message(destination, messageString);
+            channel.send(message);
+        } catch (Exception exception) {
+            System.err.println("Exception sending message: " + exception.getMessage());
+            running = false;
+        }
+    }
+
+    @Override
+    public void receive(Message message) {
+        // Print source and dest with message
+        String line = "Message received from: " + message.getSrc() + " to: " + message.getDest() + " -> " + message.getObject();
+
+        // Only track the count of broadcast messages
+        // Tracking direct message would make for a pointless state
+        if (message.getDest() == null) {
+            messageCount++;
+            System.out.println("Message count: " + messageCount);
+        }
+
+        System.out.println(line);
+    }
+
+    @Override
+    public void getState(OutputStream output) throws Exception {
+        // Serialize into the stream
+        Util.objectToStream(messageCount, new DataOutputStream(output));
+    }
+
+    @Override
+    public void setState(InputStream input) {
+
+        // NOTE: since we know that incrementing the count and transferring the state
+        // is done inside the JChannel's thread, we don't have to worry about synchronizing
+        // messageCount. For production code it should be synchronized!
+        try {
+            // Deserialize
+            messageCount = Util.objectFromStream(new DataInputStream(input));
+        } catch (Exception e) {
+            System.out.println("Error deserialing state!");
+        }
+        System.out.println(messageCount + " is the current messagecount.");
+    }
+
+
+    private Optional<Address> getAddress(String name) {
+        View view = channel.view();
+        return view.getMembers().stream().filter(address -> name.equals(address.toString())).findFirst();
+    }
+
+}
+
+
--- a/jgroups/src/main/resources/udp.xml
+++ b/jgroups/src/main/resources/udp.xml
@ -0,0 +1,48 @@
+<config xmlns="urn:org:jgroups"
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:schemaLocation="urn:org:jgroups http://www.jgroups.org/schema/jgroups.xsd">
+    <UDP
+         mcast_port="${jgroups.udp.mcast_port:45588}"
+         ip_ttl="4"
+         tos="8"
+         ucast_recv_buf_size="5M"
+         ucast_send_buf_size="5M"
+         mcast_recv_buf_size="5M"
+         mcast_send_buf_size="5M"
+         max_bundle_size="64K"
+         enable_diagnostics="true"
+         thread_naming_pattern="cl"
+
+         thread_pool.min_threads="0"
+         thread_pool.max_threads="20"
+         thread_pool.keep_alive_time="30000"/>
+
+    <PING />
+    <MERGE3 max_interval="30000"
+            min_interval="10000"/>
+    <FD_SOCK/>
+    <FD_ALL/>
+    <VERIFY_SUSPECT timeout="1500"  />
+    <BARRIER />
+    <pbcast.NAKACK2 xmit_interval="500"
+                    xmit_table_num_rows="100"
+                    xmit_table_msgs_per_row="2000"
+                    xmit_table_max_compaction_time="30000"
+                    use_mcast_xmit="false"
+                    discard_delivered_msgs="true"/>
+    <UNICAST3 xmit_interval="500"
+              xmit_table_num_rows="100"
+              xmit_table_msgs_per_row="2000"
+              xmit_table_max_compaction_time="60000"
+              conn_expiry_timeout="0"/>
+    <pbcast.STABLE desired_avg_gossip="50000"
+                   max_bytes="4M"/>
+    <pbcast.GMS print_local_addr="true" join_timeout="2000"/>
+    <UFC max_credits="2M"
+         min_threshold="0.4"/>
+    <MFC max_credits="2M"
+         min_threshold="0.4"/>
+    <FRAG2 frag_size="60K"  />
+    <RSVP resend_interval="2000" timeout="10000"/>
+    <pbcast.STATE_TRANSFER />
+</config>
--- a/libraries/README.md
+++ b/libraries/README.md
@ -59,6 +59,7 @@
 - [Intro to JDO Queries 2/2](http://www.baeldung.com/jdo-queries)
 - [Guide to google-http-client](http://www.baeldung.com/google-http-client)
 - [Interact with Google Sheets from Java](http://www.baeldung.com/google-sheets-java-client)
+- [Programatically Create, Configure, and Run a Tomcat Server] (http://www.baeldung.com/tomcat-programmatic-setup)



