Merge pull request #2 from eugenp/master

Update from master

activejdbc/pom.xml

@@ -0,0 +1,129 @@
+<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>activejdbc</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+  <name>activejdbc</name>
+  <url>http://maven.apache.org</url>
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <activejdbc.version>1.4.13</activejdbc.version>
+    <environments>development.test,development</environments>
+  </properties>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-compiler-plugin</artifactId>
+        <version>3.6.0</version>
+        <configuration>
+          <source>1.8</source>
+          <target>1.8</target>
+          <encoding>UTF-8</encoding>
+        </configuration>
+      </plugin>
+      <plugin>
+        <groupId>org.javalite</groupId>
+        <artifactId>activejdbc-instrumentation</artifactId>
+        <version>${activejdbc.version}</version>
+        <executions>
+          <execution>
+            <phase>process-classes</phase>
+            <goals>
+              <goal>instrument</goal>
+            </goals>
+          </execution>
+        </executions>
+      </plugin>
+      <plugin>
+        <groupId>org.javalite</groupId>
+        <artifactId>db-migrator-maven-plugin</artifactId>
+        <version>${activejdbc.version}</version>
+        <configuration>
+          <configFile>${project.basedir}/src/main/resources/database.properties</configFile>
+          <environments>${environments}</environments>
+        </configuration>
+        <dependencies>
+          <dependency>
+            <groupId>mysql</groupId>
+            <artifactId>mysql-connector-java</artifactId>
+            <version>5.1.34</version>
+          </dependency>
+        </dependencies>
+      </plugin>
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>2.18.1</version>
+        <configuration>
+          <reportFormat>brief</reportFormat>
+          <trimStackTrace>true</trimStackTrace>
+          <useFile>false</useFile>
+          <includes>
+            <include>**/*Spec*.java</include>
+            <include>**/*Test*.java</include>
+          </includes>
+          <excludes>
+            <exclude>**/helpers/*</exclude>
+            <exclude>**/*$*</exclude>
+          </excludes>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.12</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.javalite</groupId>
+      <artifactId>activejdbc</artifactId>
+      <version>${activejdbc.version}</version>
+      <exclusions>
+        <exclusion>
+          <groupId>opensymphony</groupId>
+          <artifactId>oscache</artifactId>
+        </exclusion>
+      </exclusions>
+    </dependency>
+    <dependency>
+      <groupId>mysql</groupId>
+      <artifactId>mysql-connector-java</artifactId>
+      <version>5.1.34</version>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-simple</artifactId>
+      <version>1.7.9</version>
+    </dependency>
+  </dependencies>
+  <repositories>
+    <repository>
+      <id>snapshots1</id>
+      <name>JavaLite Snapshots1</name>
+      <url>http://repo.javalite.io/</url>
+      <snapshots>
+        <enabled>true</enabled>
+        <updatePolicy>always</updatePolicy>
+        <checksumPolicy>warn</checksumPolicy>
+      </snapshots>
+    </repository>
+  </repositories>
+  <pluginRepositories>
+    <pluginRepository>
+      <id>snapshots2</id>
+      <name>JavaLite Snapshots2</name>
+      <url>http://repo.javalite.io/</url>
+      <snapshots>
+        <enabled>true</enabled>
+        <updatePolicy>always</updatePolicy>
+        <checksumPolicy>warn</checksumPolicy>
+      </snapshots>
+    </pluginRepository>
+  </pluginRepositories>
+</project>

activejdbc/src/main/java/com/baeldung/ActiveJDBCApp.java

@@ -0,0 +1,61 @@
+package com.baeldung;
+
+
+import com.baeldung.model.Employee;
+import com.baeldung.model.Role;
+import org.javalite.activejdbc.Base;
+import org.javalite.activejdbc.LazyList;
+import org.javalite.activejdbc.Model;
+
+public class ActiveJDBCApp
+{
+    public static void main( String[] args )
+    {
+        try {
+            Base.open();
+            ActiveJDBCApp app = new ActiveJDBCApp();
+            app.create();
+            app.update();
+            app.delete();
+            app.deleteCascade();
+        } catch (Exception e) {
+            e.printStackTrace();
+        } finally {
+            Base.close();
+        }
+    }
+
+    protected void create() {
+        Employee employee = new Employee("Hugo","C","M","BN");
+        employee.saveIt();
+        employee.add(new Role("Java Developer","BN"));
+        LazyList<Model> all = Employee.findAll();
+        System.out.println(all.size());
+    }
+
+    protected void update() {
+        Employee employee = Employee.findFirst("first_name = ?","Hugo");
+        employee.set("last_namea","Choi").saveIt();
+        employee = Employee.findFirst("last_name = ?","Choi");
+        System.out.println(employee.getString("first_name") + " " + employee.getString("last_name"));
+    }
+
+    protected void delete() {
+        Employee employee = Employee.findFirst("first_name = ?","Hugo");
+        employee.delete();
+        employee = Employee.findFirst("last_name = ?","Choi");
+        if(null == employee){
+            System.out.println("No such Employee found!");
+        }
+    }
+
+    protected void deleteCascade() {
+        create();
+        Employee employee = Employee.findFirst("first_name = ?","Hugo");
+        employee.deleteCascade();
+        employee = Employee.findFirst("last_name = ?","C");
+        if(null == employee){
+            System.out.println("No such Employee found!");
+        }
+    }
+}

activejdbc/src/main/java/com/baeldung/model/Employee.java

@@ -0,0 +1,19 @@
+package com.baeldung.model;
+
+
+import org.javalite.activejdbc.Model;
+
+public class Employee extends Model {
+
+    public Employee(){
+
+    }
+
+    public Employee(String firstName, String lastName, String gender, String createdBy) {
+        set("first_name1",firstName);
+        set("last_name",lastName);
+        set("gender",gender);
+        set("created_by",createdBy);
+    }
+
+}

activejdbc/src/main/java/com/baeldung/model/Role.java

@@ -0,0 +1,18 @@
+package com.baeldung.model;
+
+
+import org.javalite.activejdbc.Model;
+import org.javalite.activejdbc.annotations.Table;
+
+@Table("EMP_ROLES")
+public class Role extends Model {
+
+    public Role(){
+
+    }
+
+    public Role(String role,String createdBy){
+        set("role_name",role);
+        set("created_by",createdBy);
+    }
+}

activejdbc/src/main/migration/_create_tables.sql

@@ -0,0 +1,25 @@
+# noinspection SqlNoDataSourceInspectionForFile
+
+create table organisation.employees
+(
+	id int not null auto_increment
+		primary key,
+	first_name varchar(100) not null,
+	last_name varchar(100) not null,
+	gender varchar(1) not null,
+	created_at datetime not null,
+	updated_at datetime null,
+	created_by varchar(100) not null,
+	updated_by varchar(100) null
+)ENGINE = InnoDB DEFAULT CHARSET = utf8;
+
+create table organisation.emp_roles
+(
+	id int not null auto_increment primary key,
+	employee_id int not null,
+	role_name varchar(100) not null,
+	created_at datetime not null,
+	updated_at datetime null,
+	created_by varchar(100) not null,
+	updated_by varchar(100) null
+)ENGINE = InnoDB DEFAULT CHARSET = utf8;

activejdbc/src/main/resources/database.properties

@@ -0,0 +1,10 @@
+development.driver=com.mysql.jdbc.Driver
+development.username=root
+development.password=123456
+development.url=jdbc:mysql://localhost/organisation
+
+
+development.test.driver=com.mysql.jdbc.Driver
+development.test.username=root
+development.test.password=123456
+development.test.url=jdbc:mysql://localhost/organisation_test

activejdbc/src/test/java/com/baeldung/ActiveJDBCAppTest.java

@@ -0,0 +1,51 @@
+package com.baeldung;
+
+import com.baeldung.model.Employee;
+import com.baeldung.model.Role;
+import org.javalite.activejdbc.test.DBSpec;
+import org.junit.Test;
+
+import java.util.List;
+
+public class ActiveJDBCAppTest extends DBSpec
+{
+    @Test
+    public void ifEmployeeCreated_thenIsValid() {
+        Employee employee = new Employee("B", "N", "M", "BN");
+        the(employee).shouldBe("valid");
+    }
+
+    @Test
+    public void ifEmployeeCreatedWithRoles_thenShouldPersist() {
+        Employee employee = new Employee("B", "N", "M", "BN");
+        employee.saveIt();
+        employee.add(new Role("Java Developer","BN"));
+        employee.add(new Role("Lead Java Developer","BN"));
+        a(Role.count()).shouldBeEqual(2);
+        List<Role> roles = employee.getAll(Role.class).orderBy("created_at");
+        the(roles.get(0).getRoleName()).shouldBeEqual("Java Developer");
+        the(roles.get(1).getRoleName()).shouldBeEqual("Lead Java Developer");
+    }
+
+    @Test
+    public void ifEmployeeCreatedWithRoles_whenNameUpdated_thenShouldShowNewName() {
+        Employee employee = new Employee("Binesh", "N", "M", "BN");
+        employee.saveIt();
+        employee.add(new Role("Java Developer","BN"));
+        employee.add(new Role("Lead Java Developer","BN"));
+        employee = Employee.findFirst("first_name = ?", "Binesh");
+        employee.set("last_name","Narayanan").saveIt();
+        Employee updated = Employee.findFirst("first_name = ?", "Binesh");
+        the(updated.getLastName()).shouldBeEqual("Narayanan");
+    }
+
+    @Test
+    public void ifEmployeeCreatedWithRoles_whenDeleted_thenShouldNotBeFound() {
+        Employee employee = new Employee("Binesh", "N", "M", "BN");
+        employee.saveIt();
+        employee.add(new Role("Java Developer","BN"));
+        employee.delete();
+        employee = Employee.findFirst("first_name = ?", "Binesh");
+        the(employee).shouldBeNull();
+    }
+}

algorithms/src/main/java/com/baeldung/algorithms/sudoku/BacktrackingAlgorithm.java

@@ -0,0 +1,104 @@
+package com.baeldung.algorithms.sudoku;
+
+import java.util.stream.IntStream;
+
+public class BacktrackingAlgorithm {
+
+    private static final int BOARD_SIZE = 9;
+    private static final int SUBSECTION_SIZE = 3;
+    private static final int BOARD_START_INDEX = 0;
+
+    private static final int NO_VALUE = 0;
+    private static final int MIN_VALUE = 1;
+    private static final int MAX_VALUE = 9;
+
+    private static int[][] board = {
+      {8, 0, 0, 0, 0, 0, 0, 0, 0},
+      {0, 0, 3, 6, 0, 0, 0, 0, 0},
+      {0, 7, 0, 0, 9, 0, 2, 0, 0},
+      {0, 5, 0, 0, 0, 7, 0, 0, 0},
+      {0, 0, 0, 0, 4, 5, 7, 0, 0},
+      {0, 0, 0, 1, 0, 0, 0, 3, 0},
+      {0, 0, 1, 0, 0, 0, 0, 6, 8},
+      {0, 0, 8, 5, 0, 0, 0, 1, 0},
+      {0, 9, 0, 0, 0, 0, 4, 0, 0}
+    };
+
+    public static void main(String[] args) {
+        BacktrackingAlgorithm solver = new BacktrackingAlgorithm();
+        solver.solve(board);
+        solver.printBoard();
+    }
+
+    private void printBoard() {
+        for (int row = BOARD_START_INDEX; row < BOARD_SIZE; row++) {
+            for (int column = BOARD_START_INDEX; column < BOARD_SIZE; column++) {
+                System.out.print(board[row][column] + " ");
+            }
+            System.out.println();
+        }
+    }
+
+    private boolean solve(int[][] board) {
+        for (int r = BOARD_START_INDEX; r < BOARD_SIZE; r++) {
+            for (int c = BOARD_START_INDEX; c < BOARD_SIZE; c++) {
+                if (board[r][c] == NO_VALUE) {
+                    for (int k = MIN_VALUE; k <= MAX_VALUE; k++) {
+                        board[r][c] = k;
+                        if (isValid(board, r, c) && solve(board)) {
+                            return true;
+                        }
+                        board[r][c] = NO_VALUE;
+                    }
+                    return false;
+                }
+            }
+        }
+        return true;
+    }
+
+    private boolean isValid(int[][] board, int r, int c) {
+        return rowConstraint(board, r) &&
+          columnConstraint(board, c) &&
+          subsectionConstraint(board, r, c);
+    }
+
+    private boolean subsectionConstraint(int[][] board, int r, int c) {
+        boolean[] constraint = new boolean[BOARD_SIZE];
+        int subsectionRowStart = (r / SUBSECTION_SIZE) * SUBSECTION_SIZE;
+        int subsectionRowEnd = subsectionRowStart + SUBSECTION_SIZE;
+
+        int subsectionColumnStart = (c / SUBSECTION_SIZE) * SUBSECTION_SIZE;
+        int subsectionColumnEnd = subsectionColumnStart + SUBSECTION_SIZE;
+
+        for (int i = subsectionRowStart; i < subsectionRowEnd; i++) {
+            for (int j = subsectionColumnStart; j < subsectionColumnEnd; j++) {
+                if (!checkConstraint(board, i, constraint, j)) return false;
+            }
+        }
+        return true;
+    }
+
+    private boolean columnConstraint(int[][] board, int c) {
+        boolean[] constraint = new boolean[BOARD_SIZE];
+        return IntStream.range(BOARD_START_INDEX, BOARD_SIZE)
+          .allMatch(i -> checkConstraint(board, i, constraint, c));
+    }
+
+    private boolean rowConstraint(int[][] board, int r) {
+        boolean[] constraint = new boolean[BOARD_SIZE];
+        return IntStream.range(BOARD_START_INDEX, BOARD_SIZE)
+          .allMatch(i -> checkConstraint(board, r, constraint, i));
+    }
+
+    private boolean checkConstraint(int[][] board, int r, boolean[] constraint, int c) {
+        if (board[r][c] != NO_VALUE) {
+            if (!constraint[board[r][c] - 1]) {
+                constraint[board[r][c] - 1] = true;
+            } else {
+                return false;
+            }
+        }
+        return true;
+    }
+}

algorithms/src/main/java/com/baeldung/algorithms/sudoku/ColumnNode.java

@@ -0,0 +1,33 @@
+package com.baeldung.algorithms.sudoku;
+
+class ColumnNode extends DancingNode {
+    int size;
+    String name;
+
+    ColumnNode(String n) {
+        super();
+        size = 0;
+        name = n;
+        C = this;
+    }
+
+    void cover() {
+        unlinkLR();
+        for (DancingNode i = this.D; i != this; i = i.D) {
+            for (DancingNode j = i.R; j != i; j = j.R) {
+                j.unlinkUD();
+                j.C.size--;
+            }
+        }
+    }
+
+    void uncover() {
+        for (DancingNode i = this.U; i != this; i = i.U) {
+            for (DancingNode j = i.L; j != i; j = j.L) {
+                j.C.size++;
+                j.relinkUD();
+            }
+        }
+        relinkLR();
+    }
+}

