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Merge remote-tracking branch 'upstream/master'

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This commit is contained in:
Mariusz Kuligowski 2018-03-10 21:47:53 +01:00
commit fdd00c7fdc
1073 changed files with 29025 additions and 4585 deletions
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1
.gitignore vendored
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@ -43,3 +43,4 @@ spring-call-getters-using-reflection/.mvn/wrapper/maven-wrapper.properties
spring-check-if-a-property-is-null/.mvn/wrapper/maven-wrapper.properties
*.springBeans
20171220-JMeter.csv

129
activejdbc/pom.xml Normal file
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@ -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>

61
activejdbc/src/main/java/com/baeldung/ActiveJDBCApp.java Normal file
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@ -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!");
}
}
}

19
activejdbc/src/main/java/com/baeldung/model/Employee.java Normal file
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@ -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);
}
}

18
activejdbc/src/main/java/com/baeldung/model/Role.java Normal file
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@ -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);
}
}

25
activejdbc/src/main/migration/_create_tables.sql Normal file
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@ -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;

10
activejdbc/src/main/resources/database.properties Normal file
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@ -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

51
activejdbc/src/test/java/com/baeldung/ActiveJDBCAppTest.java Normal file
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@ -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();
}
}

1
algorithms/README.md
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@ -16,3 +16,4 @@
- [Introduction to Minimax Algorithm](http://www.baeldung.com/java-minimax-algorithm)
- [How to Calculate Levenshtein Distance in Java?](http://www.baeldung.com/java-levenshtein-distance)
- [How to Find the Kth Largest Element in Java](http://www.baeldung.com/java-kth-largest-element)
- [Multi-Swarm Optimization Algorithm in Java](http://www.baeldung.com/java-multi-swarm-algorithm)

9
algorithms/pom.xml
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@ -9,6 +9,7 @@
<exec-maven-plugin.version>1.5.0</exec-maven-plugin.version>
<lombok.version>1.16.12</lombok.version>
<commons-math3.version>3.6.1</commons-math3.version>
<tradukisto.version>1.0.1</tradukisto.version>
</properties>
<parent>
@ -39,6 +40,11 @@
<artifactId>jgrapht-core</artifactId>
<version>1.0.1</version>
</dependency>
<dependency>
<groupId>pl.allegro.finance</groupId>
<artifactId>tradukisto</artifactId>
<version>${tradukisto.version}</version>
</dependency>
<dependency>
<groupId>org.assertj</groupId>
<artifactId>assertj-core</artifactId>
@ -46,7 +52,6 @@
<scope>test</scope>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
@ -77,4 +82,4 @@
</plugin>
</plugins>
</reporting>
</project>
</project>

52
algorithms/src/main/java/com/baeldung/algorithms/maze/solver/BFSMazeSolver.java Normal file
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@ -0,0 +1,52 @@
package com.baeldung.algorithms.maze.solver;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
public class BFSMazeSolver {
private static final int[][] DIRECTIONS = { { 0, 1 }, { 1, 0 }, { 0, -1 }, { -1, 0 } };
public List<Coordinate> solve(Maze maze) {
LinkedList<Coordinate> nextToVisit = new LinkedList<>();
Coordinate start = maze.getEntry();
nextToVisit.add(start);
while (!nextToVisit.isEmpty()) {
Coordinate cur = nextToVisit.remove();
if (!maze.isValidLocation(cur.getX(), cur.getY()) || maze.isExplored(cur.getX(), cur.getY())) {
continue;
}
if (maze.isWall(cur.getX(), cur.getY())) {
maze.setVisited(cur.getX(), cur.getY(), true);
continue;
}
if (maze.isExit(cur.getX(), cur.getY())) {
return backtrackPath(cur);
}
for (int[] direction : DIRECTIONS) {
Coordinate coordinate = new Coordinate(cur.getX() + direction[0], cur.getY() + direction[1], cur);
nextToVisit.add(coordinate);
maze.setVisited(cur.getX(), cur.getY(), true);
}
}
return Collections.emptyList();
}
private List<Coordinate> backtrackPath(Coordinate cur) {
List<Coordinate> path = new ArrayList<>();
Coordinate iter = cur;
while (iter != null) {
path.add(iter);
iter = iter.parent;
}
return path;
}
}