--- a/libraries/pom.xml
+++ b/libraries/pom.xml
@ -716,6 +716,13 @@
            <classifier>test</classifier>
            <scope>test</scope>
        </dependency>
+
+        <!-- tomcat -->
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-catalina</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
        <dependency>
            <groupId>org.milyn</groupId>
            <artifactId>milyn-smooks-all</artifactId>
@ -802,6 +809,7 @@
        <kafka.version>1.0.0</kafka.version>
        <smooks.version>1.7.0</smooks.version>
        <docker.version>3.0.14</docker.version>
+        <tomcat.version>8.5.24</tomcat.version>
        <async.http.client.version>2.2.0</async.http.client.version>
    </properties>
 </project>
--- a/libraries/src/main/java/com/baeldung/tomcat/MyFilter.java
+++ b/libraries/src/main/java/com/baeldung/tomcat/MyFilter.java
@ -0,0 +1,31 @@
+package com.baeldung.tomcat;
+
+import javax.servlet.*;
+import javax.servlet.annotation.WebFilter;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * Created by adi on 1/14/18.
+ */
+@WebFilter(urlPatterns = "/my-servlet/*")
+public class MyFilter implements Filter {
+
+    @Override
+    public void init(FilterConfig filterConfig) {
+
+    }
+
+    @Override
+    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
+        System.out.println("Filtering stuff...");
+        HttpServletResponse httpResponse = (HttpServletResponse) response;
+        httpResponse.addHeader("myHeader", "myHeaderValue");
+        chain.doFilter(request, httpResponse);
+    }
+
+    @Override
+    public void destroy() {
+
+    }
+}
--- a/libraries/src/main/java/com/baeldung/tomcat/MyServlet.java
+++ b/libraries/src/main/java/com/baeldung/tomcat/MyServlet.java
@ -0,0 +1,25 @@
+package com.baeldung.tomcat;
+
+import javax.servlet.annotation.WebServlet;
+import javax.servlet.http.HttpServlet;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * Created by adi on 1/10/18.
+ */
+@WebServlet(
+  name = "com.baeldung.tomcat.programmatic.MyServlet",
+  urlPatterns = {"/my-servlet"}
+)
+public class MyServlet extends HttpServlet {
+
+    @Override
+    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {
+        resp.setStatus(HttpServletResponse.SC_OK);
+        resp.getWriter().write("test");
+        resp.getWriter().flush();
+        resp.getWriter().close();
+    }
+}
--- a/libraries/src/main/java/com/baeldung/tomcat/ProgrammaticTomcat.java
+++ b/libraries/src/main/java/com/baeldung/tomcat/ProgrammaticTomcat.java
@ -0,0 +1,63 @@
+package com.baeldung.tomcat;
+
+import org.apache.catalina.Context;
+import org.apache.catalina.LifecycleException;
+import org.apache.catalina.startup.Tomcat;
+import org.apache.tomcat.util.descriptor.web.FilterDef;
+import org.apache.tomcat.util.descriptor.web.FilterMap;
+
+import java.io.File;
+
+/**
+ * Created by adi on 1/10/18.
+ */
+public class ProgrammaticTomcat {
+
+    private Tomcat tomcat = null;
+
+    //uncomment for live test
+    //    public static void main(String[] args) throws LifecycleException, ServletException, URISyntaxException, IOException {
+    //        startTomcat();
+    //    }
+
+    public void startTomcat() throws LifecycleException {
+        tomcat = new Tomcat();
+        tomcat.setPort(8080);
+        tomcat.setHostname("localhost");
+        String appBase = ".";
+        tomcat
+          .getHost()
+          .setAppBase(appBase);
+
+        File docBase = new File(System.getProperty("java.io.tmpdir"));
+        Context context = tomcat.addContext("", docBase.getAbsolutePath());
+
+        //add a servlet
+        Class servletClass = MyServlet.class;
+        Tomcat.addServlet(context, servletClass.getSimpleName(), servletClass.getName());
+        context.addServletMappingDecoded("/my-servlet/*", servletClass.getSimpleName());
+
+        //add a filter and filterMapping
+        Class filterClass = MyFilter.class;
+        FilterDef myFilterDef = new FilterDef();
+        myFilterDef.setFilterClass(filterClass.getName());
+        myFilterDef.setFilterName(filterClass.getSimpleName());
+        context.addFilterDef(myFilterDef);
+
+        FilterMap myFilterMap = new FilterMap();
+        myFilterMap.setFilterName(filterClass.getSimpleName());
+        myFilterMap.addURLPattern("/my-servlet/*");
+        context.addFilterMap(myFilterMap);
+
+        tomcat.start();
+        //uncomment for live test
+        //        tomcat
+        //          .getServer()
+        //          .await();
+    }
+
+    public void stopTomcat() throws LifecycleException {
+        tomcat.stop();
+        tomcat.destroy();
+    }
+}
--- a/libraries/src/test/java/com/baeldung/tomcat/ProgrammaticTomcatTest.java
+++ b/libraries/src/test/java/com/baeldung/tomcat/ProgrammaticTomcatTest.java
@ -0,0 +1,62 @@
+package com.baeldung.tomcat;
+
+import org.apache.http.HttpEntity;
+import org.apache.http.HttpResponse;
+import org.apache.http.HttpStatus;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClientBuilder;
+import org.apache.http.util.EntityUtils;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.BlockJUnit4ClassRunner;
+
+
+import static junit.framework.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * Created by adi on 1/14/18.
+ */
+@RunWith(BlockJUnit4ClassRunner.class)
+public class ProgrammaticTomcatTest {
+
+    private ProgrammaticTomcat tomcat = new ProgrammaticTomcat();
+
+    @Before
+    public void setUp() throws Exception {
+        tomcat.startTomcat();
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        tomcat.stopTomcat();
+    }
+
+    @Test
+    public void givenTomcatStarted_whenAccessServlet_responseIsTestAndResponseHeaderIsSet() throws Exception {
+        CloseableHttpClient httpClient = HttpClientBuilder
+          .create()
+          .build();
+        HttpGet getServlet = new HttpGet("http://localhost:8080/my-servlet");
+
+        HttpResponse response = httpClient.execute(getServlet);
+        assertEquals(HttpStatus.SC_OK, response
+          .getStatusLine()
+          .getStatusCode());
+
+        String myHeaderValue = response
+          .getFirstHeader("myHeader")
+          .getValue();
+        assertEquals("myHeaderValue", myHeaderValue);
+
+        HttpEntity responseEntity = response.getEntity();
+        assertNotNull(responseEntity);
+
+        String responseString = EntityUtils.toString(responseEntity, "UTF-8");
+        assertEquals("test", responseString);
+    }
+
+}
--- a/logging-modules/README.md
+++ b/logging-modules/README.md
@ -4,3 +4,4 @@
 ### Relevant Articles:

 - [Creating a Custom Logback Appender](http://www.baeldung.com/custom-logback-appender)
+- [Get Log Output in JSON Format](http://www.baeldung.com/java-log-json-output)
--- a/mesos-marathon/README.md
+++ b/mesos-marathon/README.md
@ -1,3 +1,5 @@
 ### Relevant articles

 - [Simple Jenkins Pipeline with Marathon and Mesos](http://www.baeldung.com/jenkins-pipeline-with-marathon-mesos)
+
+    To run the pipeline, please modify the dockerise.sh file with your own useranema and password for docker login.
--- a/persistence-modules/spring-data-redis/pom.xml
+++ b/persistence-modules/spring-data-redis/pom.xml
@ -16,11 +16,13 @@

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <spring.version>4.3.7.RELEASE</spring.version>
-        <spring-data-redis>1.8.1.RELEASE</spring-data-redis>
+        <spring.version>5.0.3.RELEASE</spring.version>
+        <spring-data-redis>2.0.3.RELEASE</spring-data-redis>
        <cglib.version>3.2.4</cglib.version>
        <jedis.version>2.9.0</jedis.version>
        <nosqlunit.version>0.10.0</nosqlunit.version>
+        <spring-data-commons.version>2.0.3.RELEASE</spring-data-commons.version>
+        
    </properties>

    <dependencies>
@ -73,6 +75,12 @@
            <artifactId>nosqlunit-redis</artifactId>
            <version>${nosqlunit.version}</version>
        </dependency>
+        
+        <dependency>
+    		<groupId>org.springframework.data</groupId>
+    		<artifactId>spring-data-commons</artifactId>
+    		<version>${spring-data-commons.version}</version>
+		</dependency>
    </dependencies>

 </project>
--- a/persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/config/RedisConfig.java
+++ b/persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/config/RedisConfig.java
@ -1,8 +1,5 @@
 package com.baeldung.spring.data.redis.config;