algorithms/src/main/java/com/baeldung/algorithms/sudoku/DancingLinks.java

@@ -0,0 +1,133 @@
+package com.baeldung.algorithms.sudoku;
+
+import java.util.ArrayList;
+import java.util.LinkedList;
+import java.util.List;
+
+public class DancingLinks {
+
+    private ColumnNode header;
+    private List<DancingNode> answer;
+
+    private void search(int k) {
+        if (header.R == header) {
+            handleSolution(answer);
+        } else {
+            ColumnNode c = selectColumnNodeHeuristic();
+            c.cover();
+
+            for (DancingNode r = c.D; r != c; r = r.D) {
+                answer.add(r);
+
+                for (DancingNode j = r.R; j != r; j = j.R) {
+                    j.C.cover();
+                }
+
+                search(k + 1);
+
+                r = answer.remove(answer.size() - 1);
+                c = r.C;
+
+                for (DancingNode j = r.L; j != r; j = j.L) {
+                    j.C.uncover();
+                }
+            }
+            c.uncover();
+        }
+    }
+
+    private ColumnNode selectColumnNodeHeuristic() {
+        int min = Integer.MAX_VALUE;
+        ColumnNode ret = null;
+        for (ColumnNode c = (ColumnNode) header.R; c != header; c = (ColumnNode) c.R) {
+            if (c.size < min) {
+                min = c.size;
+                ret = c;
+            }
+        }
+        return ret;
+    }
+
+    private ColumnNode makeDLXBoard(boolean[][] grid) {
+        final int COLS = grid[0].length;
+
+        ColumnNode headerNode = new ColumnNode("header");
+        List<ColumnNode> columnNodes = new ArrayList<>();
+
+        for (int i = 0; i < COLS; i++) {
+            ColumnNode n = new ColumnNode(Integer.toString(i));
+            columnNodes.add(n);
+            headerNode = (ColumnNode) headerNode.hookRight(n);
+        }
+        headerNode = headerNode.R.C;
+
+        for (boolean[] aGrid : grid) {
+            DancingNode prev = null;
+            for (int j = 0; j < COLS; j++) {
+                if (aGrid[j]) {
+                    ColumnNode col = columnNodes.get(j);
+                    DancingNode newNode = new DancingNode(col);
+                    if (prev == null)
+                        prev = newNode;
+                    col.U.hookDown(newNode);
+                    prev = prev.hookRight(newNode);
+                    col.size++;
+                }
+            }
+        }
+
+        headerNode.size = COLS;
+
+        return headerNode;
+    }
+
+    DancingLinks(boolean[][] cover) {
+        header = makeDLXBoard(cover);
+    }
+
+    public void runSolver() {
+        answer = new LinkedList<>();
+        search(0);
+    }
+
+    private void handleSolution(List<DancingNode> answer) {
+        int[][] result = parseBoard(answer);
+        printSolution(result);
+    }
+
+    private int size = 9;
+
+    private int[][] parseBoard(List<DancingNode> answer) {
+        int[][] result = new int[size][size];
+        for (DancingNode n : answer) {
+            DancingNode rcNode = n;
+            int min = Integer.parseInt(rcNode.C.name);
+            for (DancingNode tmp = n.R; tmp != n; tmp = tmp.R) {
+                int val = Integer.parseInt(tmp.C.name);
+                if (val < min) {
+                    min = val;
+                    rcNode = tmp;
+                }
+            }
+            int ans1 = Integer.parseInt(rcNode.C.name);
+            int ans2 = Integer.parseInt(rcNode.R.C.name);
+            int r = ans1 / size;
+            int c = ans1 % size;
+            int num = (ans2 % size) + 1;
+            result[r][c] = num;
+        }
+        return result;
+    }
+
+    private static void printSolution(int[][] result) {
+        int N = result.length;
+        for (int[] aResult : result) {
+            StringBuilder ret = new StringBuilder();
+            for (int j = 0; j < N; j++) {
+                ret.append(aResult[j]).append(" ");
+            }
+            System.out.println(ret);
+        }
+        System.out.println();
+    }
+}

algorithms/src/main/java/com/baeldung/algorithms/sudoku/DancingLinksAlgorithm.java

@@ -0,0 +1,108 @@
+package com.baeldung.algorithms.sudoku;
+
+import java.util.Arrays;
+
+public class DancingLinksAlgorithm {
+    private static final int BOARD_SIZE = 9;
+    private static final int SUBSECTION_SIZE = 3;
+    private static final int NO_VALUE = 0;
+    private static final int CONSTRAINTS = 4;
+    private static final int MIN_VALUE = 1;
+    private static final int MAX_VALUE = 9;
+    private static final int COVER_START_INDEX = 1;
+
+    private static int[][] board = {
+      {8, 0, 0, 0, 0, 0, 0, 0, 0},
+      {0, 0, 3, 6, 0, 0, 0, 0, 0},
+      {0, 7, 0, 0, 9, 0, 2, 0, 0},
+      {0, 5, 0, 0, 0, 7, 0, 0, 0},
+      {0, 0, 0, 0, 4, 5, 7, 0, 0},
+      {0, 0, 0, 1, 0, 0, 0, 3, 0},
+      {0, 0, 1, 0, 0, 0, 0, 6, 8},
+      {0, 0, 8, 5, 0, 0, 0, 1, 0},
+      {0, 9, 0, 0, 0, 0, 4, 0, 0}
+    };
+
+    public static void main(String[] args) {
+        DancingLinksAlgorithm solver = new DancingLinksAlgorithm();
+        solver.solve(board);
+    }
+
+    private void solve(int[][] board) {
+        boolean[][] cover = initializeExactCoverBoard(board);
+        DancingLinks dlx = new DancingLinks(cover);
+        dlx.runSolver();
+    }
+
+    private int getIndex(int row, int col, int num) {
+        return (row - 1) * BOARD_SIZE * BOARD_SIZE + (col - 1) * BOARD_SIZE + (num - 1);
+    }
+
+    private boolean[][] createExactCoverBoard() {
+        boolean[][] R = new boolean[BOARD_SIZE * BOARD_SIZE * MAX_VALUE][BOARD_SIZE * BOARD_SIZE * CONSTRAINTS];
+
+        int hBase = 0;
+
+        // 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
+        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;
+                        }
+                    }
+                }
+            }
+        }
+        return R;
+    }
+
+    private boolean[][] initializeExactCoverBoard(int[][] board) {
+        boolean[][] R = 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);
+                        }
+                    }
+                }
+            }
+        }
+        return R;
+    }
+}

algorithms/src/main/java/com/baeldung/algorithms/sudoku/DancingNode.java

@@ -0,0 +1,50 @@
+package com.baeldung.algorithms.sudoku;
+
+class DancingNode {
+    DancingNode L, R, U, D;
+    ColumnNode C;
+
+    DancingNode hookDown(DancingNode n1) {
+        assert (this.C == n1.C);
+        n1.D = this.D;
+        n1.D.U = n1;
+        n1.U = this;
+        this.D = n1;
+        return n1;
+    }
+
+    DancingNode hookRight(DancingNode n1) {
+        n1.R = this.R;
+        n1.R.L = n1;
+        n1.L = this;
+        this.R = n1;
+        return n1;
+    }
+
+    void unlinkLR() {
+        this.L.R = this.R;
+        this.R.L = this.L;
+    }
+
+    void relinkLR() {
+        this.L.R = this.R.L = this;
+    }
+
+    void unlinkUD() {
+        this.U.D = this.D;
+        this.D.U = this.U;
+    }
+
+    void relinkUD() {
+        this.U.D = this.D.U = this;
+    }
+
+    DancingNode() {
+        L = R = U = D = this;
+    }
+
+    DancingNode(ColumnNode c) {
+        this();
+        C = c;
+    }
+}

core-java-8/src/main/java/com/baeldung/spliteratorAPI/Executor.java

@@ -1,45 +1,19 @@
 package com.baeldung.spliteratorAPI;
 
-import java.util.Arrays;
 import java.util.List;
-import java.util.Spliterator;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
 import java.util.stream.Collectors;
-import java.util.stream.IntStream;
 import java.util.stream.Stream;
-import java.util.stream.StreamSupport;
 
 public class Executor {
-	public void executeCustomSpliterator() {
-        Article article = new Article(Arrays.asList(new Author("Ahmad", 0), new Author("Eugen", 0), new Author("Alice", 1), new Author("Alice", 1), new Author("Mike", 0), new Author("Alice", 1), new Author("Mike", 0), new Author("Alice", 1),
-            new Author("Mike", 0), new Author("Alice", 1), new Author("Mike", 0), new Author("Mike", 0), new Author("Alice", 1), new Author("Mike", 0), new Author("Alice", 1), new Author("Mike", 0), new Author("Alice", 1), new Author("Mike", 0),
-            new Author("Alice", 1), new Author("Mike", 0), new Author("Michał", 0), new Author("Loredana", 1)), 0);
-        Stream<Author> stream = IntStream.range(0, article.getListOfAuthors()
-            .size())
-            .mapToObj(article.getListOfAuthors()::get);
-        System.out.println("count= " + countAutors(stream.parallel()));
-        Spliterator<Author> spliterator = new RelatedAuthorSpliterator(article.getListOfAuthors());
-        Stream<Author> stream2 = StreamSupport.stream(spliterator, true);
-        System.out.println("count= " + countAutors(stream2.parallel()));
-    }
 
-    public void executeSpliterator() {
-        Spliterator<Article> split1 = generateElements().spliterator();
-        Spliterator<Article> split2 = split1.trySplit();
-        ExecutorService service = Executors.newCachedThreadPool();
-        service.execute(new Task(split1));
-        service.execute(new Task(split2));
-    }
+	public static int countAutors(Stream<Author> stream) {
+		RelatedAuthorCounter wordCounter = stream.reduce(new RelatedAuthorCounter(0, true),
+				RelatedAuthorCounter::accumulate, RelatedAuthorCounter::combine);
+		return wordCounter.getCounter();
+	}
 
-    private static int countAutors(Stream<Author> stream) {
-        RelatedAuthorCounter wordCounter = stream.reduce(new RelatedAuthorCounter(0, true), RelatedAuthorCounter::accumulate, RelatedAuthorCounter::combine);
-        return wordCounter.getCounter();
-    }
+	public static List<Article> generateElements() {
+		return Stream.generate(() -> new Article("Java")).limit(35000).collect(Collectors.toList());
+	}
 
-    private List<Article> generateElements() {
-        return Stream.generate(() -> new Article("Java"))
-            .limit(35000)
-            .collect(Collectors.toList());
-    }
-}
+}

core-java-8/src/main/java/com/baeldung/spliteratorAPI/RelatedAuthorSpliterator.java

@@ -2,46 +2,48 @@ package com.baeldung.spliteratorAPI;
 
 import java.util.List;
 import java.util.Spliterator;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
 
 public class RelatedAuthorSpliterator implements Spliterator<Author> {
-    private final List<Author> list;
-    private int current = 0;
+	private final List<Author> list;
+	AtomicInteger current = new AtomicInteger();
 
-    public RelatedAuthorSpliterator(List<Author> list) {
-        this.list = list;
-    }
+	public RelatedAuthorSpliterator(List<Author> list) {
+		this.list = list;
+	}
 
-    @Override
-    public boolean tryAdvance(Consumer<? super Author> action) {
-        action.accept(list.get(current++));
-        return current < list.size();
-    }
+	@Override
+	public boolean tryAdvance(Consumer<? super Author> action) {
 
-    @Override
-    public Spliterator<Author> trySplit() {
-        int currentSize = list.size() - current;
-        if (currentSize < 10) {
-            return null;
-        }
-        for (int splitPos = currentSize / 2 + current; splitPos < list.size(); splitPos++) {
-            if (list.get(splitPos)
-                .getRelatedArticleId() == 0) {
-                Spliterator<Author> spliterator = new RelatedAuthorSpliterator(list.subList(current, splitPos));
-                current = splitPos;
-                return spliterator;
-            }
-        }
-        return null;
-    }
+		action.accept(list.get(current.getAndIncrement()));
+		return current.get() < list.size();
+	}
 
-    @Override
-    public long estimateSize() {
-        return list.size() - current;
-    }
+	@Override
+	public Spliterator<Author> trySplit() {
+		int currentSize = list.size() - current.get();
+		if (currentSize < 10) {
+			return null;
+		}
+		for (int splitPos = currentSize / 2 + current.intValue(); splitPos < list.size(); splitPos++) {
+			if (list.get(splitPos).getRelatedArticleId() == 0) {
+				Spliterator<Author> spliterator = new RelatedAuthorSpliterator(list.subList(current.get(), splitPos));
+				current.set(splitPos);
+				return spliterator;
+			}
+		}
+		return null;
+	}
+
+	@Override
+	public long estimateSize() {
+		return list.size() - current.get();
+	}
+
+	@Override
+	public int characteristics() {
+		return CONCURRENT;
+	}
 
-    @Override
-    public int characteristics() {
-        return SIZED + CONCURRENT;
-    }
 }

core-java-8/src/main/java/com/baeldung/spliteratorAPI/Task.java

@@ -1,8 +1,9 @@
 package com.baeldung.spliteratorAPI;
 
 import java.util.Spliterator;
+import java.util.concurrent.Callable;
 
-public class Task implements Runnable {
+public class Task implements Callable<String> {
     private Spliterator<Article> spliterator;
     private final static String SUFFIX = "- published by Baeldung";
 