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algorithms/src/main/java/com/baeldung/algorithms/maze/solver/Coordinate.java Normal file
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@ -0,0 +1,31 @@
package com.baeldung.algorithms.maze.solver;
public class Coordinate {
int x;
int y;
Coordinate parent;
public Coordinate(int x, int y) {
this.x = x;
this.y = y;
this.parent = null;
}
public Coordinate(int x, int y, Coordinate parent) {
this.x = x;
this.y = y;
this.parent = parent;
}
int getX() {
return x;
}
int getY() {
return y;
}
Coordinate getParent() {
return parent;
}
}

48
algorithms/src/main/java/com/baeldung/algorithms/maze/solver/DFSMazeSolver.java Normal file
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@ -0,0 +1,48 @@
package com.baeldung.algorithms.maze.solver;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class DFSMazeSolver {
private static final int[][] DIRECTIONS = { { 0, 1 }, { 1, 0 }, { 0, -1 }, { -1, 0 } };
public List<Coordinate> solve(Maze maze) {
List<Coordinate> path = new ArrayList<>();
if (explore(maze, maze.getEntry()
.getX(),
maze.getEntry()
.getY(),
path)) {
return path;
}
return Collections.emptyList();
}
private boolean explore(Maze maze, int row, int col, List<Coordinate> path) {
if (!maze.isValidLocation(row, col) || maze.isWall(row, col) || maze.isExplored(row, col)) {
return false;
}
path.add(new Coordinate(row, col));
maze.setVisited(row, col, true);
if (maze.isExit(row, col)) {
return true;
}
for (int[] direction : DIRECTIONS) {
Coordinate coordinate = getNextCoordinate(row, col, direction[0], direction[1]);
if (explore(maze, coordinate.getX(), coordinate.getY(), path)) {
return true;
}
}
path.remove(path.size() - 1);
return false;
}
private Coordinate getNextCoordinate(int row, int col, int i, int j) {
return new Coordinate(row + i, col + j);
}
}

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algorithms/src/main/java/com/baeldung/algorithms/maze/solver/Maze.java Normal file
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@ -0,0 +1,141 @@
package com.baeldung.algorithms.maze.solver;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
public class Maze {
private static final int ROAD = 0;
private static final int WALL = 1;
private static final int START = 2;
private static final int EXIT = 3;
private static final int PATH = 4;
private int[][] maze;
private boolean[][] visited;
private Coordinate start;
private Coordinate end;
public Maze(File maze) throws FileNotFoundException {
String fileText = "";
try (Scanner input = new Scanner(maze)) {
while (input.hasNextLine()) {
fileText += input.nextLine() + "\n";
}
}
initializeMaze(fileText);
}
private void initializeMaze(String text) {
if (text == null || (text = text.trim()).length() == 0) {
throw new IllegalArgumentException("empty lines data");
}
String[] lines = text.split("[\r]?\n");
maze = new int[lines.length][lines[0].length()];
visited = new boolean[lines.length][lines[0].length()];
for (int row = 0; row < getHeight(); row++) {
if (lines[row].length() != getWidth()) {
throw new IllegalArgumentException("line " + (row + 1) + " wrong length (was " + lines[row].length() + " but should be " + getWidth() + ")");
}
for (int col = 0; col < getWidth(); col++) {
if (lines[row].charAt(col) == '#')
maze[row][col] = WALL;
else if (lines[row].charAt(col) == 'S') {
maze[row][col] = START;
start = new Coordinate(row, col);
} else if (lines[row].charAt(col) == 'E') {
maze[row][col] = EXIT;
end = new Coordinate(row, col);
} else
maze[row][col] = ROAD;
}
}
}
public int getHeight() {
return maze.length;
}
public int getWidth() {
return maze[0].length;
}
public Coordinate getEntry() {
return start;
}
public Coordinate getExit() {
return end;
}
public boolean isExit(int x, int y) {
return x == end.getX() && y == end.getY();
}
public boolean isStart(int x, int y) {
return x == start.getX() && y == start.getY();
}
public boolean isExplored(int row, int col) {
return visited[row][col];
}
public boolean isWall(int row, int col) {
return maze[row][col] == WALL;
}
public void setVisited(int row, int col, boolean value) {
visited[row][col] = value;
}
public boolean isValidLocation(int row, int col) {
if (row < 0 || row >= getHeight() || col < 0 || col >= getWidth()) {
return false;
}
return true;
}
public void printPath(List<Coordinate> path) {
int[][] tempMaze = Arrays.stream(maze)
.map(int[]::clone)
.toArray(int[][]::new);
for (Coordinate coordinate : path) {
if (isStart(coordinate.getX(), coordinate.getY()) || isExit(coordinate.getX(), coordinate.getY())) {
continue;
}
tempMaze[coordinate.getX()][coordinate.getY()] = PATH;
}
System.out.println(toString(tempMaze));
}
public String toString(int[][] maze) {
StringBuilder result = new StringBuilder(getWidth() * (getHeight() + 1));
for (int row = 0; row < getHeight(); row++) {
for (int col = 0; col < getWidth(); col++) {
if (maze[row][col] == ROAD) {
result.append(' ');
} else if (maze[row][col] == WALL) {
result.append('#');
} else if (maze[row][col] == START) {
result.append('S');
} else if (maze[row][col] == EXIT) {
result.append('E');
} else {
result.append('.');
}
}
result.append('\n');
}
return result.toString();
}
public void reset() {
for (int i = 0; i < visited.length; i++)
Arrays.fill(visited[i], false);
}
}