-import com.baeldung.spring.data.redis.queue.MessagePublisher;
-import com.baeldung.spring.data.redis.queue.RedisMessagePublisher;
-import com.baeldung.spring.data.redis.queue.RedisMessageSubscriber;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.ComponentScan;
 import org.springframework.context.annotation.Configuration;
@ -11,10 +8,16 @@ import org.springframework.data.redis.core.RedisTemplate;
 import org.springframework.data.redis.listener.ChannelTopic;
 import org.springframework.data.redis.listener.RedisMessageListenerContainer;
 import org.springframework.data.redis.listener.adapter.MessageListenerAdapter;
+import org.springframework.data.redis.repository.configuration.EnableRedisRepositories;
 import org.springframework.data.redis.serializer.GenericToStringSerializer;

+import com.baeldung.spring.data.redis.queue.MessagePublisher;
+import com.baeldung.spring.data.redis.queue.RedisMessagePublisher;
+import com.baeldung.spring.data.redis.queue.RedisMessageSubscriber;
+
@Configuration
@ComponentScan("com.baeldung.spring.data.redis")
+@EnableRedisRepositories(basePackages = "com.baeldung.spring.data.redis.repo")
 public class RedisConfig {

    @Bean
--- a/persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/model/Student.java
+++ b/persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/model/Student.java
@ -2,6 +2,9 @@ package com.baeldung.spring.data.redis.model;

 import java.io.Serializable;

+import org.springframework.data.redis.core.RedisHash;
+
+@RedisHash("Student")
 public class Student implements Serializable {

    public enum Gender {
--- a/persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/repo/StudentRepository.java
+++ b/persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/repo/StudentRepository.java
@ -1,18 +1,9 @@
 package com.baeldung.spring.data.redis.repo;

+import org.springframework.data.repository.CrudRepository;
+import org.springframework.stereotype.Repository;
+
 import com.baeldung.spring.data.redis.model.Student;

-import java.util.Map;
-
-public interface StudentRepository {
-
-    void saveStudent(Student person);
-
-    void updateStudent(Student student);
-
-    Student findStudent(String id);
-
-    Map<Object, Object> findAllStudents();
-
-    void deleteStudent(String id);
-}
+@Repository
+public interface StudentRepository extends CrudRepository<Student, String> {}
--- a/persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/repo/StudentRepositoryImpl.java
+++ b/persistence-modules/spring-data-redis/src/main/java/com/baeldung/spring/data/redis/repo/StudentRepositoryImpl.java
@ -1,49 +0,0 @@
-package com.baeldung.spring.data.redis.repo;
-
-import com.baeldung.spring.data.redis.model.Student;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.data.redis.core.HashOperations;
-import org.springframework.data.redis.core.RedisTemplate;
-import org.springframework.stereotype.Repository;
-
-import javax.annotation.PostConstruct;
-import java.util.Map;
-
-@Repository
-public class StudentRepositoryImpl implements StudentRepository {
-
-    private static final String KEY = "Student";
-
-    private RedisTemplate<String, Object> redisTemplate;
-    private HashOperations hashOperations;
-
-    @Autowired
-    public StudentRepositoryImpl(RedisTemplate<String, Object> redisTemplate) {
-        this.redisTemplate = redisTemplate;
-    }
-
-    @PostConstruct
-    private void init() {
-        hashOperations = redisTemplate.opsForHash();
-    }
-
-    public void saveStudent(final Student student) {
-        hashOperations.put(KEY, student.getId(), student);
-    }
-
-    public void updateStudent(final Student student) {
-        hashOperations.put(KEY, student.getId(), student);
-    }
-
-    public Student findStudent(final String id) {
-        return (Student) hashOperations.get(KEY, id);
-    }
-
-    public Map<Object, Object> findAllStudents() {
-        return hashOperations.entries(KEY);
-    }
-
-    public void deleteStudent(final String id) {
-        hashOperations.delete(KEY, id);
-    }
-}
--- a/persistence-modules/spring-data-redis/src/test/java/com/baeldung/spring/data/redis/repo/StudentRepositoryIntegrationTest.java
+++ b/persistence-modules/spring-data-redis/src/test/java/com/baeldung/spring/data/redis/repo/StudentRepositoryIntegrationTest.java
@ -1,17 +1,20 @@
 package com.baeldung.spring.data.redis.repo;

-import com.baeldung.spring.data.redis.config.RedisConfig;
-import com.baeldung.spring.data.redis.model.Student;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

-import java.util.Map;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNull;
+import com.baeldung.spring.data.redis.config.RedisConfig;
+import com.baeldung.spring.data.redis.model.Student;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = RedisConfig.class)
@ -23,18 +26,18 @@ public class StudentRepositoryIntegrationTest {
    @Test
    public void whenSavingStudent_thenAvailableOnRetrieval() throws Exception {
        final Student student = new Student("Eng2015001", "John Doe", Student.Gender.MALE, 1);
-        studentRepository.saveStudent(student);
-        final Student retrievedStudent = studentRepository.findStudent(student.getId());
+        studentRepository.save(student);
+        final Student retrievedStudent = studentRepository.findById(student.getId()).get();
        assertEquals(student.getId(), retrievedStudent.getId());
    }

    @Test
    public void whenUpdatingStudent_thenAvailableOnRetrieval() throws Exception {
        final Student student = new Student("Eng2015001", "John Doe", Student.Gender.MALE, 1);
-        studentRepository.saveStudent(student);
+        studentRepository.save(student);
        student.setName("Richard Watson");
-        studentRepository.saveStudent(student);
-        final Student retrievedStudent = studentRepository.findStudent(student.getId());
+        studentRepository.save(student);
+        final Student retrievedStudent = studentRepository.findById(student.getId()).get();
        assertEquals(student.getName(), retrievedStudent.getName());
    }

@ -42,18 +45,19 @@ public class StudentRepositoryIntegrationTest {
    public void whenSavingStudents_thenAllShouldAvailableOnRetrieval() throws Exception {
        final Student engStudent = new Student("Eng2015001", "John Doe", Student.Gender.MALE, 1);
        final Student medStudent = new Student("Med2015001", "Gareth Houston", Student.Gender.MALE, 2);
-        studentRepository.saveStudent(engStudent);
-        studentRepository.saveStudent(medStudent);
-        final Map<Object, Object> retrievedStudent = studentRepository.findAllStudents();
-        assertEquals(retrievedStudent.size(), 2);
+        studentRepository.save(engStudent);
+        studentRepository.save(medStudent);
+        List<Student> students = new ArrayList<>();
+        studentRepository.findAll().forEach(students::add);
+        assertEquals(students.size(), 2);
    }