@@ -11,7 +12,7 @@ public class Task implements Runnable {
     }
 
     @Override
-    public void run() {
+    public String call() {
         int current = 0;
         while (spliterator.tryAdvance(article -> {
             article.setName(article.getName()
@@ -20,7 +21,7 @@ public class Task implements Runnable {
             current++;
         }
         ;
-        System.out.println(Thread.currentThread()
-            .getName() + ":" + current);
+        return Thread.currentThread()
+            .getName() + ":" + current;
     }
 }

core-java-8/src/test/java/com/baeldung/spliteratorAPI/ExecutorTest.java

@@ -0,0 +1,44 @@
+package com.baeldung.spliteratorAPI;
+
+import java.util.Arrays;
+import java.util.Spliterator;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+
+import static org.assertj.core.api.Assertions.*;
+import org.junit.Before;
+import org.junit.Test;
+
+public class ExecutorTest {
+	Article article;
+	Stream<Author> stream;
+	Spliterator<Author> spliterator;
+	Spliterator<Article> split1;
+	Spliterator<Article> split2;
+
+	@Before
+	public void init() {
+		article = new Article(Arrays.asList(new Author("Ahmad", 0), new Author("Eugen", 0), new Author("Alice", 1),
+				new Author("Alice", 1), new Author("Mike", 0), new Author("Alice", 1), new Author("Mike", 0),
+				new Author("Alice", 1), new Author("Mike", 0), new Author("Alice", 1), new Author("Mike", 0),
+				new Author("Mike", 0), new Author("Alice", 1), new Author("Mike", 0), new Author("Alice", 1),
+				new Author("Mike", 0), new Author("Alice", 1), new Author("Mike", 0), new Author("Alice", 1),
+				new Author("Mike", 0), new Author("Michał", 0), new Author("Loredana", 1)), 0);
+		stream = article.getListOfAuthors().stream();
+		split1 = Executor.generateElements().spliterator();
+		split2 = split1.trySplit();
+		spliterator = new RelatedAuthorSpliterator(article.getListOfAuthors());
+	}
+
+	@Test
+	public void givenAstreamOfAuthors_whenProcessedInParallelWithCustomSpliterator_coubtProducessRightOutput() {
+		Stream<Author> stream2 = StreamSupport.stream(spliterator, true);
+		assertThat(Executor.countAutors(stream2.parallel())).isEqualTo(9);
+	}
+
+	@Test
+	public void givenSpliterator_whenAppliedToAListOfArticle_thenSplittedInHalf() {
+		assertThat(new Task(split1).call()).containsSequence(Executor.generateElements().size() / 2 + "");
+		assertThat(new Task(split2).call()).containsSequence(Executor.generateElements().size() / 2 + "");
+	}
+}

core-java-9/src/test/java/com/baeldung/java9/httpclient/HttpClientTest.java

@@ -0,0 +1,218 @@
+package com.baeldung.java9.httpclient;
+
+import jdk.incubator.http.HttpClient;
+import jdk.incubator.http.HttpRequest;
+import jdk.incubator.http.HttpResponse;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.net.*;
+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;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.collection.IsEmptyCollection.empty;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Created by adam.
+ */
+public class HttpClientTest {
+
+    @Test
+    public void shouldReturnSampleDataContentWhenConnectViaSystemProxy() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/post"))
+            .headers("Content-Type", "text/plain;charset=UTF-8")
+            .POST(HttpRequest.BodyProcessor.fromString("Sample body"))
+            .build();
+
+        HttpResponse<String> response = HttpClient.newBuilder()
+            .proxy(ProxySelector.getDefault())
+            .build()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+        assertThat(response.body(), containsString("Sample body"));
+    }
+
+    @Test
+    public void shouldNotFollowRedirectWhenSetToDefaultNever() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("http://stackoverflow.com"))
+            .version(HttpClient.Version.HTTP_1_1)
+            .GET()
+            .build();
+        HttpResponse<String> response = HttpClient.newBuilder()
+            .build()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_MOVED_PERM));
+        assertThat(response.body(), containsString("https://stackoverflow.com/"));
+    }
+
+    @Test
+    public void shouldFollowRedirectWhenSetToAlways() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("http://stackoverflow.com"))
+            .version(HttpClient.Version.HTTP_1_1)
+            .GET()
+            .build();
+        HttpResponse<String> response = HttpClient.newBuilder()
+            .followRedirects(HttpClient.Redirect.ALWAYS)
+            .build()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+        assertThat(response.finalRequest()
+            .uri()
+            .toString(), equalTo("https://stackoverflow.com/"));
+    }
+
+    @Test
+    public void shouldReturnOKStatusForAuthenticatedAccess() throws URISyntaxException, IOException, InterruptedException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/basic-auth"))
+            .GET()
+            .build();
+        HttpResponse<String> response = HttpClient.newBuilder()
+            .authenticator(new Authenticator() {
+                @Override
+                protected PasswordAuthentication getPasswordAuthentication() {
+                    return new PasswordAuthentication("postman", "password".toCharArray());
+                }
+            })
+            .build()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+    }
+
+    @Test
+    public void shouldSendRequestAsync() throws URISyntaxException, InterruptedException, ExecutionException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/post"))
+            .headers("Content-Type", "text/plain;charset=UTF-8")
+            .POST(HttpRequest.BodyProcessor.fromString("Sample body"))
+            .build();
+        CompletableFuture<HttpResponse<String>> response = HttpClient.newBuilder()
+            .build()
+            .sendAsync(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.get()
+            .statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+    }
+
+    @Test
+    public void shouldUseJustTwoThreadWhenProcessingSendAsyncRequest() throws URISyntaxException, InterruptedException, ExecutionException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/get"))
+            .GET()
+            .build();
+
+        ExecutorService executorService = Executors.newFixedThreadPool(2);
+
+        CompletableFuture<HttpResponse<String>> response1 = HttpClient.newBuilder()
+            .executor(executorService)
+            .build()
+            .sendAsync(request, HttpResponse.BodyHandler.asString());
+
+        CompletableFuture<HttpResponse<String>> response2 = HttpClient.newBuilder()
+            .executor(executorService)
+            .build()
+            .sendAsync(request, HttpResponse.BodyHandler.asString());
+
+        CompletableFuture<HttpResponse<String>> response3 = HttpClient.newBuilder()
+            .executor(executorService)
+            .build()
+            .sendAsync(request, HttpResponse.BodyHandler.asString());
+
+        CompletableFuture.allOf(response1, response2, response3)
+            .join();
+
+        assertThat(response1.get()
+            .statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+        assertThat(response2.get()
+            .statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+        assertThat(response3.get()
+            .statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+    }
+
+    @Test
+    public void shouldNotStoreCookieWhenPolicyAcceptNone() throws URISyntaxException, IOException, InterruptedException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/get"))
+            .GET()
+            .build();
+
+        HttpClient httpClient = HttpClient.newBuilder()
+            .cookieManager(new CookieManager(null, CookiePolicy.ACCEPT_NONE))
+            .build();
+
+        httpClient.send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(httpClient.cookieManager()
+            .get()
+            .getCookieStore()
+            .getCookies(), empty());
+    }
+
+    @Test
+    public void shouldStoreCookieWhenPolicyAcceptAll() throws URISyntaxException, IOException, InterruptedException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/get"))
+            .GET()
+            .build();
+
+        HttpClient httpClient = HttpClient.newBuilder()
+            .cookieManager(new CookieManager(null, CookiePolicy.ACCEPT_ALL))
+            .build();
+
+        httpClient.send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(httpClient.cookieManager()
+            .get()
+            .getCookieStore()
+            .getCookies(), not(empty()));
+    }
+
+    @Test
+    public void shouldProcessMultipleRequestViaStream() throws URISyntaxException, ExecutionException, InterruptedException {
+        List<URI> targets = Arrays.asList(new URI("https://postman-echo.com/get?foo1=bar1"), new URI("https://postman-echo.com/get?foo2=bar2"));
+
+        HttpClient client = HttpClient.newHttpClient();
+
+        List<CompletableFuture<String>> futures = targets.stream()
+            .map(target -> client.sendAsync(HttpRequest.newBuilder(target)
+                .GET()
+                .build(), HttpResponse.BodyHandler.asString())
+                .thenApply(response -> response.body()))
+            .collect(Collectors.toList());
+
+        CompletableFuture.allOf(futures.toArray(new CompletableFuture[0]))
+            .join();
+
+        if (futures.get(0)
+            .get()
+            .contains("foo1")) {
+            assertThat(futures.get(0)
+                .get(), containsString("bar1"));
+            assertThat(futures.get(1)
+                .get(), containsString("bar2"));
+        } else {
+            assertThat(futures.get(1)
+                .get(), containsString("bar2"));
+            assertThat(futures.get(1)
+                .get(), containsString("bar1"));
+        }
+
+    }
+
+}

core-java-9/src/test/java/com/baeldung/java9/httpclient/HttpRequestTest.java

@@ -0,0 +1,171 @@
+package com.baeldung.java9.httpclient;
+
+import jdk.incubator.http.HttpClient;
+import jdk.incubator.http.HttpRequest;
+import jdk.incubator.http.HttpResponse;
+import org.junit.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.URI;
+import java.net.URISyntaxException;
+import java.nio.file.Paths;
+import java.security.NoSuchAlgorithmException;
+import java.time.Duration;
+
+import static java.time.temporal.ChronoUnit.SECONDS;
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Created by adam.
+ */
+public class HttpRequestTest {
+
+    @Test
+    public void shouldReturnStatusOKWhenSendGetRequest() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/get"))
+            .GET()
+            .build();
+
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+    }
+
+    @Test
+    public void shouldUseHttp2WhenWebsiteUsesHttp2() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://stackoverflow.com"))
+            .version(HttpClient.Version.HTTP_2)
+            .GET()
+            .build();
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+        assertThat(response.version(), equalTo(HttpClient.Version.HTTP_2));
+    }
+
+    @Test
+    public void shouldFallbackToHttp1_1WhenWebsiteDoesNotUseHttp2() throws IOException, InterruptedException, URISyntaxException, NoSuchAlgorithmException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/get"))
+            .version(HttpClient.Version.HTTP_2)
+            .GET()
+            .build();
+
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.version(), equalTo(HttpClient.Version.HTTP_1_1));
+    }
+
+    @Test
+    public void shouldReturnStatusOKWhenSendGetRequestWithDummyHeaders() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/get"))
+            .headers("key1", "value1", "key2", "value2")
+            .GET()
+            .build();
+
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+    }
+
+    @Test
+    public void shouldReturnStatusOKWhenSendGetRequestTimeoutSet() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/get"))
+            .timeout(Duration.of(10, SECONDS))
+            .GET()
+            .build();
+
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+    }
+
+    @Test
+    public void shouldReturnNoContentWhenPostWithNoBody() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/post"))
+            .POST(HttpRequest.noBody())
+            .build();
+
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+    }
+
+    @Test
+    public void shouldReturnSampleDataContentWhenPostWithBodyText() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/post"))
+            .headers("Content-Type", "text/plain;charset=UTF-8")
+            .POST(HttpRequest.BodyProcessor.fromString("Sample request body"))
+            .build();
+
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+        assertThat(response.body(), containsString("Sample request body"));
+    }
+
+    @Test
+    public void shouldReturnSampleDataContentWhenPostWithInputStream() throws IOException, InterruptedException, URISyntaxException {
+        byte[] sampleData = "Sample request body".getBytes();
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/post"))
+            .headers("Content-Type", "text/plain;charset=UTF-8")
+            .POST(HttpRequest.BodyProcessor.fromInputStream(() -> new ByteArrayInputStream(sampleData)))
+            .build();
+
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+        assertThat(response.body(), containsString("Sample request body"));
+    }
+
+    @Test
+    public void shouldReturnSampleDataContentWhenPostWithByteArrayProcessorStream() throws IOException, InterruptedException, URISyntaxException {
+        byte[] sampleData = "Sample request body".getBytes();
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/post"))
+            .headers("Content-Type", "text/plain;charset=UTF-8")
+            .POST(HttpRequest.BodyProcessor.fromByteArray(sampleData))
+            .build();
+
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+        assertThat(response.body(), containsString("Sample request body"));
+    }
+
+    @Test
+    public void shouldReturnSampleDataContentWhenPostWithFileProcessorStream() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/post"))
+            .headers("Content-Type", "text/plain;charset=UTF-8")
+            .POST(HttpRequest.BodyProcessor.fromFile(Paths.get("src/test/resources/sample.txt")))
+            .build();
+
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+        assertThat(response.body(), containsString("Sample file content"));
+    }
+
+}

core-java-9/src/test/java/com/baeldung/java9/httpclient/HttpResponseTest.java

@@ -0,0 +1,55 @@
+package com.baeldung.java9.httpclient;
+
+import jdk.incubator.http.HttpClient;
+import jdk.incubator.http.HttpRequest;
+import jdk.incubator.http.HttpResponse;
+import org.junit.Test;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.URI;
+import java.net.URISyntaxException;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.Matchers.isEmptyString;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertThat;
+
+/**
+ * Created by adam.
+ */
+public class HttpResponseTest {
+
+    @Test
+    public void shouldReturnStatusOKWhenSendGetRequest() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("https://postman-echo.com/get"))
+            .GET()
+            .build();
+
+        HttpResponse<String> response = HttpClient.newHttpClient()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(response.statusCode(), equalTo(HttpURLConnection.HTTP_OK));
+        assertThat(response.body(), not(isEmptyString()));
+    }
+
+    @Test
+    public void shouldResponseURIDifferentThanRequestUIRWhenRedirect() throws IOException, InterruptedException, URISyntaxException {
+        HttpRequest request = HttpRequest.newBuilder()
+            .uri(new URI("http://stackoverflow.com"))
+            .version(HttpClient.Version.HTTP_1_1)
+            .GET()
+            .build();
+        HttpResponse<String> response = HttpClient.newBuilder()
+            .followRedirects(HttpClient.Redirect.ALWAYS)
+            .build()
+            .send(request, HttpResponse.BodyHandler.asString());
+
+        assertThat(request.uri()
+            .toString(), equalTo("http://stackoverflow.com"));
+        assertThat(response.uri()
+            .toString(), equalTo("https://stackoverflow.com/"));
+    }
+
+}

core-java-concurrency/README.md

@@ -33,4 +33,4 @@
 - [Daemon Threads in Java](http://www.baeldung.com/java-daemon-thread)
 - [Implementing a Runnable vs Extending a Thread](http://www.baeldung.com/java-runnable-vs-extending-thread)
 - [How to Kill a Java Thread](http://www.baeldung.com/java-thread-stop)
-- [How to Wait for Threads to Finish in the ExecutorService](http://www.baeldung.com/java-executor-wait-for-threads)
+- [ExecutorService - Waiting for Threads to Finish](http://www.baeldung.com/java-executor-wait-for-threads)

core-java-concurrency/src/main/java/com/baeldung/concurrent/prioritytaskexecution/Job.java

@@ -0,0 +1,24 @@
+package com.baeldung.concurrent.prioritytaskexecution;
+
+public class Job implements Runnable {
+    private String jobName;
+    private JobPriority jobPriority;
+    
+    public Job(String jobName, JobPriority jobPriority) {
+        this.jobName = jobName;
+        this.jobPriority = jobPriority != null ? jobPriority : JobPriority.MEDIUM;
+    }
+
+    public JobPriority getJobPriority() {
+        return jobPriority;
+    }
+
+    @Override
+    public void run() {
+        try {
+            System.out.println("Job:" + jobName + " Priority:" + jobPriority);
+            Thread.sleep(1000);
+        } catch (InterruptedException ignored) {
+        }
+    }
+}

core-java-concurrency/src/main/java/com/baeldung/concurrent/prioritytaskexecution/JobPriority.java

@@ -0,0 +1,7 @@
+package com.baeldung.concurrent.prioritytaskexecution;
+
+public enum JobPriority {
+    HIGH,
+    MEDIUM,
+    LOW
+}

core-java-concurrency/src/main/java/com/baeldung/concurrent/prioritytaskexecution/PriorityJobScheduler.java