34
algorithms/src/main/java/com/baeldung/algorithms/maze/solver/MazeDriver.java Normal file
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@ -0,0 +1,34 @@
package com.baeldung.algorithms.maze.solver;
import java.io.File;
import java.util.List;
public class MazeDriver {
public static void main(String[] args) throws Exception {
File maze1 = new File("src/main/resources/maze/maze1.txt");
File maze2 = new File("src/main/resources/maze/maze2.txt");
execute(maze1);
execute(maze2);
}
private static void execute(File file) throws Exception {
Maze maze = new Maze(file);
dfs(maze);
bfs(maze);
}
private static void bfs(Maze maze) {
BFSMazeSolver bfs = new BFSMazeSolver();
List<Coordinate> path = bfs.solve(maze);
maze.printPath(path);
maze.reset();
}
private static void dfs(Maze maze) {
DFSMazeSolver dfs = new DFSMazeSolver();
List<Coordinate> path = dfs.solve(maze);
maze.printPath(path);
maze.reset();
}
}

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algorithms/src/main/java/com/baeldung/algorithms/multiswarm/Constants.java Normal file
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@ -0,0 +1,47 @@
package com.baeldung.algorithms.multiswarm;
/**
* Constants used by the Multi-swarm optimization algorithms.
*
* @author Donato Rimenti
*
*/
public class Constants {
/**
* The inertia factor encourages a particle to continue moving in its
* current direction.
*/
public static final double INERTIA_FACTOR = 0.729;
/**
* The cognitive weight encourages a particle to move toward its historical
* best-known position.
*/
public static final double COGNITIVE_WEIGHT = 1.49445;
/**
* The social weight encourages a particle to move toward the best-known
* position found by any of the particle’s swarm-mates.
*/
public static final double SOCIAL_WEIGHT = 1.49445;
/**
* The global weight encourages a particle to move toward the best-known
* position found by any particle in any swarm.
*/
public static final double GLOBAL_WEIGHT = 0.3645;
/**
* Upper bound for the random generation. We use it to reduce the
* computation time since we can rawly estimate it.
*/
public static final int PARTICLE_UPPER_BOUND = 10000000;
/**
* Private constructor for utility class.
*/
private Constants() {
}
}