    @Test
    public void whenDeletingStudent_thenNotAvailableOnRetrieval() throws Exception {
        final Student student = new Student("Eng2015001", "John Doe", Student.Gender.MALE, 1);
-        studentRepository.saveStudent(student);
-        studentRepository.deleteStudent(student.getId());
-        final Student retrievedStudent = studentRepository.findStudent(student.getId());
+        studentRepository.save(student);
+        studentRepository.deleteById(student.getId());
+        final Student retrievedStudent = studentRepository.findById(student.getId()).orElse(null);
        assertNull(retrievedStudent);
    }
 }
--- a/pom.xml
+++ b/pom.xml
@ -49,7 +49,9 @@
        <module>core-java</module>
        <module>core-java-io</module>
        <module>core-java-8</module>
+		<!--
        <module>core-java-concurrency</module>
+		-->
        <module>couchbase</module>

        <module>deltaspike</module>
@ -93,6 +95,7 @@
        <module>javax-servlets</module>
        <module>javaxval</module>
        <module>jaxb</module>
+        <module>jgroups</module>
        <module>jee-7</module>
        <!-- <module>jhipster/jhipster-monolithic</module> -->
        <module>jjwt</module>
--- a/reactor-core/pom.xml
+++ b/reactor-core/pom.xml
@ -26,11 +26,17 @@
            <version>${assertj.version}</version>
            <scope>test</scope>
        </dependency>
-
+	
+	<dependency>
+            <groupId>io.projectreactor</groupId>
+	    <artifactId>reactor-test</artifactId>
+            <version>${reactor-core.version}</version>
+	    <scope>test</scope>
+	</dependency>
    </dependencies>

    <properties>
-        <reactor-core.version>3.0.5.RELEASE</reactor-core.version>
+        <reactor-core.version>3.1.3.RELEASE</reactor-core.version>
        <assertj.version>3.6.1</assertj.version>
    </properties>

--- a/reactor-core/src/test/java/com/baeldung/reactor/core/CombiningPublishersTest.java
+++ b/reactor-core/src/test/java/com/baeldung/reactor/core/CombiningPublishersTest.java
@ -0,0 +1,182 @@
+package com.baeldung.reactor.core;
+
+import java.time.Duration;
+
+import org.junit.Test;
+
+import reactor.core.publisher.Flux;
+import reactor.test.StepVerifier;
+
+public class CombiningPublishersTest {
+    
+    private static Integer min = 1;
+    private static Integer max = 5;
+
+    private static Flux<Integer> evenNumbers = Flux.range(min, max).filter(x -> x % 2 == 0);
+    private static Flux<Integer> oddNumbers = Flux.range(min, max).filter(x -> x % 2 > 0);
+    
+    
+    @Test
+    public void testMerge() {
+        Flux<Integer> fluxOfIntegers = Flux.merge(
+                evenNumbers, 
+                oddNumbers);
+        
+        StepVerifier.create(fluxOfIntegers)
+        .expectNext(2)
+        .expectNext(4)
+        .expectNext(1)
+        .expectNext(3)
+        .expectNext(5)
+        .expectComplete()
+        .verify();
+    }
+    
+    @Test
+    public void testMergeWithDelayedElements() {
+        Flux<Integer> fluxOfIntegers = Flux.merge(
+                evenNumbers.delayElements(Duration.ofMillis(500L)), 
+                oddNumbers.delayElements(Duration.ofMillis(300L)));
+        
+        StepVerifier.create(fluxOfIntegers)
+        .expectNext(1)
+        .expectNext(2)
+        .expectNext(3)
+        .expectNext(5)
+        .expectNext(4)
+        .expectComplete()
+        .verify();
+    }
+    
+    @Test
+    public void testConcat() {
+        Flux<Integer> fluxOfIntegers = Flux.concat(
+                evenNumbers.delayElements(Duration.ofMillis(500L)), 
+                oddNumbers.delayElements(Duration.ofMillis(300L)));
+        
+        StepVerifier.create(fluxOfIntegers)
+        .expectNext(2)
+        .expectNext(4)
+        .expectNext(1)
+        .expectNext(3)
+        .expectNext(5)
+        .expectComplete()
+        .verify();
+    }
+    
+    @Test
+    public void testConcatWith() {
+        Flux<Integer> fluxOfIntegers = evenNumbers
+                .concatWith(oddNumbers);
+        
+        StepVerifier.create(fluxOfIntegers)
+        .expectNext(2)
+        .expectNext(4)
+        .expectNext(1)
+        .expectNext(3)
+        .expectNext(5)
+        .expectComplete()
+        .verify();
+    }
+    
+    @Test
+    public void testCombineLatest() {
+        Flux<Integer> fluxOfIntegers = Flux.combineLatest(
+                evenNumbers, 
+                oddNumbers, 
+                (a, b) -> a + b);
+
+        StepVerifier.create(fluxOfIntegers)
+        .expectNext(5)
+        .expectNext(7)
+        .expectNext(9)
+        .expectComplete()
+        .verify();
+
+    }
+
+    @Test
+    public void testCombineLatest1() {
+            StepVerifier.create(Flux.combineLatest(obj -> (int) obj[1], evenNumbers, oddNumbers))
+            .expectNext(1)
+            .expectNext(3)
+            .expectNext(5)
+                        .verifyComplete();
+    }
+    
+    @Test
+    public void testMergeSequential() {
+        Flux<Integer> fluxOfIntegers = Flux.mergeSequential(
+                evenNumbers, 
+                oddNumbers);
+        
+        StepVerifier.create(fluxOfIntegers)
+        .expectNext(2)
+        .expectNext(4)
+        .expectNext(1)
+        .expectNext(3)
+        .expectNext(5)
+        .expectComplete()
+        .verify();
+    }
+    
+    
+    @Test
+    public void testMergeDelayError() {
+        Flux<Integer> fluxOfIntegers = Flux.mergeDelayError(1, 
+                evenNumbers.delayElements(Duration.ofMillis(500L)), 
+                oddNumbers.delayElements(Duration.ofMillis(300L)));
+        
+        StepVerifier.create(fluxOfIntegers)
+        .expectNext(1)
+        .expectNext(2)
+        .expectNext(3)
+        .expectNext(5)
+        .expectNext(4)
+        .expectComplete()
+        .verify();
+    }
+    
+    @Test
+    public void testMergeWith() {
+        Flux<Integer> fluxOfIntegers = evenNumbers.mergeWith(oddNumbers);
+        
+        StepVerifier.create(fluxOfIntegers)
+        .expectNext(2)
+        .expectNext(4)
+        .expectNext(1)
+        .expectNext(3)
+        .expectNext(5)
+        .expectComplete()
+        .verify();
+    }
+    
+    @Test
+    public void testZip() {
+        Flux<Integer> fluxOfIntegers = Flux.zip(
+                evenNumbers, 
+                oddNumbers, 
+                (a, b) -> a + b);
+        
+        StepVerifier.create(fluxOfIntegers)
+        .expectNext(3)
+        .expectNext(7)
+        .expectComplete()
+        .verify();
+    }
+    
+    @Test
+    public void testZipWith() {
+        Flux<Integer> fluxOfIntegers = evenNumbers
+                .zipWith(oddNumbers, 
+                (a, b) -> a * b);
+        
+        StepVerifier.create(fluxOfIntegers)
+        .expectNext(2)
+        .expectNext(12)
+        .expectComplete()
+        .verify();
+    }
+    
+    
+}
--- a/spring-cloud/spring-cloud-security/oauth2client/pom.xml
+++ b/spring-cloud/spring-cloud-security/oauth2client/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>oauth2client</artifactId>
+	<artifactId>auth-client</artifactId>
 	<version>0.0.1-SNAPSHOT</version>
 	<packaging>jar</packaging>