@@ -0,0 +1,56 @@
+package com.baeldung.concurrent.prioritytaskexecution;
+
+import java.util.Comparator;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.PriorityBlockingQueue;
+import java.util.concurrent.TimeUnit;
+
+public class PriorityJobScheduler {
+
+    private ExecutorService priorityJobPoolExecutor;
+    private ExecutorService priorityJobScheduler;
+    private PriorityBlockingQueue<Runnable> 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);
+
+        priorityJobScheduler = Executors.newSingleThreadExecutor();
+        priorityJobScheduler.execute(()->{
+            while (true) {
+                try {
+                    priorityJobPoolExecutor.execute(priorityQueue.take());
+                } catch (InterruptedException e) {
+                    break;
+                }
+            }
+        });
+    }
+
+    public void scheduleJob(Job job) {
+        priorityQueue.add(job);
+    }
+
+    public int getQueuedTaskCount() {
+        return priorityQueue.size();
+    }
+
+    protected void close(ExecutorService scheduler) {
+        scheduler.shutdown();
+        try {
+            if (!scheduler.awaitTermination(5, TimeUnit.SECONDS)) {
+                scheduler.shutdownNow();
+            }
+        } catch (InterruptedException e) {
+            scheduler.shutdownNow();
+        }
+    }
+
+    public void closeScheduler() {
+        close(priorityJobPoolExecutor);
+        close(priorityJobScheduler);
+    }
+}

core-java-concurrency/src/main/java/com/baeldung/concurrent/waitandnotify/Data.java

@@ -11,7 +11,10 @@ public class Data {
         while (transfer) {
             try {
                 wait();
-            } catch (InterruptedException e) {}
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt(); 
+                System.out.println("Thread Interrupted");
+            }
         }
         transfer = true;
 
@@ -23,7 +26,10 @@ public class Data {
         while (!transfer) {
             try { 
                 wait();
-            } catch (InterruptedException e) {}
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt(); 
+                System.out.println("Thread Interrupted");
+            }
         }
         transfer = false;
         

core-java-concurrency/src/main/java/com/baeldung/concurrent/waitandnotify/Receiver.java

@@ -19,7 +19,10 @@ public class Receiver implements Runnable {
             //Thread.sleep() to mimic heavy server-side processing
             try {
                 Thread.sleep(ThreadLocalRandom.current().nextInt(1000, 5000));
-            } catch (InterruptedException e) {}
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt(); 
+                System.out.println("Thread Interrupted");
+            }
         }
     }
 }

core-java-concurrency/src/main/java/com/baeldung/concurrent/waitandnotify/Sender.java

@@ -11,11 +11,11 @@ public class Sender implements Runnable {
  
     public void run() {
         String packets[] = {
-            "First packet",
-            "Second packet",
-            "Third packet",
-            "Fourth packet",
-            "End"
+          "First packet",
+          "Second packet",
+          "Third packet",
+          "Fourth packet",
+          "End"
         };
  
         for (String packet : packets) {
@@ -24,7 +24,10 @@ public class Sender implements Runnable {
             //Thread.sleep() to mimic heavy server-side processing
             try {
                 Thread.sleep(ThreadLocalRandom.current().nextInt(1000, 5000));
-            } catch (InterruptedException e) {}
+            } catch (InterruptedException e) {
+                Thread.currentThread().interrupt(); 
+                System.out.println("Thread Interrupted");
+            }
         }
     }
 }

core-java-concurrency/src/test/java/com/baeldung/concurrent/prioritytaskexecution/PriorityJobSchedulerUnitTest.java

@@ -0,0 +1,38 @@
+package com.baeldung.concurrent.prioritytaskexecution;
+
+import org.junit.Test;
+
+public class PriorityJobSchedulerUnitTest {
+    private static int POOL_SIZE = 1;
+    private static int QUEUE_SIZE = 10;
+    
+    @Test
+    public void whenMultiplePriorityJobsQueued_thenHighestPriorityJobIsPicked() {
+        Job job1 = new Job("Job1", JobPriority.LOW);
+        Job job2 = new Job("Job2", JobPriority.MEDIUM);
+        Job job3 = new Job("Job3", JobPriority.HIGH);
+        Job job4 = new Job("Job4", JobPriority.MEDIUM);
+        Job job5 = new Job("Job5", JobPriority.LOW);
+        Job job6 = new Job("Job6", JobPriority.HIGH);
+        
+        PriorityJobScheduler pjs = new PriorityJobScheduler(POOL_SIZE, QUEUE_SIZE);
+        
+        pjs.scheduleJob(job1);
+        pjs.scheduleJob(job2);
+        pjs.scheduleJob(job3);
+        pjs.scheduleJob(job4);
+        pjs.scheduleJob(job5);
+        pjs.scheduleJob(job6);
+        
+        // ensure no tasks is pending before closing the scheduler
+        while (pjs.getQueuedTaskCount() != 0);
+        
+        // delay to avoid job sleep (added for demo) being interrupted
+        try {
+            Thread.sleep(2000);
+        } catch (InterruptedException ignored) {
+        }
+        
+        pjs.closeScheduler();
+    }
+}

core-java-concurrency/src/test/java/com/baeldung/concurrent/waitandnotify/NetworkIntegrationTest.java

@@ -13,38 +13,38 @@ import org.junit.Test;
 
 public class NetworkIntegrationTest {
 
-	private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
-	private final ByteArrayOutputStream errContent = new ByteArrayOutputStream();
-	private String expected;
-	
-	@Before
-	public void setUpStreams() {
-	    System.setOut(new PrintStream(outContent));
-	    System.setErr(new PrintStream(errContent));
-	}
-	
-	@Before
-	public void setUpExpectedOutput() {
-		StringWriter expectedStringWriter = new StringWriter();
-		
-		PrintWriter printWriter = new PrintWriter(expectedStringWriter);
-		printWriter.println("First packet");
-		printWriter.println("Second packet");
-		printWriter.println("Third packet");
-		printWriter.println("Fourth packet");
-		printWriter.close();
-		
-		expected = expectedStringWriter.toString();
-	}
+    private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+    private final ByteArrayOutputStream errContent = new ByteArrayOutputStream();
+    private String expected;
+    
+    @Before
+    public void setUpStreams() {
+        System.setOut(new PrintStream(outContent));
+        System.setErr(new PrintStream(errContent));
+    }
+    
+    @Before
+    public void setUpExpectedOutput() {
+        StringWriter expectedStringWriter = new StringWriter();
+        
+        PrintWriter printWriter = new PrintWriter(expectedStringWriter);
+        printWriter.println("First packet");
+        printWriter.println("Second packet");
+        printWriter.println("Third packet");
+        printWriter.println("Fourth packet");
+        printWriter.close();
+        
+        expected = expectedStringWriter.toString();
+    }
 
-	@After
-	public void cleanUpStreams() {
-	    System.setOut(null);
-	    System.setErr(null);
-	}
-	
-	@Test
-	public void givenSenderAndReceiver_whenSendingPackets_thenNetworkSynchronized() {
+    @After
+    public void cleanUpStreams() {
+        System.setOut(null);
+        System.setErr(null);
+    }
+    
+    @Test
+    public void givenSenderAndReceiver_whenSendingPackets_thenNetworkSynchronized() {
         Data data = new Data();
         Thread sender = new Thread(new Sender(data));
         Thread receiver = new Thread(new Receiver(data));
@@ -54,12 +54,13 @@ public class NetworkIntegrationTest {
         
         //wait for sender and receiver to finish before we test against expected
         try {
-			sender.join();
-			receiver.join();
-		} catch (InterruptedException e) {
-			e.printStackTrace();
-		}
-		
-	    assertEquals(expected, outContent.toString());
-	}
+            sender.join();
+            receiver.join();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt(); 
+            System.out.println("Thread Interrupted");
+        }
+        
+        assertEquals(expected, outContent.toString());
+    }
 }

core-java/README.md

@@ -126,3 +126,4 @@
 - [A Guide to Inner Interfaces in Java](http://www.baeldung.com/java-inner-interfaces)
 - [Polymorphism in Java](http://www.baeldung.com/java-polymorphism)
 - [Recursion In Java](http://www.baeldung.com/java-recursion)
+- [A Guide to the finalize Method in Java](http://www.baeldung.com/java-finalize)

core-java/src/main/java/com/baeldung/designpatterns/observer/Channel.java

@@ -0,0 +1,5 @@
+package com.baeldung.designpatterns.observer;
+
+public interface Channel {
+    public void update(Object o);
+}

core-java/src/main/java/com/baeldung/designpatterns/observer/NewsAgency.java

@@ -0,0 +1,24 @@
+package com.baeldung.designpatterns.observer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class NewsAgency {
+    private String news;
+    private List<Channel> channels = new ArrayList<>();
+
+    public void addObserver(Channel channel) {
+        this.channels.add(channel);
+    }
+
+    public void removeObserver(Channel channel) {
+        this.channels.remove(channel);
+    }
+
+    public void setNews(String news) {
+        this.news = news;
+        for (Channel channel : this.channels) {
+            channel.update(this.news);
+        }
+    }
+}

core-java/src/main/java/com/baeldung/designpatterns/observer/NewsChannel.java

@@ -0,0 +1,20 @@
+package com.baeldung.designpatterns.observer;
+
+public class NewsChannel implements Channel {
+
+    private String news;
+
+    @Override
+    public void update(Object news) {
+        this.setNews((String) news);
+    }
+
+    public String getNews() {
+        return news;
+    }
+
+    public void setNews(String news) {
+        this.news = news;
+    }
+
+}

core-java/src/main/java/com/baeldung/designpatterns/observer/ONewsAgency.java

@@ -0,0 +1,13 @@
+package com.baeldung.designpatterns.observer;
+
+import java.util.Observable;
+
+public class ONewsAgency extends Observable {
+    private String news;
+
+    public void setNews(String news) {
+        this.news = news;
+        setChanged();
+        notifyObservers(news);
+    }
+}

core-java/src/main/java/com/baeldung/designpatterns/observer/ONewsChannel.java

@@ -0,0 +1,22 @@
+package com.baeldung.designpatterns.observer;
+
+import java.util.Observable;
+import java.util.Observer;
+
+public class ONewsChannel implements Observer {
+
+    private String news;
+
+    @Override
+    public void update(Observable o, Object news) {
+        this.setNews((String) news);
+    }
+
+    public String getNews() {
+        return news;
+    }
+
+    public void setNews(String news) {
+        this.news = news;
+    }
+}

core-java/src/main/java/com/baeldung/designpatterns/observer/PCLNewsAgency.java

@@ -0,0 +1,28 @@
+package com.baeldung.designpatterns.observer;
+
+import java.beans.PropertyChangeListener;
+import java.beans.PropertyChangeSupport;
+
+public class PCLNewsAgency {
+    private String news;
+
+    private PropertyChangeSupport support;
+
+    public PCLNewsAgency() {
+        support = new PropertyChangeSupport(this);
+    }
+
+    public void addPropertyChangeListener(PropertyChangeListener pcl) {
+        support.addPropertyChangeListener(pcl);
+    }
+
+    public void removePropertyChangeListener(PropertyChangeListener pcl) {
+        support.removePropertyChangeListener(pcl);
+    }
+
+    public void setNews(String value) {
+        support.firePropertyChange("news", this.news, value);
+        this.news = value;
+
+    }
+}

core-java/src/main/java/com/baeldung/designpatterns/observer/PCLNewsChannel.java

@@ -0,0 +1,21 @@
+package com.baeldung.designpatterns.observer;
+
+import java.beans.PropertyChangeEvent;
+import java.beans.PropertyChangeListener;
+
+public class PCLNewsChannel implements PropertyChangeListener {
+
+    private String news;
+
+    public void propertyChange(PropertyChangeEvent evt) {
+        this.setNews((String) evt.getNewValue());
+    }
+
+    public String getNews() {
+        return news;
+    }
+
+    public void setNews(String news) {
+        this.news = news;
+    }
+}

core-java/src/main/java/com/baeldung/finalize/CloseableResource.java

@@ -0,0 +1,30 @@
+package com.baeldung.finalize;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+public class CloseableResource implements AutoCloseable {
+    private BufferedReader reader;
+
+    public CloseableResource() {
+        InputStream input = this.getClass().getClassLoader().getResourceAsStream("file.txt");
+        reader = new BufferedReader(new InputStreamReader(input));
+    }
+
+    public String readFirstLine() throws IOException {
+        String firstLine = reader.readLine();
+        return firstLine;
+    }
+
+    @Override
+    public void close() {
+        try {
+            reader.close();
+            System.out.println("Closed BufferedReader in the close method");
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}

core-java/src/main/java/com/baeldung/finalize/Finalizable.java

@@ -0,0 +1,30 @@
+package com.baeldung.finalize;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+
+public class Finalizable {
+    private BufferedReader reader;
+
+    public Finalizable() {
+        InputStream input = this.getClass().getClassLoader().getResourceAsStream("file.txt");
+        reader = new BufferedReader(new InputStreamReader(input));
+    }
+
+    public String readFirstLine() throws IOException {
+        String firstLine = reader.readLine();
+        return firstLine;
+    }
+
+    @Override
+    public void finalize() {
+        try {
+            reader.close();
+            System.out.println("Closed BufferedReader in the finalizer");
+        } catch (IOException e) {
+            e.printStackTrace();
+        }
+    }
+}

core-java/src/main/java/com/baeldung/javac/Data.java

@@ -0,0 +1,16 @@
+package com.baeldung.javac;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Data {
+    List<String> textList = new ArrayList();
+
+    public void addText(String text) {
+        textList.add(text);
+    }
+
+    public List getTextList() {
+        return this.textList;
+    }
+}

core-java/src/main/java/com/baeldung/trie/Trie.java

@@ -0,0 +1,62 @@
+package com.baeldung.trie;
+
+public class Trie {
+    private TrieNode root;
+
+    Trie() {
+        root = new TrieNode();
+    }
+
+    public void insert(String word) {
+        TrieNode current = root;
+
+        for (int i = 0; i < word.length(); i++) {
+            current = current.getChildren().computeIfAbsent(word.charAt(i), c -> new TrieNode());
+        }
+        current.setEndOfWord(true);
+    }
+
+    public boolean delete(String word) {
+        return delete(root, word, 0);
+    }
+
+    public boolean containsNode(String word) {
+        TrieNode current = root;
+
+        for (int i = 0; i < word.length(); i++) {
+            char ch = word.charAt(i);
+            TrieNode node = current.getChildren().get(ch);
+            if (node == null) {
+                return false;
+            }
+            current = node;
+        }
+        return current.isEndOfWord();
+    }
+
+    public boolean isEmpty() {
+        return root == null;
+    }
+
+    private boolean delete(TrieNode current, String word, int index) {
+        if (index == word.length()) {
+            if (!current.isEndOfWord()) {
+                return false;
+            }
+            current.setEndOfWord(false);
+            return current.getChildren().isEmpty();
+        }
+        char ch = word.charAt(index);
+        TrieNode node = current.getChildren().get(ch);
+        if (node == null) {
+            return false;
+        }
+        boolean shouldDeleteCurrentNode = delete(node, word, index + 1);
+
+        if (shouldDeleteCurrentNode) {
+            current.getChildren().remove(ch);
+            return current.getChildren().isEmpty();
+        }
+        return false;
+    }
+}