21
algorithms/src/main/java/com/baeldung/algorithms/multiswarm/FitnessFunction.java Normal file
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@ -0,0 +1,21 @@
package com.baeldung.algorithms.multiswarm;
/**
* Interface for a fitness function, used to decouple the main algorithm logic
* from the specific problem solution.
*
* @author Donato Rimenti
*
*/
public interface FitnessFunction {
/**
* Returns the fitness of a particle given its position.
*
* @param particlePosition
* the position of the particle
* @return the fitness of the particle
*/
public double getFitness(long[] particlePosition);
}

227
algorithms/src/main/java/com/baeldung/algorithms/multiswarm/Multiswarm.java Normal file
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@ -0,0 +1,227 @@
package com.baeldung.algorithms.multiswarm;
import java.util.Arrays;
import java.util.Random;
/**
* Represents a collection of {@link Swarm}.
*
* @author Donato Rimenti
*
*/
public class Multiswarm {
/**
* The swarms managed by this multiswarm.
*/
private Swarm[] swarms;
/**
* The best position found within all the {@link #swarms}.
*/
private long[] bestPosition;
/**
* The best fitness score found within all the {@link #swarms}.
*/
private double bestFitness = Double.NEGATIVE_INFINITY;
/**
* A random generator.
*/
private Random random = new Random();
/**
* The fitness function used to determine how good is a particle.
*/
private FitnessFunction fitnessFunction;
/**
* Instantiates a new Multiswarm.
*
* @param numSwarms
* the number of {@link #swarms}
* @param particlesPerSwarm
* the number of particle for each {@link #swarms}
* @param fitnessFunction
* the {@link #fitnessFunction}
*/
public Multiswarm(int numSwarms, int particlesPerSwarm, FitnessFunction fitnessFunction) {
this.fitnessFunction = fitnessFunction;
this.swarms = new Swarm[numSwarms];
for (int i = 0; i < numSwarms; i++) {
swarms[i] = new Swarm(particlesPerSwarm);
}
}
/**
* Main loop of the algorithm. Iterates all particles of all
* {@link #swarms}. For each particle, computes the new fitness and checks
* if a new best position has been found among itself, the swarm and all the
* swarms and finally updates the particle position and speed.
*/
public void mainLoop() {
for (Swarm swarm : swarms) {
for (Particle particle : swarm.getParticles()) {
long[] particleOldPosition = particle.getPosition().clone();
// Calculate the particle fitness.
particle.setFitness(fitnessFunction.getFitness(particleOldPosition));
// Check if a new best position has been found for the particle
// itself, within the swarm and the multiswarm.
if (particle.getFitness() > particle.getBestFitness()) {
particle.setBestFitness(particle.getFitness());
particle.setBestPosition(particleOldPosition);
if (particle.getFitness() > swarm.getBestFitness()) {
swarm.setBestFitness(particle.getFitness());
swarm.setBestPosition(particleOldPosition);
if (swarm.getBestFitness() > bestFitness) {
bestFitness = swarm.getBestFitness();
bestPosition = swarm.getBestPosition().clone();
}
}
}
// Updates the particle position by adding the speed to the
// actual position.
long[] position = particle.getPosition();
long[] speed = particle.getSpeed();
position[0] += speed[0];
position[1] += speed[1];
// Updates the particle speed.
speed[0] = getNewParticleSpeedForIndex(particle, swarm, 0);
speed[1] = getNewParticleSpeedForIndex(particle, swarm, 1);
}
}
}
/**
* Computes a new speed for a given particle of a given swarm on a given
* axis. The new speed is computed using the formula:
*
* <pre>
* ({@link Constants#INERTIA_FACTOR} * {@link Particle#getSpeed()}) +
* (({@link Constants#COGNITIVE_WEIGHT} * random(0,1)) * ({@link Particle#getBestPosition()} - {@link Particle#getPosition()})) +
* (({@link Constants#SOCIAL_WEIGHT} * random(0,1)) * ({@link Swarm#getBestPosition()} - {@link Particle#getPosition()})) +
* (({@link Constants#GLOBAL_WEIGHT} * random(0,1)) * ({@link #bestPosition} - {@link Particle#getPosition()}))
* </pre>
*
* @param particle
* the particle whose new speed needs to be computed
* @param swarm
* the swarm which contains the particle
* @param index
* the index of the particle axis whose speeds needs to be
* computed
* @return the new speed of the particle passed on the given axis
*/
private int getNewParticleSpeedForIndex(Particle particle, Swarm swarm, int index) {
return (int) ((Constants.INERTIA_FACTOR * particle.getSpeed()[index])
+ (randomizePercentage(Constants.COGNITIVE_WEIGHT)
* (particle.getBestPosition()[index] - particle.getPosition()[index]))
+ (randomizePercentage(Constants.SOCIAL_WEIGHT)
* (swarm.getBestPosition()[index] - particle.getPosition()[index]))
+ (randomizePercentage(Constants.GLOBAL_WEIGHT)
* (bestPosition[index] - particle.getPosition()[index])));
}
/**
* Returns a random number between 0 and the value passed as argument.
*
* @param value
* the value to randomize
* @return a random value between 0 and the one passed as argument
*/
private double randomizePercentage(double value) {
return random.nextDouble() * value;
}
/**
* Gets the {@link #bestPosition}.
*
* @return the {@link #bestPosition}
*/
public long[] getBestPosition() {
return bestPosition;
}
/**
* Gets the {@link #bestFitness}.
*
* @return the {@link #bestFitness}
*/
public double getBestFitness() {
return bestFitness;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
long temp;
temp = Double.doubleToLongBits(bestFitness);
result = prime * result + (int) (temp ^ (temp >>> 32));
result = prime * result + Arrays.hashCode(bestPosition);
result = prime * result + ((fitnessFunction == null) ? 0 : fitnessFunction.hashCode());
result = prime * result + ((random == null) ? 0 : random.hashCode());
result = prime * result + Arrays.hashCode(swarms);
return result;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Multiswarm other = (Multiswarm) obj;
if (Double.doubleToLongBits(bestFitness) != Double.doubleToLongBits(other.bestFitness))
return false;
if (!Arrays.equals(bestPosition, other.bestPosition))
return false;
if (fitnessFunction == null) {
if (other.fitnessFunction != null)
return false;
} else if (!fitnessFunction.equals(other.fitnessFunction))
return false;
if (random == null) {
if (other.random != null)
return false;
} else if (!random.equals(other.random))
return false;
if (!Arrays.equals(swarms, other.swarms))
return false;
return true;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "Multiswarm [swarms=" + Arrays.toString(swarms) + ", bestPosition=" + Arrays.toString(bestPosition)
+ ", bestFitness=" + bestFitness + ", random=" + random + ", fitnessFunction=" + fitnessFunction + "]";
}
}