-	<name>oauth2client</name>
+	<name>auth-client</name>
 	<description>Demo project for Spring Boot</description>

 	<parent>
--- a/spring-cloud/spring-cloud-security/oauth2client/src/main/java/com/baeldung/CloudSite.java
+++ b/spring-cloud/spring-cloud-security/oauth2client/src/main/java/com/baeldung/CloudSite.java
--- a/spring-cloud/spring-cloud-security/oauth2client/src/main/java/com/baeldung/config/SiteSecurityConfigurer.java
+++ b/spring-cloud/spring-cloud-security/oauth2client/src/main/java/com/baeldung/config/SiteSecurityConfigurer.java
--- a/spring-cloud/spring-cloud-security/oauth2client/src/main/java/com/baeldung/controller/CloudSiteController.java
+++ b/spring-cloud/spring-cloud-security/oauth2client/src/main/java/com/baeldung/controller/CloudSiteController.java
--- a/spring-cloud/spring-cloud-security/oauth2client/src/main/java/com/baeldung/filters/SimpleFilter.java
+++ b/spring-cloud/spring-cloud-security/oauth2client/src/main/java/com/baeldung/filters/SimpleFilter.java
--- a/spring-cloud/spring-cloud-security/oauth2client/src/main/resources/application.properties
+++ b/spring-cloud/spring-cloud-security/oauth2client/src/main/resources/application.properties
--- a/spring-cloud/spring-cloud-security/oauth2client/src/main/resources/application.yml
+++ b/spring-cloud/spring-cloud-security/oauth2client/src/main/resources/application.yml
--- a/spring-cloud/spring-cloud-security/oauth2client/src/main/resources/templates/personinfo.html
+++ b/spring-cloud/spring-cloud-security/oauth2client/src/main/resources/templates/personinfo.html
--- a/spring-cloud/spring-cloud-security/oauth2client/src/test/java/com/example/springoath2/Springoath2ApplicationTests.java
+++ b/spring-cloud/spring-cloud-security/oauth2client/src/test/java/com/example/springoath2/Springoath2ApplicationTests.java
--- a/spring-cloud/spring-cloud-security/personresource/pom.xml
+++ b/spring-cloud/spring-cloud-security/personresource/pom.xml
@ -4,11 +4,11 @@
 	<modelVersion>4.0.0</modelVersion>

 	<groupId>com.baeldung</groupId>
-	<artifactId>personresource</artifactId>
+	<artifactId>auth-resource</artifactId>
 	<version>0.0.1-SNAPSHOT</version>
 	<packaging>jar</packaging>

-	<name>personresource</name>
+	<name>auth-resource</name>
 	<description>Demo project for Spring Boot</description>

 	<parent>
--- a/spring-cloud/spring-cloud-security/personresource/src/main/java/com/baeldung/Application.java
+++ b/spring-cloud/spring-cloud-security/personresource/src/main/java/com/baeldung/Application.java
--- a/spring-cloud/spring-cloud-security/personresource/src/main/java/com/baeldung/config/ResourceConfigurer.java
+++ b/spring-cloud/spring-cloud-security/personresource/src/main/java/com/baeldung/config/ResourceConfigurer.java
--- a/spring-cloud/spring-cloud-security/personresource/src/main/java/com/baeldung/controller/PersonInfoController.java
+++ b/spring-cloud/spring-cloud-security/personresource/src/main/java/com/baeldung/controller/PersonInfoController.java
--- a/spring-cloud/spring-cloud-security/personresource/src/main/java/com/baeldung/model/Person.java
+++ b/spring-cloud/spring-cloud-security/personresource/src/main/java/com/baeldung/model/Person.java
--- a/spring-cloud/spring-cloud-security/personresource/src/main/resources/application.yml
+++ b/spring-cloud/spring-cloud-security/personresource/src/main/resources/application.yml
--- a/spring-cloud/spring-cloud-security/personresource/src/test/java/com/baeldung/service/personservice/PersonserviceApplicationTests.java
+++ b/spring-cloud/spring-cloud-security/personresource/src/test/java/com/baeldung/service/personservice/PersonserviceApplicationTests.java
--- a/spring-cloud/spring-cloud-security/auth-server/pom.xml
+++ b/spring-cloud/spring-cloud-security/auth-server/pom.xml
@ -4,7 +4,7 @@
 	<modelVersion>4.0.0</modelVersion>

 	<groupId>com.baeldung</groupId>
-	<artifactId>authserver</artifactId>
+	<artifactId>auth-server</artifactId>
 	<version>0.0.1-SNAPSHOT</version>