core-java/src/main/java/com/baeldung/trie/TrieNode.java

@@ -0,0 +1,31 @@
+package com.baeldung.trie;
+
+import java.util.HashMap;
+import java.util.Map;
+
+class TrieNode {
+    private Map<Character, TrieNode> children;
+    private boolean endOfWord;
+
+    public TrieNode() {
+        children = new HashMap<>();
+        endOfWord = false;
+    }
+
+    public Map<Character, TrieNode> getChildren() {
+        return children;
+    }
+
+    public void setChildren(Map<Character, TrieNode> children) {
+        this.children = children;
+    }
+
+    public boolean isEndOfWord() {
+        return endOfWord;
+    }
+
+    public void setEndOfWord(boolean endOfWord) {
+        this.endOfWord = endOfWord;
+    }
+
+}

core-java/src/main/java/javac-args/arguments

@@ -0,0 +1,2 @@
+-d javac-target -verbose
+com/baeldung/javac/Data.java

core-java/src/main/java/javac-args/options

@@ -0,0 +1,2 @@
+-d javac-target
+-verbose

core-java/src/main/java/javac-args/types

@@ -0,0 +1 @@
+com/baeldung/javac/Data.java

core-java/src/main/java/javac-args/xlint-ops

@@ -0,0 +1,3 @@
+-d javac-target
+-Xlint:rawtypes,unchecked,static,cast,serial,fallthrough
+com/baeldung/javac/Data.java

core-java/src/test/java/com/baeldung/designpatterns/observer/ObserverIntegrationTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.designpatterns.observer;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import com.baeldung.designpatterns.observer.NewsAgency;
+import com.baeldung.designpatterns.observer.NewsChannel;
+
+public class ObserverIntegrationTest {
+
+    @Test
+    public void whenChangingNewsAgencyState_thenNewsChannelNotified() {
+
+        NewsAgency observable = new NewsAgency();
+        NewsChannel observer = new NewsChannel();
+
+        observable.addObserver(observer);
+
+        observable.setNews("news");
+        assertEquals(observer.getNews(), "news");
+    }
+
+    @Test
+    public void whenChangingONewsAgencyState_thenONewsChannelNotified() {
+
+        ONewsAgency observable = new ONewsAgency();
+        ONewsChannel observer = new ONewsChannel();
+
+        observable.addObserver(observer);
+
+        observable.setNews("news");
+        assertEquals(observer.getNews(), "news");
+    }
+
+    @Test
+    public void whenChangingPCLNewsAgencyState_thenONewsChannelNotified() {
+
+        PCLNewsAgency observable = new PCLNewsAgency();
+        PCLNewsChannel observer = new PCLNewsChannel();
+
+        observable.addPropertyChangeListener(observer);
+
+        observable.setNews("news");
+        assertEquals(observer.getNews(), "news");
+    }
+}

core-java/src/test/java/com/baeldung/finalize/FinalizeUnitTest.java

@@ -0,0 +1,23 @@
+package com.baeldung.finalize;
+
+import java.io.IOException;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+public class FinalizeUnitTest {
+    @Test
+    public void whenGC_thenFinalizerExecuted() throws IOException {
+        String firstLine = new Finalizable().readFirstLine();
+        Assert.assertEquals("baeldung.com", firstLine);
+        System.gc();
+    }
+
+    @Test
+    public void whenTryWResourcesExits_thenResourceClosed() throws IOException {
+        try (CloseableResource resource = new CloseableResource()) {
+            String firstLine = resource.readFirstLine();
+            Assert.assertEquals("baeldung.com", firstLine);
+        }
+    }
+}

core-java/src/test/java/com/baeldung/trie/TrieTest.java

@@ -0,0 +1,68 @@
+package com.baeldung.trie;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class TrieTest {
+
+    @Test
+    public void whenEmptyTrie_thenNoElements() {
+        Trie trie = new Trie();
+
+        assertFalse(trie.isEmpty());
+    }
+
+    @Test
+    public void givenATrie_whenAddingElements_thenTrieNotEmpty() {
+        Trie trie = createExampleTrie();
+
+        assertFalse(trie.isEmpty());
+    }
+
+    @Test
+    public void givenATrie_whenAddingElements_thenTrieHasThoseElements() {
+        Trie trie = createExampleTrie();
+
+        assertFalse(trie.containsNode("3"));
+        assertFalse(trie.containsNode("vida"));
+
+        assertTrue(trie.containsNode("Programming"));
+        assertTrue(trie.containsNode("is"));
+        assertTrue(trie.containsNode("a"));
+        assertTrue(trie.containsNode("way"));
+        assertTrue(trie.containsNode("of"));
+        assertTrue(trie.containsNode("life"));
+    }
+
+    @Test
+    public void givenATrie_whenLookingForNonExistingElement_thenReturnsFalse() {
+        Trie trie = createExampleTrie();
+
+        assertFalse(trie.containsNode("99"));
+    }
+
+    @Test
+    public void givenATrie_whenDeletingElements_thenTreeDoesNotContainThoseElements() {
+
+        Trie trie = createExampleTrie();
+
+        assertTrue(trie.containsNode("Programming"));
+        trie.delete("Programming");
+        assertFalse(trie.containsNode("Programming"));
+    }
+
+    private Trie createExampleTrie() {
+        Trie trie = new Trie();
+
+        trie.insert("Programming");
+        trie.insert("is");
+        trie.insert("a");
+        trie.insert("way");
+        trie.insert("of");
+        trie.insert("life");
+
+        return trie;
+    }
+}

core-kotlin/pom.xml

@@ -49,6 +49,11 @@
             <artifactId>kotlin-stdlib-jre8</artifactId>
             <version>${kotlin-stdlib.version}</version>
         </dependency>
+        <dependency>
+            <groupId>khttp</groupId>
+            <artifactId>khttp</artifactId>
+            <version>0.1.0</version>
+        </dependency>
         <dependency>
             <groupId>org.jetbrains.kotlin</groupId>
             <artifactId>kotlin-test-junit</artifactId>

core-kotlin/src/test/kotlin/com/baeldung/kotlin/khttp/KhttpTest.kt

@@ -0,0 +1,153 @@
+package com.baeldung.kotlin.khttp
+
+import khttp.structures.files.FileLike
+import org.json.JSONObject
+import org.junit.Test
+import java.beans.ExceptionListener
+import java.beans.XMLEncoder
+import java.io.*
+import java.lang.Exception
+import java.net.ConnectException
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+import kotlin.test.fail
+
+class KhttpTest {
+
+    @Test
+    fun whenHttpGetRequestIsMade_thenArgsAreReturned() {
+        val response = khttp.get(
+                url = "http://httpbin.org/get",
+                params = mapOf("p1" to "1", "p2" to "2"))
+        val args = response.jsonObject.getJSONObject("args")
+
+        assertEquals("1", args["p1"])
+        assertEquals("2", args["p2"])
+    }
+
+    @Test
+    fun whenAlternateHttpGetRequestIsMade_thenArgsAreReturned() {
+        val response = khttp.request(
+                method = "GET",
+                url = "http://httpbin.org/get",
+                params = mapOf("p1" to "1", "p2" to "2"))
+        val args = response.jsonObject.getJSONObject("args")
+
+        assertEquals("1", args["p1"])
+        assertEquals("2", args["p2"])
+    }
+
+    @Test
+    fun whenHeadersAreSet_thenHeadersAreSent() {
+        val response = khttp.get(
+                url = "http://httpbin.org/get",
+                headers = mapOf("header1" to "1", "header2" to "2"))
+        val headers = response.jsonObject.getJSONObject("headers")
+
+        assertEquals("1", headers["Header1"])
+        assertEquals("2", headers["Header2"])
+    }
+
+    @Test
+    fun whenHttpPostRequestIsMadeWithJson_thenBodyIsReturned() {
+        val response = khttp.post(
+                url = "http://httpbin.org/post",
+                params = mapOf("p1" to "1", "p2" to "2"),
+                json = mapOf("pr1" to "1", "pr2" to "2"))
+
+        val args = response.jsonObject.getJSONObject("args")
+
+        assertEquals("1", args["p1"])
+        assertEquals("2", args["p2"])
+
+        val json = response.jsonObject.getJSONObject("json")
+
+        assertEquals("1", json["pr1"])
+        assertEquals("2", json["pr2"])
+    }
+
+    @Test
+    fun whenHttpPostRequestIsMadeWithMapData_thenBodyIsReturned() {
+        val response = khttp.post(
+                url = "http://httpbin.org/post",
+                params = mapOf("p1" to "1", "p2" to "2"),
+                data = mapOf("pr1" to "1", "pr2" to "2"))
+
+        val args = response.jsonObject.getJSONObject("args")
+
+        assertEquals("1", args["p1"])
+        assertEquals("2", args["p2"])
+
+        val form = response.jsonObject.getJSONObject("form")
+
+        assertEquals("1", form["pr1"])
+        assertEquals("2", form["pr2"])
+    }
+
+    @Test
+    fun whenHttpPostRequestIsMadeWithFiles_thenBodyIsReturned() {
+        val response = khttp.post(
+                url = "http://httpbin.org/post",
+                params = mapOf("p1" to "1", "p2" to "2"),
+                files = listOf(
+                        FileLike("file1", "content1"),
+                        FileLike("file2", javaClass.getResource("KhttpTest.class").openStream().readBytes())))
+
+        val args = response.jsonObject.getJSONObject("args")
+
+        assertEquals("1", args["p1"])
+        assertEquals("2", args["p2"])
+
+        val files = response.jsonObject.getJSONObject("files")
+
+        assertEquals("content1", files["file1"])
+    }
+
+    @Test
+    fun whenHttpPostRequestIsMadeWithInputStream_thenBodyIsReturned() {
+        val response = khttp.post(
+                url = "http://httpbin.org/post",
+                params = mapOf("p1" to "1", "p2" to "2"),
+                data = ByteArrayInputStream("content!".toByteArray()))
+
+        val args = response.jsonObject.getJSONObject("args")
+
+        assertEquals("1", args["p1"])
+        assertEquals("2", args["p2"])
+
+        assertEquals("content!", response.jsonObject["data"])
+    }
+
+    @Test
+    fun whenHttpPostStreamingRequestIsMade_thenBodyIsReturnedInChunks() {
+        val response = khttp.post(
+                url = "http://httpbin.org/post",
+                stream = true,
+                json = mapOf("pr1" to "1", "pr2" to "2"))
+
+        val baos = ByteArrayOutputStream()
+        response.contentIterator(chunkSize = 10).forEach { arr : ByteArray -> baos.write(arr) }
+        val json = JSONObject(String(baos.toByteArray())).getJSONObject("json")
+
+        assertEquals("1", json["pr1"])
+        assertEquals("2", json["pr2"])
+    }
+
+    @Test
+    fun whenHttpRequestFails_thenExceptionIsThrown() {
+        try {
+            khttp.get(url = "http://localhost/nothing/to/see/here")
+
+            fail("Should have thrown an exception")
+        } catch (e : ConnectException) {
+            //Ok
+        }
+    }
+
+    @Test
+    fun whenHttpNotFound_thenExceptionIsThrown() {
+        val response = khttp.get(url = "http://httpbin.org/nothing/to/see/here")
+
+        assertEquals(404, response.statusCode)
+    }
+}

guava/src/main/java/org/baeldung/guava/memoizer/CostlySupplier.java

@@ -0,0 +1,17 @@
+package org.baeldung.guava.memoizer;
+
+import java.math.BigInteger;
+import java.util.Random;
+import java.util.concurrent.TimeUnit;
+
+public class CostlySupplier {
+
+    public static BigInteger generateBigNumber() {
+        try {
+            TimeUnit.SECONDS.sleep(2);
+        } catch (InterruptedException e) {
+        }
+        return new BigInteger("12345");
+    }
+
+}

guava/src/main/java/org/baeldung/guava/memoizer/Factorial.java

@@ -0,0 +1,22 @@
+package org.baeldung.guava.memoizer;
+
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+
+import java.math.BigInteger;
+
+public class Factorial {
+
+    private static LoadingCache<Integer, BigInteger> memo = CacheBuilder.newBuilder()
+            .build(CacheLoader.from(Factorial::getFactorial));
+
+    public static BigInteger getFactorial(int n) {
+        if (n == 0) {
+            return BigInteger.ONE;
+        } else {
+            return BigInteger.valueOf(n).multiply(memo.getUnchecked(n - 1));
+        }
+    }
+
+}

guava/src/main/java/org/baeldung/guava/memoizer/FibonacciSequence.java

@@ -0,0 +1,26 @@
+package org.baeldung.guava.memoizer;
+
+import com.google.common.cache.CacheBuilder;
+import com.google.common.cache.CacheLoader;
+import com.google.common.cache.LoadingCache;
+
+import java.math.BigInteger;
+import java.util.concurrent.TimeUnit;
+
+public class FibonacciSequence {
+
+    private static LoadingCache<Integer, BigInteger> memo = CacheBuilder.newBuilder()
+            .maximumSize(100)
+            .build(CacheLoader.from(FibonacciSequence::getFibonacciNumber));
+
+    public static BigInteger getFibonacciNumber(int n) {
+        if (n == 0) {
+            return BigInteger.ZERO;
+        } else if (n == 1) {
+            return BigInteger.ONE;
+        } else {
+            return memo.getUnchecked(n - 1).add(memo.getUnchecked(n - 2));
+        }
+    }
+
+}