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algorithms/src/main/java/com/baeldung/algorithms/multiswarm/Particle.java Normal file
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package com.baeldung.algorithms.multiswarm;
import java.util.Arrays;
/**
* Represents a particle, the basic component of a {@link Swarm}.
*
* @author Donato Rimenti
*
*/
public class Particle {
/**
* The current position of this particle.
*/
private long[] position;
/**
* The speed of this particle.
*/
private long[] speed;
/**
* The fitness of this particle for the current position.
*/
private double fitness;
/**
* The best position found by this particle.
*/
private long[] bestPosition;
/**
* The best fitness found by this particle.
*/
private double bestFitness = Double.NEGATIVE_INFINITY;
/**
* Instantiates a new Particle.
*
* @param initialPosition
* the initial {@link #position}
* @param initialSpeed
* the initial {@link #speed}
*/
public Particle(long[] initialPosition, long[] initialSpeed) {
this.position = initialPosition;
this.speed = initialSpeed;
}
/**
* Gets the {@link #position}.
*
* @return the {@link #position}
*/
public long[] getPosition() {
return position;
}
/**
* Gets the {@link #speed}.
*
* @return the {@link #speed}
*/
public long[] getSpeed() {
return speed;
}
/**
* Gets the {@link #fitness}.
*
* @return the {@link #fitness}
*/
public double getFitness() {
return fitness;
}
/**
* Gets the {@link #bestPosition}.
*
* @return the {@link #bestPosition}
*/
public long[] getBestPosition() {
return bestPosition;
}
/**
* Gets the {@link #bestFitness}.
*
* @return the {@link #bestFitness}
*/
public double getBestFitness() {
return bestFitness;
}
/**
* Sets the {@link #position}.
*
* @param position
* the new {@link #position}
*/
public void setPosition(long[] position) {
this.position = position;
}
/**
* Sets the {@link #speed}.
*
* @param speed
* the new {@link #speed}
*/
public void setSpeed(long[] speed) {
this.speed = speed;
}
/**
* Sets the {@link #fitness}.
*
* @param fitness
* the new {@link #fitness}
*/
public void setFitness(double fitness) {
this.fitness = fitness;
}
/**
* Sets the {@link #bestPosition}.
*
* @param bestPosition
* the new {@link #bestPosition}
*/
public void setBestPosition(long[] bestPosition) {
this.bestPosition = bestPosition;
}
/**
* Sets the {@link #bestFitness}.
*
* @param bestFitness
* the new {@link #bestFitness}
*/
public void setBestFitness(double bestFitness) {
this.bestFitness = bestFitness;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
long temp;
temp = Double.doubleToLongBits(bestFitness);
result = prime * result + (int) (temp ^ (temp >>> 32));
result = prime * result + Arrays.hashCode(bestPosition);
temp = Double.doubleToLongBits(fitness);
result = prime * result + (int) (temp ^ (temp >>> 32));
result = prime * result + Arrays.hashCode(position);
result = prime * result + Arrays.hashCode(speed);
return result;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Particle other = (Particle) obj;
if (Double.doubleToLongBits(bestFitness) != Double.doubleToLongBits(other.bestFitness))
return false;
if (!Arrays.equals(bestPosition, other.bestPosition))
return false;
if (Double.doubleToLongBits(fitness) != Double.doubleToLongBits(other.fitness))
return false;
if (!Arrays.equals(position, other.position))
return false;
if (!Arrays.equals(speed, other.speed))
return false;
return true;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "Particle [position=" + Arrays.toString(position) + ", speed=" + Arrays.toString(speed) + ", fitness="
+ fitness + ", bestPosition=" + Arrays.toString(bestPosition) + ", bestFitness=" + bestFitness + "]";
}
}