--- a/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/AuthServer.java
+++ b/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/AuthServer.java
--- a/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/config/AuthServerConfigurer.java
+++ b/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/config/AuthServerConfigurer.java
--- a/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/config/ResourceServerConfigurer.java
+++ b/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/config/ResourceServerConfigurer.java
--- a/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/config/WebMvcConfigurer.java
+++ b/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/config/WebMvcConfigurer.java
--- a/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/config/WebSecurityConfigurer.java
+++ b/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/config/WebSecurityConfigurer.java
--- a/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/controller/ResourceController.java
+++ b/spring-cloud/spring-cloud-security/auth-server/src/main/java/com/baeldung/controller/ResourceController.java
--- a/spring-cloud/spring-cloud-security/auth-server/src/main/resources/application.yml
+++ b/spring-cloud/spring-cloud-security/auth-server/src/main/resources/application.yml
--- a/spring-cloud/spring-cloud-security/auth-server/src/main/resources/certificate/mykeystore.jks
+++ b/spring-cloud/spring-cloud-security/auth-server/src/main/resources/certificate/mykeystore.jks
--- a/spring-cloud/spring-cloud-security/auth-server/src/main/resources/templates/login.html
+++ b/spring-cloud/spring-cloud-security/auth-server/src/main/resources/templates/login.html
--- a/spring-data-spring-security/README.md
+++ b/spring-data-spring-security/README.md
@ -0,0 +1,14 @@
+# About this project
+This project contains examples from the [Spring Data with Spring Security](http://www.baeldung.com/spring-data-with-spring-security) article from Baeldung.
+
+# Running the project
+The application uses [Spring Boot](http://projects.spring.io/spring-boot/), so it is easy to run. You can start it any of a few ways:
+* Run the `main` method from `SpringDataRestApplication`
+* Use the Maven Spring Boot plugin: `mvn spring-boot:run`
+* Package the application as a JAR and run it using `java -jar spring-data-spring-security.jar`
+
+# Viewing the running application
+To view the running application, visit [http://localhost:8080](http://localhost:8080) in your browser
+
+###Relevant Articles:
+- [Spring Data with Spring Security](http://www.baeldung.com/spring-data-with-spring-security)
--- a/spring-data-spring-security/pom.xml
+++ b/spring-data-spring-security/pom.xml
@ -0,0 +1,67 @@
+<?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>spring-data-spring-security</artifactId>
+	<version>1.0</version>
+	<packaging>jar</packaging>
+
+	<name>intro-spring-data-spring-security</name>
+	<description>Spring Data with Spring Security</description>
+
+	<parent>
+		<artifactId>parent-boot-5</artifactId>
+		<groupId>com.baeldung</groupId>
+		<version>0.0.1-SNAPSHOT</version>
+		<relativePath>../parent-boot-5</relativePath>
+	</parent>
+
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-data-jpa</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.security</groupId>
+			<artifactId>spring-security-data</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-security</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.security</groupId>
+			<artifactId>spring-security-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+		<dependency>
+			<groupId>org.apache.tomcat.embed</groupId>
+			<artifactId>tomcat-embed-jasper</artifactId>
+			<!-- <scope>provided</scope> -->
+		</dependency>
+		<dependency>
+			<groupId>com.h2database</groupId>
+			<artifactId>h2</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>javax.servlet</groupId>
+			<artifactId>jstl</artifactId>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<finalName>${project.artifactId}</finalName>
+	</build>
+
+
+</project>
--- a/spring-data-spring-security/src/main/java/com/baeldung/AppConfig.java
+++ b/spring-data-spring-security/src/main/java/com/baeldung/AppConfig.java
@ -0,0 +1,64 @@
+package com.baeldung;
+
+import java.util.Properties;
+
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Import;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.jdbc.datasource.DriverManagerDataSource;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;
+
+@SpringBootApplication
+@PropertySource("classpath:persistence-h2.properties")
+@EnableJpaRepositories(basePackages = { "com.baeldung.data.repositories" })
+@EnableWebMvc
+@Import(SpringSecurityConfig.class)
+public class AppConfig extends WebMvcConfigurerAdapter {
+
+    @Autowired
+    private Environment env;
+
+    @Bean
+    public DataSource dataSource() {
+        final DriverManagerDataSource dataSource = new DriverManagerDataSource();
+        dataSource.setDriverClassName(env.getProperty("driverClassName"));
+        dataSource.setUrl(env.getProperty("url"));
+        dataSource.setUsername(env.getProperty("user"));
+        dataSource.setPassword(env.getProperty("password"));
+        return dataSource;
+    }
+
+    @Bean
+    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
+        final LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
+        em.setDataSource(dataSource());
+        em.setPackagesToScan(new String[] { "com.baeldung.models" });
+        em.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
+        em.setJpaProperties(additionalProperties());
+        return em;
+    }
+
+    final Properties additionalProperties() {
+        final Properties hibernateProperties = new Properties();
+        if (env.getProperty("hibernate.hbm2ddl.auto") != null) {
+            hibernateProperties.setProperty("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
+        }
+        if (env.getProperty("hibernate.dialect") != null) {
+            hibernateProperties.setProperty("hibernate.dialect", env.getProperty("hibernate.dialect"));
+        }
+        if (env.getProperty("hibernate.show_sql") != null) {
+            hibernateProperties.setProperty("hibernate.show_sql", env.getProperty("hibernate.show_sql"));
+        }
+        return hibernateProperties;
+    }
+
+}
--- a/spring-data-spring-security/src/main/java/com/baeldung/SpringSecurityConfig.java
+++ b/spring-data-spring-security/src/main/java/com/baeldung/SpringSecurityConfig.java
@ -0,0 +1,89 @@
+package com.baeldung;
+
+import javax.annotation.PostConstruct;
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.ComponentScan;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.security.authentication.dao.DaoAuthenticationProvider;
+import org.springframework.security.config.annotation.authentication.builders.AuthenticationManagerBuilder;
+import org.springframework.security.config.annotation.web.builders.HttpSecurity;
+import org.springframework.security.config.annotation.web.builders.WebSecurity;
+import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
+import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