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

@@ -0,0 +1,92 @@
+package org.baeldung.guava;
+
+import com.google.common.base.Suppliers;
+import org.baeldung.guava.memoizer.CostlySupplier;
+import org.baeldung.guava.memoizer.Factorial;
+import org.baeldung.guava.memoizer.FibonacciSequence;
+import org.junit.Test;
+
+import java.math.BigInteger;
+import java.time.Duration;
+import java.time.Instant;
+import java.util.concurrent.TimeUnit;
+import java.util.function.Supplier;
+
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsEqual.equalTo;
+import static org.hamcrest.number.IsCloseTo.closeTo;
+import static org.junit.Assert.assertThat;
+
+public class GuavaMemoizerUnitTest {
+
+    @Test
+    public void givenInteger_whenGetFibonacciNumber_thenShouldCalculateFibonacciNumber() {
+        // given
+        int n = 95;
+
+        // when
+        BigInteger fibonacciNumber = FibonacciSequence.getFibonacciNumber(n);
+
+        // then
+        BigInteger expectedFibonacciNumber = new BigInteger("31940434634990099905");
+        assertThat(fibonacciNumber, is(equalTo(expectedFibonacciNumber)));
+    }
+
+    @Test
+    public void givenInteger_whenGetFactorial_thenShouldCalculateFactorial() {
+        // given
+        int n = 95;
+
+        // when
+        BigInteger factorial = Factorial.getFactorial(n);
+
+        // then
+        BigInteger expectedFactorial = new BigInteger("10329978488239059262599702099394727095397746340117372869212250571234293987594703124871765375385424468563282236864226607350415360000000000000000000000");
+        assertThat(factorial, is(equalTo(expectedFactorial)));
+    }
+
+    @Test
+    public void givenMemoizedSupplier_whenGet_thenSubsequentGetsAreFast() {
+        // given
+        Supplier<BigInteger> memoizedSupplier;
+        memoizedSupplier = Suppliers.memoize(CostlySupplier::generateBigNumber);
+
+        // when
+        BigInteger expectedValue = new BigInteger("12345");
+        assertSupplierGetExecutionResultAndDuration(memoizedSupplier, expectedValue, 2000D);
+
+        // then
+        assertSupplierGetExecutionResultAndDuration(memoizedSupplier, expectedValue, 0D);
+        assertSupplierGetExecutionResultAndDuration(memoizedSupplier, expectedValue, 0D);
+    }
+
+    @Test
+    public void givenMemoizedSupplierWithExpiration_whenGet_thenSubsequentGetsBeforeExpiredAreFast() throws InterruptedException {
+        // given
+        Supplier<BigInteger> memoizedSupplier;
+        memoizedSupplier = Suppliers.memoizeWithExpiration(CostlySupplier::generateBigNumber, 3, TimeUnit.SECONDS);
+
+        // when
+        BigInteger expectedValue = new BigInteger("12345");
+        assertSupplierGetExecutionResultAndDuration(memoizedSupplier, expectedValue, 2000D);
+
+        // then
+        assertSupplierGetExecutionResultAndDuration(memoizedSupplier, expectedValue, 0D);
+        // add one more second until memoized Supplier is evicted from memory
+        TimeUnit.SECONDS.sleep(1);
+        assertSupplierGetExecutionResultAndDuration(memoizedSupplier, expectedValue, 2000D);
+    }
+
+    private <T> void assertSupplierGetExecutionResultAndDuration(Supplier<T> supplier,
+                                                                 T expectedValue,
+                                                                 double expectedDurationInMs) {
+        Instant start = Instant.now();
+        T value = supplier.get();
+        Long durationInMs = Duration.between(start, Instant.now()).toMillis();
+        double marginOfErrorInMs = 100D;
+
+        assertThat(value, is(equalTo(expectedValue)));
+        assertThat(durationInMs.doubleValue(), is(closeTo(expectedDurationInMs, marginOfErrorInMs)));
+    }
+
+}

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()

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;
+    }
+
+}

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 {

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;
+    }
+
+}

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;
+    }
+
+}

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);
+    }
+
+}

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.

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());
 

java-rmi/pom.xml

@@ -0,0 +1,20 @@
+<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.rmi</groupId>
+  <artifactId>java-rmi</artifactId>
+  <version>1.0-SNAPSHOT</version>
+  <packaging>jar</packaging>
+  
+  <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-modules</artifactId>
+        <version>1.0.0-SNAPSHOT</version>
+  </parent>
+  
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+  
+</project>

java-rmi/src/main/java/com/baeldung/rmi/Message.java

@@ -0,0 +1,36 @@
+package com.baeldung.rmi;
+
+import java.io.Serializable;
+
+public class Message implements Serializable {
+	
+	private String messageText;
+	
+	private String contentType;
+	
+	public Message() {
+	}
+	
+	public Message(String messageText, String contentType) {
+		
+		this.messageText = messageText;
+		this.contentType = contentType;
+	}
+	
+	public String getMessageText() {
+		return messageText;
+	}
+
+	public void setMessageText(String messageText) {
+		this.messageText = messageText;
+	}
+
+	public String getContentType() {
+		return contentType;
+	}
+
+	public void setContentType(String contentType) {
+		this.contentType = contentType;
+	}
+	
+}

java-rmi/src/main/java/com/baeldung/rmi/MessengerService.java

@@ -0,0 +1,11 @@
+package com.baeldung.rmi;
+
+import java.rmi.Remote;
+import java.rmi.RemoteException;
+
+public interface MessengerService extends Remote {
+
+	public String sendMessage(String clientMessage) throws RemoteException;
+
+	public Message sendMessage(Message clientMessage) throws RemoteException;
+}

java-rmi/src/main/java/com/baeldung/rmi/MessengerServiceImpl.java

@@ -0,0 +1,37 @@
+package com.baeldung.rmi;
+
+import java.rmi.RemoteException;
+import java.rmi.registry.LocateRegistry;
+import java.rmi.registry.Registry;
+import java.rmi.server.UnicastRemoteObject;
+
+public class MessengerServiceImpl implements MessengerService {
+
+	public String sendMessage(String clientMessage) {
+		
+		String serverMessage = null;
+		if (clientMessage.equals("Client Message")) {
+			serverMessage = "Server Message";
+		}
+		
+		return serverMessage;
+	}
+	
+	public void createStubAndBind() throws RemoteException {
+		
+		MessengerService stub = (MessengerService) UnicastRemoteObject.exportObject((MessengerService) this, 0);
+		Registry registry = LocateRegistry.createRegistry(1099);
+		registry.rebind("MessengerService", stub);
+	}
+	
+	public Message sendMessage(Message clientMessage) throws RemoteException {
+		
+		Message serverMessage = null;
+		if (clientMessage.getMessageText().equals("Client Message")) {
+			serverMessage = new Message("Server Message", "text/plain");
+		}
+		
+		return serverMessage;
+	}
+	
+}

java-rmi/src/test/java/com/baeldung/rmi/JavaRMIIntegrationTest.java

@@ -0,0 +1,44 @@
+package com.baeldung.rmi;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.rmi.NotBoundException;
+import java.rmi.RemoteException;
+import java.rmi.registry.LocateRegistry;
+import java.rmi.registry.Registry;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+public class JavaRMIIntegrationTest {
+	
+	@BeforeClass
+	public static void whenRunServer_thenServerStarts() {
+		
+		try {
+			MessengerServiceImpl server = new MessengerServiceImpl();
+			server.createStubAndBind();
+		} catch (RemoteException e) {
+			fail("Exception Occurred");
+		}
+	}
+	
+	@Test
+	public void whenClientSendsMessageToServer_thenServerSendsResponseMessage() {
+		
+		try {
+			Registry registry = LocateRegistry.getRegistry();	
+			MessengerService server = (MessengerService) registry.lookup("MessengerService");			
+			String responseMessage = server.sendMessage("Client Message");		
+			
+			String expectedMessage = "Server Message";			
+			assertEquals(responseMessage, expectedMessage);
+		} catch (RemoteException e) {
+			fail("Exception Occurred");
+		} catch (NotBoundException nb) {
+			fail("Exception Occurred");
+		}
+	}
+	
+}

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
+
+```

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>

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();
+    }
+
+}
+
+

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>

json/pom.xml

@@ -31,6 +31,11 @@
             <version>${fastjson.version}</version>
         </dependency>
 
+        <dependency>
+            <groupId>org.json</groupId>
+            <artifactId>json</artifactId>
+            <version>20171018</version>
+        </dependency>
     </dependencies>
 
     <properties>

json/src/main/java/com/baeldung/jsonjava/CDLDemo.java

@@ -0,0 +1,59 @@
+package com.baeldung.jsonjava;
+
+import org.json.CDL;
+import org.json.JSONArray;
+import org.json.JSONTokener;
+
+public class CDLDemo {
+    public static void main(String[] args) {
+        System.out.println("7.1. Producing JSONArray Directly from Comma Delimited Text: ");
+        jsonArrayFromCDT();
+        
+        System.out.println("\n7.2. Producing Comma Delimited Text from JSONArray: ");
+        cDTfromJSONArray();
+        
+        System.out.println("\n7.3.1. Producing JSONArray of JSONObjects Using Comma Delimited Text: ");
+        jaOfJOFromCDT2();
+        
+        System.out.println("\n7.3.2. Producing JSONArray of JSONObjects Using Comma Delimited Text: ");
+        jaOfJOFromCDT2();
+    }
+    
+    public static void jsonArrayFromCDT() {
+        JSONArray ja = CDL.rowToJSONArray(new JSONTokener("England, USA, Canada"));
+        System.out.println(ja);
+    }
+    
+    public static void cDTfromJSONArray() {
+        JSONArray ja = new JSONArray("[\"England\",\"USA\",\"Canada\"]");
+        String cdt = CDL.rowToString(ja);
+        System.out.println(cdt);
+    }
+    
+    public static void jaOfJOFromCDT() {
+        String string = 
+          "name, city, age \n" +
+          "john, chicago, 22 \n" +
+          "gary, florida, 35 \n" +
+          "sal, vegas, 18";
+         
+        JSONArray result = CDL.toJSONArray(string);
+        System.out.println(result.toString());
+    }
+    
+    public static void jaOfJOFromCDT2() {
+        JSONArray ja = new JSONArray();
+        ja.put("name");
+        ja.put("city");
+        ja.put("age");
+         
+        String string = 
+          "john, chicago, 22 \n" +
+          "gary, florida, 35 \n" +
+          "sal, vegas, 18";
+         
+        JSONArray result = CDL.toJSONArray(ja, string);
+        System.out.println(result.toString());
+    }
+    
+}

json/src/main/java/com/baeldung/jsonjava/CookieDemo.java

@@ -0,0 +1,30 @@
+package com.baeldung.jsonjava;
+
+import org.json.Cookie;
+import org.json.JSONObject;
+
+public class CookieDemo {
+    public static void main(String[] args) {
+        System.out.println("8.1. Converting a Cookie String into a JSONObject");
+        cookieStringToJSONObject();
+        
+        System.out.println("\n8.2. Converting a JSONObject into Cookie String");
+        jSONObjectToCookieString();
+    }
+    
+    public static void cookieStringToJSONObject() {
+        String cookie = "username=John Doe; expires=Thu, 18 Dec 2013 12:00:00 UTC; path=/";
+        JSONObject cookieJO = Cookie.toJSONObject(cookie);
+        System.out.println(cookieJO);
+    }
+    
+    public static void jSONObjectToCookieString() {
+        JSONObject cookieJO = new JSONObject();
+        cookieJO.put("name", "username");
+        cookieJO.put("value", "John Doe");
+        cookieJO.put("expires", "Thu, 18 Dec 2013 12:00:00 UTC");
+        cookieJO.put("path", "/");
+        String cookie = Cookie.toString(cookieJO);
+        System.out.println(cookie);
+    }
+}

json/src/main/java/com/baeldung/jsonjava/DemoBean.java

@@ -0,0 +1,26 @@
+package com.baeldung.jsonjava;
+
+public class DemoBean {
+    private int id;
+    private String name;
+    private boolean active;
+    
+    public int getId() {
+        return id;
+    }
+    public void setId(int id) {
+        this.id = id;
+    }
+    public String getName() {
+        return name;
+    }
+    public void setName(String name) {
+        this.name = name;
+    }
+    public boolean isActive() {
+        return active;
+    }
+    public void setActive(boolean active) {
+        this.active = active;
+    }
+}

json/src/main/java/com/baeldung/jsonjava/HTTPDemo.java

@@ -0,0 +1,27 @@
+package com.baeldung.jsonjava;
+
+import org.json.HTTP;
+import org.json.JSONObject;
+
+public class HTTPDemo {
+    public static void main(String[] args) {
+        System.out.println("9.1. Converting JSONObject to HTTP Header: ");
+        jSONObjectToHTTPHeader();
+        
+        System.out.println("\n9.2. Converting HTTP Header String Back to JSONObject: ");
+        hTTPHeaderToJSONObject();
+    }
+    
+    public static void jSONObjectToHTTPHeader() {
+        JSONObject jo = new JSONObject();
+        jo.put("Method", "POST");
+        jo.put("Request-URI", "http://www.example.com/");
+        jo.put("HTTP-Version", "HTTP/1.1");
+        System.out.println(HTTP.toString(jo));
+    }
+    
+    public static void hTTPHeaderToJSONObject() {
+        JSONObject obj = HTTP.toJSONObject("POST \"http://www.example.com/\" HTTP/1.1");
+        System.out.println(obj);
+    }
+}

json/src/main/java/com/baeldung/jsonjava/JSONArrayDemo.java

@@ -0,0 +1,52 @@
+package com.baeldung.jsonjava;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.json.JSONArray;
+import org.json.JSONObject;
+
+public class JSONArrayDemo {
+    public static void main(String[] args) {
+        System.out.println("5.1. Creating JSON Array: ");
+        creatingJSONArray();
+        
+        System.out.println("\n5.2. Creating JSON Array from JSON string: ");
+        jsonArrayFromJSONString();
+        
+        System.out.println("\n5.3. Creating JSON Array from Collection Object: ");
+        jsonArrayFromCollectionObj();
+    }
+    
+    public static void creatingJSONArray() {
+        JSONArray ja = new JSONArray();
+        ja.put(Boolean.TRUE);
+        ja.put("lorem ipsum");
+         
+        // We can also put a JSONObject in JSONArray
+        JSONObject jo = new JSONObject();
+        jo.put("name", "jon doe");
+        jo.put("age", "22");
+        jo.put("city", "chicago");
+         
+        ja.put(jo);
+         
+        System.out.println(ja.toString());
+    }
+    
+    public static void jsonArrayFromJSONString() {
+        JSONArray ja = new JSONArray("[true, \"lorem ipsum\", 215]");
+        System.out.println(ja);
+    }
+    
+    public static void jsonArrayFromCollectionObj() {
+        List<String> list = new ArrayList<>();
+        list.add("California");
+        list.add("Texas");
+        list.add("Hawaii");
+        list.add("Alaska");
+         
+        JSONArray ja = new JSONArray(list);
+        System.out.println(ja);
+    }
+}