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algorithms/src/main/java/com/baeldung/algorithms/multiswarm/Swarm.java Normal file
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package com.baeldung.algorithms.multiswarm;
import java.util.Arrays;
import java.util.Random;
/**
* Represents a collection of {@link Particle}.
*
* @author Donato Rimenti
*
*/
public class Swarm {
/**
* The particles of this swarm.
*/
private Particle[] particles;
/**
* The best position found within the particles of this swarm.
*/
private long[] bestPosition;
/**
* The best fitness score found within the particles of this swarm.
*/
private double bestFitness = Double.NEGATIVE_INFINITY;
/**
* A random generator.
*/
private Random random = new Random();
/**
* Instantiates a new Swarm.
*
* @param numParticles
* the number of particles of the swarm
*/
public Swarm(int numParticles) {
particles = new Particle[numParticles];
for (int i = 0; i < numParticles; i++) {
long[] initialParticlePosition = { random.nextInt(Constants.PARTICLE_UPPER_BOUND),
random.nextInt(Constants.PARTICLE_UPPER_BOUND) };
long[] initialParticleSpeed = { random.nextInt(Constants.PARTICLE_UPPER_BOUND),
random.nextInt(Constants.PARTICLE_UPPER_BOUND) };
particles[i] = new Particle(initialParticlePosition, initialParticleSpeed);
}
}
/**
* Gets the {@link #particles}.
*
* @return the {@link #particles}
*/
public Particle[] getParticles() {
return particles;
}
/**
* Gets the {@link #bestPosition}.
*
* @return the {@link #bestPosition}
*/
public long[] getBestPosition() {
return bestPosition;
}
/**
* Gets the {@link #bestFitness}.
*
* @return the {@link #bestFitness}
*/
public double getBestFitness() {
return bestFitness;
}
/**
* Sets the {@link #bestPosition}.
*
* @param bestPosition
* the new {@link #bestPosition}
*/
public void setBestPosition(long[] bestPosition) {
this.bestPosition = bestPosition;
}
/**
* Sets the {@link #bestFitness}.
*
* @param bestFitness
* the new {@link #bestFitness}
*/
public void setBestFitness(double bestFitness) {
this.bestFitness = bestFitness;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
long temp;
temp = Double.doubleToLongBits(bestFitness);
result = prime * result + (int) (temp ^ (temp >>> 32));
result = prime * result + Arrays.hashCode(bestPosition);
result = prime * result + Arrays.hashCode(particles);
result = prime * result + ((random == null) ? 0 : random.hashCode());
return result;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
Swarm other = (Swarm) obj;
if (Double.doubleToLongBits(bestFitness) != Double.doubleToLongBits(other.bestFitness))
return false;
if (!Arrays.equals(bestPosition, other.bestPosition))
return false;
if (!Arrays.equals(particles, other.particles))
return false;
if (random == null) {
if (other.random != null)
return false;
} else if (!random.equals(other.random))
return false;
return true;
}
/*
* (non-Javadoc)
*
* @see java.lang.Object#toString()
*/
@Override
public String toString() {
return "Swarm [particles=" + Arrays.toString(particles) + ", bestPosition=" + Arrays.toString(bestPosition)
+ ", bestFitness=" + bestFitness + ", random=" + random + "]";
}
}