+import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
+import org.springframework.security.crypto.password.PasswordEncoder;
+import org.springframework.security.data.repository.query.SecurityEvaluationContextExtension;
+import org.springframework.web.context.WebApplicationContext;
+
+import com.baeldung.security.AuthenticationSuccessHandlerImpl;
+import com.baeldung.security.CustomUserDetailsService;
+
+@Configuration
+@EnableWebSecurity
+@ComponentScan("com.baeldung.security")
+public class SpringSecurityConfig extends WebSecurityConfigurerAdapter {
+
+    @Autowired
+    private WebApplicationContext applicationContext;
+    private CustomUserDetailsService userDetailsService;
+    @Autowired
+    private AuthenticationSuccessHandlerImpl successHandler;
+    @Autowired
+    private DataSource dataSource;
+
+    @PostConstruct
+    public void completeSetup() {
+        userDetailsService = applicationContext.getBean(CustomUserDetailsService.class);
+    }
+
+    @Override
+    protected void configure(final AuthenticationManagerBuilder auth) throws Exception {
+        auth.userDetailsService(userDetailsService)
+            .passwordEncoder(encoder())
+            .and()
+            .authenticationProvider(authenticationProvider())
+            .jdbcAuthentication()
+            .dataSource(dataSource);
+    }
+
+    @Override
+    public void configure(WebSecurity web) throws Exception {
+        web.ignoring()
+            .antMatchers("/resources/**");
+    }
+
+    @Override
+    protected void configure(final HttpSecurity http) throws Exception {
+        http.authorizeRequests()
+            .antMatchers("/login")
+            .permitAll()
+            .and()
+            .formLogin()
+            .permitAll()
+            .successHandler(successHandler)
+            .and()
+            .csrf()
+            .disable();
+    }
+
+    @Bean
+    public DaoAuthenticationProvider authenticationProvider() {
+        final DaoAuthenticationProvider authProvider = new DaoAuthenticationProvider();
+        authProvider.setUserDetailsService(userDetailsService);
+        authProvider.setPasswordEncoder(encoder());
+        return authProvider;
+    }
+
+    @Bean
+    public PasswordEncoder encoder() {
+        return new BCryptPasswordEncoder(11);
+    }
+
+    @Bean
+    public SecurityEvaluationContextExtension securityEvaluationContextExtension() {
+        return new SecurityEvaluationContextExtension();
+    }
+}
--- a/spring-data-spring-security/src/main/java/com/baeldung/data/repositories/TweetRepository.java
+++ b/spring-data-spring-security/src/main/java/com/baeldung/data/repositories/TweetRepository.java
@ -0,0 +1,14 @@
+package com.baeldung.data.repositories;
+
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.PagingAndSortingRepository;
+
+import com.baeldung.models.Tweet;
+
+public interface TweetRepository extends PagingAndSortingRepository<Tweet, Long> {
+
+    @Query("select twt from Tweet twt  JOIN twt.likes as lk where lk = ?#{ principal?.username } or twt.owner = ?#{ principal?.username }")
+    Page<Tweet> getMyTweetsAndTheOnesILiked(Pageable pageable);
+}
--- a/spring-data-spring-security/src/main/java/com/baeldung/data/repositories/UserRepository.java
+++ b/spring-data-spring-security/src/main/java/com/baeldung/data/repositories/UserRepository.java
@ -0,0 +1,27 @@
+package com.baeldung.data.repositories;
+
+import java.util.Date;
+import java.util.List;
+
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.data.repository.query.Param;
+import org.springframework.stereotype.Repository;
+import org.springframework.transaction.annotation.Transactional;
+
+import com.baeldung.models.AppUser;
+import com.baeldung.models.Tweet;
+
+public interface UserRepository extends CrudRepository<AppUser, Long> {
+    AppUser findByUsername(String username);
+
+    List<AppUser> findByName(String name);
+
+    @Query("UPDATE AppUser u SET u.lastLogin=:lastLogin WHERE u.username = ?#{ principal?.username }")
+    @Modifying
+    @Transactional
+    public void updateLastLogin(@Param("lastLogin") Date lastLogin);
+}
--- a/spring-data-spring-security/src/main/java/com/baeldung/models/AppUser.java
+++ b/spring-data-spring-security/src/main/java/com/baeldung/models/AppUser.java
@ -0,0 +1,83 @@
+package com.baeldung.models;
+
+import java.util.Date;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "users")
+public class AppUser {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.SEQUENCE)
+    private long id;
+
+    private String name;
+    @Column(unique = true)
+    private String username;
+    private String password;
+    private boolean enabled = true;
+    private Date lastLogin;
+
+    private AppUser() {
+    }
+
+    public AppUser(String name, String email, String password) {
+        this.username = email;
+        this.name = name;
+        this.password = password;
+    }
+
+    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;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public void setUsername(String username) {
+        this.username = username;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public void setPassword(String password) {
+        this.password = password;
+    }
+
+    public boolean isEnabled() {
+        return enabled;
+    }
+
+    public void setEnabled(boolean enabled) {
+        this.enabled = enabled;
+    }
+
+    public Date getLastLogin() {
+        return lastLogin;
+    }
+
+    public void setLastLogin(Date lastLogin) {
+        this.lastLogin = lastLogin;
+    }
+}
--- a/spring-data-spring-security/src/main/java/com/baeldung/models/Tweet.java
+++ b/spring-data-spring-security/src/main/java/com/baeldung/models/Tweet.java
@ -0,0 +1,63 @@
+package com.baeldung.models;
+
+import java.util.HashSet;
+import java.util.Set;
+
+import javax.persistence.ElementCollection;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class Tweet {
+    @Id
+    @GeneratedValue(strategy = GenerationType.SEQUENCE)
+    private long id;
+    private String tweet;
+    private String owner;
+    @ElementCollection(targetClass = String.class, fetch = FetchType.EAGER)
+    private Set<String> likes = new HashSet();
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(long id) {
+        this.id = id;
+    }
+
+    private Tweet() {
+    }
+
+    public Tweet(String tweet, String owner) {
+        this.tweet = tweet;
+        this.owner = owner;
+    }
+
+    public String getTweet() {
+        return tweet;
+    }
+
+    public void setTweet(String tweet) {
+        this.tweet = tweet;
+    }
+
+    public String getOwner() {
+        return owner;
+    }
+
+    public void setOwner(String owner) {
+        this.owner = owner;
+    }
+
+    public Set<String> getLikes() {
+        return likes;
+    }
+
+    public void setLikes(Set<String> likes) {
+        this.likes = likes;
+    }
+
+}
--- a/spring-data-spring-security/src/main/java/com/baeldung/security/AppUserPrincipal.java
+++ b/spring-data-spring-security/src/main/java/com/baeldung/security/AppUserPrincipal.java