json/src/main/java/com/baeldung/jsonjava/JSONObjectDemo.java

@@ -0,0 +1,59 @@
+package com.baeldung.jsonjava;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.json.JSONObject;
+
+public class JSONObjectDemo {
+    public static void main(String[] args) {
+        System.out.println("4.1. Creating JSONObject: ");
+        jsonFromJSONObject();
+        
+        System.out.println("\n4.2. Creating JSONObject from Map: ");
+        jsonFromMap();
+        
+        System.out.println("\n4.3. Creating JSONObject from JSON string: ");
+        jsonFromJSONString();
+        
+        System.out.println("\n4.4. Creating JSONObject from Java Bean: ");
+        jsonFromDemoBean();
+    }
+    
+    public static void jsonFromJSONObject() {
+        JSONObject jo = new JSONObject();
+        jo.put("name", "jon doe");
+        jo.put("age", "22");
+        jo.put("city", "chicago");
+             
+        System.out.println(jo.toString());
+    }
+    
+    public static void jsonFromMap() {
+        Map<String, String> map = new HashMap<>();
+        map.put("name", "jon doe");
+        map.put("age", "22");
+        map.put("city", "chicago");
+        JSONObject jo = new JSONObject(map);
+         
+        System.out.println(jo.toString());
+    }
+    
+    public static void jsonFromJSONString() {
+        JSONObject jo = new JSONObject(
+          "{\"city\":\"chicago\",\"name\":\"jon doe\",\"age\":\"22\"}"
+        );
+        
+        System.out.println(jo.toString());
+    }
+    
+    public static void jsonFromDemoBean() {
+        DemoBean demo = new DemoBean();
+        demo.setId(1);
+        demo.setName("lorem ipsum");
+        demo.setActive(true);
+         
+        JSONObject jo = new JSONObject(demo);
+        System.out.println(jo);
+    }
+}

json/src/main/java/com/baeldung/jsonjava/JSONTokenerDemo.java

@@ -0,0 +1,13 @@
+package com.baeldung.jsonjava;
+
+import org.json.JSONTokener;
+
+public class JSONTokenerDemo {
+    public static void main(String[] args) {
+        JSONTokener jt = new JSONTokener("Sample String");
+         
+        while(jt.more()) {
+            System.out.println(jt.next());
+        }
+    }
+}

json/src/test/java/com/baeldung/jsonjava/CDLIntegrationTest.java

@@ -0,0 +1,52 @@
+package com.baeldung.jsonjava;
+
+import static org.junit.Assert.assertEquals;
+
+import org.json.CDL;
+import org.json.JSONArray;
+import org.json.JSONTokener;
+import org.junit.Test;
+
+public class CDLIntegrationTest {
+    @Test
+    public void givenCommaDelimitedText_thenConvertToJSONArray() {
+        JSONArray ja = CDL.rowToJSONArray(new JSONTokener("England, USA, Canada"));
+        assertEquals("[\"England\",\"USA\",\"Canada\"]", ja.toString());
+    }
+
+    @Test
+    public void givenJSONArray_thenConvertToCommaDelimitedText() {
+        JSONArray ja = new JSONArray("[\"England\",\"USA\",\"Canada\"]");
+        String cdt = CDL.rowToString(ja);
+        assertEquals("England,USA,Canada", cdt.toString().trim());
+    }
+
+    @Test
+    public void givenCommaDelimitedText_thenGetJSONArrayOfJSONObjects() {
+        String string = 
+          "name, city, age \n" +
+          "john, chicago, 22 \n" +
+          "gary, florida, 35 \n" +
+          "sal, vegas, 18";
+         
+        JSONArray result = CDL.toJSONArray(string);
+        assertEquals("[{\"name\":\"john\",\"city\":\"chicago\",\"age\":\"22\"},{\"name\":\"gary\",\"city\":\"florida\",\"age\":\"35\"},{\"name\":\"sal\",\"city\":\"vegas\",\"age\":\"18\"}]", result.toString());
+    }
+
+    @Test
+    public void givenCommaDelimitedText_thenGetJSONArrayOfJSONObjects2() {
+        JSONArray ja = new JSONArray();
+        ja.put("name");
+        ja.put("city");
+        ja.put("age");
+         
+        String string = 
+          "john, chicago, 22 \n" +
+          "gary, florida, 35 \n" +
+          "sal, vegas, 18";
+         
+        JSONArray result = CDL.toJSONArray(ja, string);
+        assertEquals("[{\"name\":\"john\",\"city\":\"chicago\",\"age\":\"22\"},{\"name\":\"gary\",\"city\":\"florida\",\"age\":\"35\"},{\"name\":\"sal\",\"city\":\"vegas\",\"age\":\"18\"}]", result.toString());
+    }
+    
+}

json/src/test/java/com/baeldung/jsonjava/CookieIntegrationTest.java

@@ -0,0 +1,29 @@
+package com.baeldung.jsonjava;
+
+import static org.junit.Assert.assertEquals;
+
+import org.json.Cookie;
+import org.json.JSONObject;
+import org.junit.Test;
+
+public class CookieIntegrationTest {
+    @Test
+    public void givenCookieString_thenConvertToJSONObject() {
+        String cookie = "username=John Doe; expires=Thu, 18 Dec 2013 12:00:00 UTC; path=/";
+        JSONObject cookieJO = Cookie.toJSONObject(cookie);
+
+        assertEquals("{\"path\":\"/\",\"expires\":\"Thu, 18 Dec 2013 12:00:00 UTC\",\"name\":\"username\",\"value\":\"John Doe\"}", cookieJO.toString());
+    }
+    
+    @Test
+    public void givenJSONObject_thenConvertToCookieString() {
+        JSONObject cookieJO = new JSONObject();
+        cookieJO.put("name", "username");
+        cookieJO.put("value", "John Doe");
+        cookieJO.put("expires", "Thu, 18 Dec 2013 12:00:00 UTC");
+        cookieJO.put("path", "/");
+        String cookie = Cookie.toString(cookieJO);
+
+        assertEquals("username=John Doe;expires=Thu, 18 Dec 2013 12:00:00 UTC;path=/", cookie.toString());
+    }
+}

json/src/test/java/com/baeldung/jsonjava/HTTPIntegrationTest.java

@@ -0,0 +1,25 @@
+package com.baeldung.jsonjava;
+
+import static org.junit.Assert.assertEquals;
+import org.json.HTTP;
+import org.json.JSONObject;
+import org.junit.Test;
+
+public class HTTPIntegrationTest {
+    @Test
+    public void givenJSONObject_thenConvertToHTTPHeader() {
+        JSONObject jo = new JSONObject();
+        jo.put("Method", "POST");
+        jo.put("Request-URI", "http://www.example.com/");
+        jo.put("HTTP-Version", "HTTP/1.1");
+        
+        assertEquals("POST \"http://www.example.com/\" HTTP/1.1"+HTTP.CRLF+HTTP.CRLF, HTTP.toString(jo));
+    }
+
+    @Test
+    public void givenHTTPHeader_thenConvertToJSONObject() {
+        JSONObject obj = HTTP.toJSONObject("POST \"http://www.example.com/\" HTTP/1.1");
+        
+        assertEquals("{\"Request-URI\":\"http://www.example.com/\",\"Method\":\"POST\",\"HTTP-Version\":\"HTTP/1.1\"}", obj.toString());
+    }
+}

json/src/test/java/com/baeldung/jsonjava/JSONArrayIntegrationTest.java

@@ -0,0 +1,47 @@
+package com.baeldung.jsonjava;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.json.JSONArray;
+import org.json.JSONObject;
+import org.junit.Test;
+
+public class JSONArrayIntegrationTest {
+    @Test
+    public void givenJSONJava_thenCreateNewJSONArrayFromScratch() {
+        JSONArray ja = new JSONArray();
+        ja.put(Boolean.TRUE);
+        ja.put("lorem ipsum");
+         
+        // We can also put a JSONObject in JSONArray
+        JSONObject jo = new JSONObject();
+        jo.put("name", "jon doe");
+        jo.put("age", "22");
+        jo.put("city", "chicago");
+         
+        ja.put(jo);
+         
+        assertEquals("[true,\"lorem ipsum\",{\"city\":\"chicago\",\"name\":\"jon doe\",\"age\":\"22\"}]", ja.toString());
+    }
+    
+    @Test
+    public void givenJsonString_thenCreateNewJSONArray() {
+        JSONArray ja = new JSONArray("[true, \"lorem ipsum\", 215]");
+        assertEquals("[true,\"lorem ipsum\",215]", ja.toString());
+    }
+
+    @Test
+    public void givenListObject_thenConvertItToJSONArray() {
+        List<String> list = new ArrayList<>();
+        list.add("California");
+        list.add("Texas");
+        list.add("Hawaii");
+        list.add("Alaska");
+         
+        JSONArray ja = new JSONArray(list);
+        assertEquals("[\"California\",\"Texas\",\"Hawaii\",\"Alaska\"]", ja.toString());
+    }
+}

json/src/test/java/com/baeldung/jsonjava/JSONObjectIntegrationTest.java

@@ -0,0 +1,53 @@
+package com.baeldung.jsonjava;
+
+import static org.junit.Assert.assertEquals;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.json.JSONObject;
+import org.junit.Test;
+
+public class JSONObjectIntegrationTest {
+    @Test
+    public void givenJSONJava_thenCreateNewJSONObject() {
+        JSONObject jo = new JSONObject();
+        jo.put("name", "jon doe");
+        jo.put("age", "22");
+        jo.put("city", "chicago");
+             
+        assertEquals("{\"city\":\"chicago\",\"name\":\"jon doe\",\"age\":\"22\"}", jo.toString());
+        
+    }
+
+    @Test
+    public void givenMapObject_thenCreateJSONObject() {
+        Map<String, String> map = new HashMap<>();
+        map.put("name", "jon doe");
+        map.put("age", "22");
+        map.put("city", "chicago");
+        JSONObject jo = new JSONObject(map);
+         
+        assertEquals("{\"name\":\"jon doe\",\"city\":\"chicago\",\"age\":\"22\"}", jo.toString());
+    }
+
+    @Test
+    public void givenJsonString_thenCreateJSONObject() {
+        JSONObject jo = new JSONObject(
+          "{\"city\":\"chicago\",\"name\":\"jon doe\",\"age\":\"22\"}"
+        );
+        
+        assertEquals("{\"city\":\"chicago\",\"name\":\"jon doe\",\"age\":\"22\"}", jo.toString());
+    }
+
+    @Test
+    public void givenDemoBean_thenCreateJSONObject() {
+        DemoBean demo = new DemoBean();
+        demo.setId(1);
+        demo.setName("lorem ipsum");
+        demo.setActive(true);
+         
+        JSONObject jo = new JSONObject(demo);
+        assertEquals("{\"name\":\"lorem ipsum\",\"active\":true,\"id\":1}", jo.toString());
+    }
+}

json/src/test/java/com/baeldung/jsonjava/JSONTokenerIntegrationTest.java

@@ -0,0 +1,21 @@
+package com.baeldung.jsonjava;
+
+import static org.junit.Assert.assertEquals;
+
+import org.json.JSONTokener;
+import org.junit.Test;
+
+public class JSONTokenerIntegrationTest {
+    @Test
+    public void givenString_convertItToJSONTokens() {
+        String str = "Sample String";
+        JSONTokener jt = new JSONTokener(str);
+        
+        char[] expectedTokens = str.toCharArray();
+        int index = 0;
+        
+        while(jt.more()) {
+            assertEquals(expectedTokens[index++], jt.next());
+        }
+    }
+}

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)
 
 
 

libraries/pom.xml

@@ -116,6 +116,12 @@
         </plugins>
     </build>
     <dependencies>
+    	<!-- https://mvnrepository.com/artifact/org.asynchttpclient/async-http-client -->
+        <dependency>
+            <groupId>org.asynchttpclient</groupId>
+            <artifactId>async-http-client</artifactId>
+            <version>${async.http.client.version}</version>
+        </dependency>
         <!-- https://mvnrepository.com/artifact/org.beykery/neuroph/2.92 -->
         <dependency>
             <groupId>org.beykery</groupId>
@@ -194,6 +200,11 @@
             <artifactId>jetty-servlet</artifactId>
             <version>${jetty.version}</version>
         </dependency>
+		<dependency>
+		    <groupId>org.eclipse.jetty</groupId>
+		    <artifactId>jetty-webapp</artifactId>
+		   	 <version>${jetty.version}</version>
+		</dependency>
         <dependency>
             <groupId>rome</groupId>
             <artifactId>rome</artifactId>
@@ -705,6 +716,18 @@
             <classifier>test</classifier>
             <scope>test</scope>
         </dependency>
+
+        <!-- tomcat -->
+        <dependency>
+            <groupId>org.apache.tomcat</groupId>
+            <artifactId>tomcat-catalina</artifactId>
+            <version>${tomcat.version}</version>
+        </dependency>
+        <dependency>
+            <groupId>org.milyn</groupId>
+            <artifactId>milyn-smooks-all</artifactId>
+            <version>${smooks.version}</version>
+        </dependency>
     </dependencies>
     <repositories>
         <repository>
@@ -741,12 +764,11 @@
         <assertj.version>3.6.2</assertj.version>
         <jsonassert.version>1.5.0</jsonassert.version>
         <javers.version>3.1.0</javers.version>
-        <jetty.version>9.4.3.v20170317</jetty.version>
         <httpclient.version>4.5.3</httpclient.version>
         <commons.io.version>2.5</commons.io.version>
         <commons.dbutils.version>1.6</commons.dbutils.version>
         <h2.version>1.4.196</h2.version>
-        <jetty.version>9.4.2.v20170220</jetty.version>
+        <jetty.version>9.4.8.v20171121</jetty.version>
         <httpclient.version>4.5.3</httpclient.version>
         <commons.io.version>2.5</commons.io.version>
         <flink.version>1.2.0</flink.version>
@@ -757,7 +779,7 @@
         <serenity.jira.version>1.1.3-rc.5</serenity.jira.version>
         <serenity.plugin.version>1.4.0</serenity.plugin.version>
         <jUnitParams.version>1.1.0</jUnitParams.version>
-        <netty.version>4.1.15.Final</netty.version>
+        <netty.version>4.1.20.Final</netty.version>
         <commons.collections.version>4.1</commons.collections.version>
         <junit.version>4.12</junit.version>
         <java-lsh.version>0.10</java-lsh.version>
@@ -785,6 +807,9 @@
         <google-api.version>1.23.0</google-api.version>
         <google-sheets.version>v4-rev493-1.21.0</google-sheets.version>
         <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>