@ -0,0 +1,67 @@
+package com.baeldung.security;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.List;
+
+import org.springframework.security.core.GrantedAuthority;
+import org.springframework.security.core.authority.SimpleGrantedAuthority;
+import org.springframework.security.core.userdetails.UserDetails;
+
+import com.baeldung.models.AppUser;
+
+public class AppUserPrincipal implements UserDetails {
+
+    private final AppUser user;
+
+    //
+
+    public AppUserPrincipal(AppUser user) {
+        this.user = user;
+    }
+
+    //
+
+    @Override
+    public String getUsername() {
+        return user.getUsername();
+    }
+
+    @Override
+    public String getPassword() {
+        return user.getPassword();
+    }
+
+    @Override
+    public Collection<? extends GrantedAuthority> getAuthorities() {
+        final List<GrantedAuthority> authorities = Collections.singletonList(new SimpleGrantedAuthority("User"));
+        return authorities;
+    }
+
+    @Override
+    public boolean isAccountNonExpired() {
+        return true;
+    }
+
+    @Override
+    public boolean isAccountNonLocked() {
+        return true;
+    }
+
+    @Override
+    public boolean isCredentialsNonExpired() {
+        return true;
+    }
+
+    @Override
+    public boolean isEnabled() {
+        return true;
+    }
+
+    //
+
+    public AppUser getAppUser() {
+        return user;
+    }
+
+}
--- a/spring-data-spring-security/src/main/java/com/baeldung/security/AuthenticationSuccessHandlerImpl.java
+++ b/spring-data-spring-security/src/main/java/com/baeldung/security/AuthenticationSuccessHandlerImpl.java
@ -0,0 +1,28 @@
+package com.baeldung.security;
+
+import java.io.IOException;
+import java.util.Date;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.web.authentication.AuthenticationSuccessHandler;
+import org.springframework.stereotype.Component;
+
+import com.baeldung.data.repositories.UserRepository;
+
+@Component
+public class AuthenticationSuccessHandlerImpl implements AuthenticationSuccessHandler {
+
+    @Autowired
+    private UserRepository userRepository;
+
+    @Override
+    public void onAuthenticationSuccess(HttpServletRequest arg0, HttpServletResponse arg1, Authentication arg2) throws IOException, ServletException {
+        userRepository.updateLastLogin(new Date());
+    }
+
+}
--- a/spring-data-spring-security/src/main/java/com/baeldung/security/CustomUserDetailsService.java
+++ b/spring-data-spring-security/src/main/java/com/baeldung/security/CustomUserDetailsService.java
@ -0,0 +1,40 @@
+package com.baeldung.security;
+
+import javax.annotation.PostConstruct;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.security.core.userdetails.UserDetails;
+import org.springframework.security.core.userdetails.UserDetailsService;
+import org.springframework.security.core.userdetails.UsernameNotFoundException;
+import org.springframework.stereotype.Service;
+import org.springframework.web.context.WebApplicationContext;
+
+import com.baeldung.data.repositories.UserRepository;
+import com.baeldung.models.AppUser;
+
+@Service
+public class CustomUserDetailsService implements UserDetailsService {
+
+    @Autowired
+    private WebApplicationContext applicationContext;
+    private UserRepository userRepository;
+
+    public CustomUserDetailsService() {
+        super();
+    }
+
+    @PostConstruct
+    public void completeSetup() {
+        userRepository = applicationContext.getBean(UserRepository.class);
+    }
+
+    @Override
+    public UserDetails loadUserByUsername(final String username) {
+        final AppUser appUser = userRepository.findByUsername(username);
+        if (appUser == null) {
+            throw new UsernameNotFoundException(username);
+        }
+        return new AppUserPrincipal(appUser);
+    }
+
+}
--- a/spring-data-spring-security/src/main/java/com/baeldung/util/DummyContentUtil.java
+++ b/spring-data-spring-security/src/main/java/com/baeldung/util/DummyContentUtil.java
@ -0,0 +1,63 @@
+package com.baeldung.util;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+import java.util.Random;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+
+import org.springframework.security.core.GrantedAuthority;
+import org.springframework.security.crypto.bcrypt.BCryptPasswordEncoder;
+
+import com.baeldung.models.AppUser;
+import com.baeldung.models.Tweet;
+
+public class DummyContentUtil {
+    
+    public static final List<AppUser> generateDummyUsers() {
+        List<AppUser> appUsers = new ArrayList<>();
+        BCryptPasswordEncoder passwordEncoder = new BCryptPasswordEncoder();
+        appUsers.add(new AppUser("Lionel Messi", "lionel@messi.com", passwordEncoder.encode("li1234")));
+        appUsers.add(new AppUser("Cristiano Ronaldo", "cristiano@ronaldo.com", passwordEncoder.encode("c1234")));
+        appUsers.add(new AppUser("Neymar Dos Santos", "neymar@neymar.com", passwordEncoder.encode("n1234")));
+        appUsers.add(new AppUser("Luiz Suarez", "luiz@suarez.com", passwordEncoder.encode("lu1234")));
+        appUsers.add(new AppUser("Andres Iniesta", "andres@iniesta.com", passwordEncoder.encode("a1234")));
+        appUsers.add(new AppUser("Ivan Rakitic", "ivan@rakitic.com", passwordEncoder.encode("i1234")));
+        appUsers.add(new AppUser("Ousman Dembele", "ousman@dembele.com", passwordEncoder.encode("o1234")));
+        appUsers.add(new AppUser("Sergio Busquet", "sergio@busquet.com", passwordEncoder.encode("s1234")));
+        appUsers.add(new AppUser("Gerard Pique", "gerard@pique.com", passwordEncoder.encode("g1234")));
+        appUsers.add(new AppUser("Ter Stergen", "ter@stergen.com", passwordEncoder.encode("t1234")));
+        return appUsers;
+    }
+
+    public static final List<Tweet> generateDummyTweets(List<AppUser> users) {
+        List<Tweet> tweets = new ArrayList<>();
+        Random random = new Random();
+        IntStream.range(0, 9)
+            .sequential()
+            .forEach(i -> {
+                Tweet twt = new Tweet(String.format("Tweet %d", i), users.get(random.nextInt(users.size()))
+                    .getUsername());
+                twt.getLikes()
+                    .addAll(users.subList(0, random.nextInt(users.size()))
+                        .stream()
+                        .map(AppUser::getUsername)
+                        .collect(Collectors.toSet()));
+                tweets.add(twt);
+            });
+        return tweets;
+    }
+
+    public static Collection<GrantedAuthority> getAuthorities() {
+        Collection<GrantedAuthority> grantedAuthorities = new ArrayList<GrantedAuthority>();
+        GrantedAuthority grantedAuthority = new GrantedAuthority() {
+            public String getAuthority() {
+                return "ROLE_USER";
+            }
+        };
+        grantedAuthorities.add(grantedAuthority);
+        return grantedAuthorities;
+    }
+
+}
--- a/spring-data-spring-security/src/main/resources/application.properties
+++ b/spring-data-spring-security/src/main/resources/application.properties
--- a/Show More
+++ b/Show More