libraries/src/main/java/com/baeldung/jetty/JettyServerFactory.java

@@ -0,0 +1,94 @@
+package com.baeldung.jetty;
+
+import org.eclipse.jetty.server.Handler;
+import org.eclipse.jetty.server.Server;
+import org.eclipse.jetty.server.ServerConnector;
+import org.eclipse.jetty.server.handler.HandlerCollection;
+import org.eclipse.jetty.webapp.WebAppContext;
+
+/**
+ * Simple factory for creating Jetty basic instances.
+ * 
+ * @author Donato Rimenti
+ *
+ */
+public class JettyServerFactory {
+
+	/**
+	 * Exposed context of the app.
+	 */
+	public final static String APP_PATH = "/myApp";
+	
+	/**
+	 * The server port.
+	 */
+	public final static int SERVER_PORT = 13133;
+
+	/**
+	 * Private constructor to avoid instantiation.
+	 */
+	private JettyServerFactory() {
+	}
+
+	/**
+	 * Returns a simple server listening on port 80 with a timeout of 30 seconds
+	 * for connections and no handlers.
+	 * 
+	 * @return a server
+	 */
+	public static Server createBaseServer() {
+		Server server = new Server();
+
+		// Adds a connector for port 80 with a timeout of 30 seconds.
+		ServerConnector connector = new ServerConnector(server);
+		connector.setPort(SERVER_PORT);
+		connector.setHost("127.0.0.1");
+		connector.setIdleTimeout(30000);
+		server.addConnector(connector);
+
+		return server;
+	}
+
+	/**
+	 * Creates a server which delegates the request handling to a web
+	 * application.
+	 * 
+	 * @return a server
+	 */
+	public static Server createWebAppServer() {
+		// Adds an handler to a server and returns it.
+		Server server = createBaseServer();
+		String webAppFolderPath = JettyServerFactory.class.getClassLoader().getResource("jetty-embedded-demo-app.war")
+				.getPath();
+		Handler webAppHandler = new WebAppContext(webAppFolderPath, APP_PATH);
+		server.setHandler(webAppHandler);
+
+		return server;
+	}
+
+	/**
+	 * Creates a server which delegates the request handling to both a logging
+	 * handler and to a web application, in this order.
+	 * 
+	 * @return a server
+	 */
+	public static Server createMultiHandlerServer() {
+		Server server = createBaseServer();
+
+		// Creates the handlers and adds them to the server.
+		HandlerCollection handlers = new HandlerCollection();
+
+		String webAppFolderPath = JettyServerFactory.class.getClassLoader().getResource("jetty-embedded-demo-app.war")
+				.getPath();
+		Handler customRequestHandler = new WebAppContext(webAppFolderPath, APP_PATH);
+		handlers.addHandler(customRequestHandler);
+
+		Handler loggingRequestHandler = new LoggingRequestHandler();
+		handlers.addHandler(loggingRequestHandler);
+
+		server.setHandler(handlers);
+
+		return server;
+	}
+
+}

libraries/src/main/java/com/baeldung/jetty/LoggingRequestHandler.java

@@ -0,0 +1,168 @@
+package com.baeldung.jetty;
+
+import java.io.IOException;
+
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+
+import org.eclipse.jetty.server.Handler;
+import org.eclipse.jetty.server.Request;
+import org.eclipse.jetty.server.Server;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Handler implementation which simply logs that a request has been received.
+ * 
+ * @author Donato Rimenti
+ */
+public class LoggingRequestHandler implements Handler {
+
+	/**
+	 * Logger.
+	 */
+	private final static Logger LOG = LoggerFactory.getLogger(LoggingRequestHandler.class);
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.util.component.LifeCycle#addLifeCycleListener(org.
+	 * eclipse.jetty.util.component.LifeCycle.Listener)
+	 */
+	@Override
+	public void addLifeCycleListener(Listener arg0) {
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.util.component.LifeCycle#isFailed()
+	 */
+	@Override
+	public boolean isFailed() {
+		return false;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.util.component.LifeCycle#isRunning()
+	 */
+	@Override
+	public boolean isRunning() {
+		return true;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.util.component.LifeCycle#isStarted()
+	 */
+	@Override
+	public boolean isStarted() {
+		return true;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.util.component.LifeCycle#isStarting()
+	 */
+	@Override
+	public boolean isStarting() {
+		return false;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.util.component.LifeCycle#isStopped()
+	 */
+	@Override
+	public boolean isStopped() {
+		return false;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.util.component.LifeCycle#isStopping()
+	 */
+	@Override
+	public boolean isStopping() {
+		return false;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see
+	 * org.eclipse.jetty.util.component.LifeCycle#removeLifeCycleListener(org.
+	 * eclipse.jetty.util.component.LifeCycle.Listener)
+	 */
+	@Override
+	public void removeLifeCycleListener(Listener arg0) {
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.util.component.LifeCycle#start()
+	 */
+	@Override
+	public void start() throws Exception {
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.util.component.LifeCycle#stop()
+	 */
+	@Override
+	public void stop() throws Exception {
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.server.Handler#destroy()
+	 */
+	@Override
+	public void destroy() {
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.server.Handler#getServer()
+	 */
+	@Override
+	public Server getServer() {
+		return null;
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.server.Handler#handle(java.lang.String,
+	 * org.eclipse.jetty.server.Request, javax.servlet.http.HttpServletRequest,
+	 * javax.servlet.http.HttpServletResponse)
+	 */
+	@Override
+	public void handle(String arg0, Request arg1, HttpServletRequest arg2, HttpServletResponse arg3)
+			throws IOException, ServletException {
+		LOG.info("Received a new request");
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * 
+	 * @see org.eclipse.jetty.server.Handler#setServer(org.eclipse.jetty.server.
+	 * Server)
+	 */
+	@Override
+	public void setServer(Server server) {
+	}
+
+}

libraries/src/main/java/com/baeldung/netty/ChannelHandlerA.java

@@ -0,0 +1,22 @@
+package com.baeldung.netty;
+
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInboundHandlerAdapter;
+
+import java.util.logging.Logger;
+
+public class ChannelHandlerA extends ChannelInboundHandlerAdapter {
+
+    private Logger logger = Logger.getLogger(getClass().getName());
+
+    @Override
+    public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
+        throw new Exception("Ooops");
+    }
+
+    @Override
+    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+        logger.info("Exception Occurred in ChannelHandler A");
+        ctx.fireExceptionCaught(cause);
+    }
+}

libraries/src/main/java/com/baeldung/netty/ChannelHandlerB.java

@@ -0,0 +1,20 @@
+package com.baeldung.netty;
+
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInboundHandlerAdapter;
+
+import java.util.logging.Logger;
+
+
+public class ChannelHandlerB extends ChannelInboundHandlerAdapter {
+
+    private Logger logger = Logger.getLogger(getClass().getName());
+
+    @Override
+    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
+        logger.info("Exception Handled in ChannelHandler B");
+        logger.info(cause.getLocalizedMessage());
+        //do more exception handling
+        ctx.close();
+    }
+}

libraries/src/main/java/com/baeldung/netty/NettyServerB.java

@@ -0,0 +1,47 @@
+package com.baeldung.netty;
+
+import io.netty.bootstrap.ServerBootstrap;
+import io.netty.channel.ChannelFuture;
+import io.netty.channel.ChannelInitializer;
+import io.netty.channel.ChannelOption;
+import io.netty.channel.EventLoopGroup;
+import io.netty.channel.nio.NioEventLoopGroup;
+import io.netty.channel.socket.SocketChannel;
+import io.netty.channel.socket.nio.NioServerSocketChannel;
+
+public class NettyServerB  {
+
+    private int port;
+
+    private NettyServerB(int port) {
+        this.port = port;
+    }
+
+    private void run() throws Exception {
+
+        EventLoopGroup bossGroup = new NioEventLoopGroup();
+        EventLoopGroup workerGroup = new NioEventLoopGroup();
+
+        try {
+            ServerBootstrap b = new ServerBootstrap();
+            b.group(bossGroup, workerGroup)
+                .channel(NioServerSocketChannel.class)
+                .childHandler(new ChannelInitializer<SocketChannel>() {
+                    public void initChannel(SocketChannel ch) throws Exception {
+                        ch.pipeline().addLast(new ChannelHandlerA(), new ChannelHandlerB());
+                    }
+                })
+                .option(ChannelOption.SO_BACKLOG, 128)
+                .childOption(ChannelOption.SO_KEEPALIVE, true);
+            ChannelFuture f = b.bind(port).sync(); // (7)
+            f.channel().closeFuture().sync();
+        } finally {
+            workerGroup.shutdownGracefully();
+            bossGroup.shutdownGracefully();
+        }
+    }
+
+    public static void main(String[] args) throws Exception {
+        new NettyServerB(8080).run();
+    }
+}

libraries/src/main/java/com/baeldung/smooks/converter/OrderConverter.java

@@ -0,0 +1,45 @@
+package com.baeldung.smooks.converter;
+
+import com.baeldung.smooks.model.Order;
+import org.milyn.Smooks;
+import org.milyn.payload.JavaResult;
+import org.milyn.payload.StringResult;
+import org.xml.sax.SAXException;
+
+import javax.xml.transform.stream.StreamSource;
+import java.io.IOException;
+
+public class OrderConverter {
+
+    public Order convertOrderXMLToOrderObject(String path) throws IOException, SAXException {
+        Smooks smooks = new Smooks(OrderConverter.class.getResourceAsStream("/smooks/smooks-mapping.xml"));
+        try {
+            JavaResult javaResult = new JavaResult();
+            smooks.filterSource(new StreamSource(OrderConverter.class.getResourceAsStream(path)), javaResult);
+            return (Order) javaResult.getBean("order");
+        } finally {
+            smooks.close();
+        }
+    }
+    
+
+    public String convertOrderXMLtoEDIFACT(String path) throws IOException, SAXException {
+        return convertDocumentWithTempalte(path, "/smooks/smooks-transform-edi.xml");
+    }
+
+    public String convertOrderXMLtoEmailMessage(String path) throws IOException, SAXException {
+        return convertDocumentWithTempalte(path, "/smooks/smooks-transform-email.xml");
+    }
+
+    private String convertDocumentWithTempalte(String path, String config) throws IOException, SAXException {
+        Smooks smooks = new Smooks(config);
+
+        try {
+            StringResult stringResult = new StringResult();
+            smooks.filterSource(new StreamSource(OrderConverter.class.getResourceAsStream(path)), stringResult);
+            return stringResult.toString();
+        } finally {
+            smooks.close();
+        }
+    }
+}

libraries/src/main/java/com/baeldung/smooks/converter/OrderValidator.java

@@ -0,0 +1,27 @@
+package com.baeldung.smooks.converter;
+
+import org.milyn.Smooks;
+import org.milyn.payload.JavaResult;
+import org.milyn.payload.StringResult;
+import org.milyn.validation.ValidationResult;
+import org.xml.sax.SAXException;
+
+import javax.xml.transform.stream.StreamSource;
+import java.io.IOException;
+
+public class OrderValidator {
+
+    public ValidationResult validate(String path) throws IOException, SAXException {
+        Smooks smooks = new Smooks(OrderValidator.class.getResourceAsStream("/smooks/smooks-validation.xml"));
+
+        try {
+            StringResult xmlResult = new StringResult();
+            JavaResult javaResult = new JavaResult();
+            ValidationResult validationResult = new ValidationResult();
+            smooks.filterSource(new StreamSource(OrderValidator.class.getResourceAsStream(path)), xmlResult, javaResult, validationResult);
+            return validationResult;
+        } finally {
+            smooks.close();
+        }
+    }
+}

libraries/src/main/java/com/baeldung/smooks/model/Item.java

@@ -0,0 +1,71 @@
+package com.baeldung.smooks.model;
+
+public class Item {
+
+    public Item() {
+    }
+
+    public Item(String code, Double price, Integer quantity) {
+        this.code = code;
+        this.price = price;
+        this.quantity = quantity;
+    }
+
+    private String code;
+    private Double price;
+    private Integer quantity;
+
+
+    public String getCode() {
+        return code;
+    }
+
+    public void setCode(String code) {
+        this.code = code;
+    }
+
+    public Double getPrice() {
+        return price;
+    }
+
+    public void setPrice(Double price) {
+        this.price = price;
+    }
+
+    public Integer getQuantity() {
+        return quantity;
+    }
+
+    public void setQuantity(Integer quantity) {
+        this.quantity = quantity;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        Item item = (Item) o;
+
+        if (code != null ? !code.equals(item.code) : item.code != null) return false;
+        if (price != null ? !price.equals(item.price) : item.price != null) return false;
+        return quantity != null ? quantity.equals(item.quantity) : item.quantity == null;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = code != null ? code.hashCode() : 0;
+        result = 31 * result + (price != null ? price.hashCode() : 0);
+        result = 31 * result + (quantity != null ? quantity.hashCode() : 0);
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "Item{" +
+                "code='" + code + '\'' +
+                ", price=" + price +
+                ", quantity=" + quantity +
+                '}';
+    }
+}

libraries/src/main/java/com/baeldung/smooks/model/Order.java

@@ -0,0 +1,52 @@
+package com.baeldung.smooks.model;
+
+import java.util.Date;
+import java.util.List;
+
+public class Order {
+    private Date creationDate;
+    private Long number;
+    private Status status;
+    private Supplier supplier;
+    private List<Item> items;
+
+    public Date getCreationDate() {
+        return creationDate;
+    }
+
+    public void setCreationDate(Date creationDate) {
+        this.creationDate = creationDate;
+    }
+
+    public Long getNumber() {
+        return number;
+    }
+
+    public void setNumber(Long number) {
+        this.number = number;
+    }
+
+    public Status getStatus() {
+        return status;
+    }
+
+    public void setStatus(Status status) {
+        this.status = status;
+    }
+
+    public Supplier getSupplier() {
+        return supplier;
+    }
+
+    public void setSupplier(Supplier supplier) {
+        this.supplier = supplier;
+    }
+
+    public List<Item> getItems() {
+        return items;
+    }
+
+    public void setItems(List<Item> items) {
+        this.items = items;
+    }
+}

libraries/src/main/java/com/baeldung/smooks/model/Status.java

@@ -0,0 +1,5 @@
+package com.baeldung.smooks.model;
+
+public enum Status {
+    NEW, IN_PROGRESS, FINISHED
+}

libraries/src/main/java/com/baeldung/smooks/model/Supplier.java

@@ -0,0 +1,49 @@
+package com.baeldung.smooks.model;
+
+public class Supplier {
+
+    private String name;
+    private String phoneNumber;
+
+    public Supplier() {
+    }
+
+    public Supplier(String name, String phoneNumber) {
+        this.name = name;
+        this.phoneNumber = phoneNumber;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getPhoneNumber() {
+        return phoneNumber;
+    }
+
+    public void setPhoneNumber(String phoneNumber) {
+        this.phoneNumber = phoneNumber;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) return true;
+        if (o == null || getClass() != o.getClass()) return false;
+
+        Supplier supplier = (Supplier) o;
+
+        if (name != null ? !name.equals(supplier.name) : supplier.name != null) return false;
+        return phoneNumber != null ? phoneNumber.equals(supplier.phoneNumber) : supplier.phoneNumber == null;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = name != null ? name.hashCode() : 0;
+        result = 31 * result + (phoneNumber != null ? phoneNumber.hashCode() : 0);
+        return result;
+    }
+}

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() {
+
+    }
+}

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();
+    }
+}