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algorithms/src/main/java/com/baeldung/algorithms/numberwordconverter/NumberWordConverter.java Normal file
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package com.baeldung.algorithms.numberwordconverter;
import java.math.BigDecimal;
import pl.allegro.finance.tradukisto.MoneyConverters;
public class NumberWordConverter {
public static final String INVALID_INPUT_GIVEN = "Invalid input given";
public static final String[] ones = { "", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "twelve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen" };
public static final String[] tens = {
"", // 0
"", // 1
"twenty", // 2
"thirty", // 3
"forty", // 4
"fifty", // 5
"sixty", // 6
"seventy", // 7
"eighty", // 8
"ninety" // 9
};
public static String getMoneyIntoWords(String input) {
MoneyConverters converter = MoneyConverters.ENGLISH_BANKING_MONEY_VALUE;
return converter.asWords(new BigDecimal(input));
}
public static String getMoneyIntoWords(final double money) {
long dollar = (long) money;
long cents = Math.round((money - dollar) * 100);
if (money == 0D) {
return "";
}
if (money < 0) {
return INVALID_INPUT_GIVEN;
}
String dollarPart = "";
if (dollar > 0) {
dollarPart = convert(dollar) + " dollar" + (dollar == 1 ? "" : "s");
}
String centsPart = "";
if (cents > 0) {
if (dollarPart.length() > 0) {
centsPart = " and ";
}
centsPart += convert(cents) + " cent" + (cents == 1 ? "" : "s");
}
return dollarPart + centsPart;
}
private static String convert(final long n) {
if (n < 0) {
return INVALID_INPUT_GIVEN;
}
if (n < 20) {
return ones[(int) n];
}
if (n < 100) {
return tens[(int) n / 10] + ((n % 10 != 0) ? " " : "") + ones[(int) n % 10];
}
if (n < 1000) {
return ones[(int) n / 100] + " hundred" + ((n % 100 != 0) ? " " : "") + convert(n % 100);
}
if (n < 1_000_000) {
return convert(n / 1000) + " thousand" + ((n % 1000 != 0) ? " " : "") + convert(n % 1000);
}
if (n < 1_000_000_000) {
return convert(n / 1_000_000) + " million" + ((n % 1_000_000 != 0) ? " " : "") + convert(n % 1_000_000);
}
return convert(n / 1_000_000_000) + " billion" + ((n % 1_000_000_000 != 0) ? " " : "") + convert(n % 1_000_000_000);
}
}

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algorithms/src/main/java/com/baeldung/algorithms/sudoku/BacktrackingAlgorithm.java Normal file
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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 row = BOARD_START_INDEX; row < BOARD_SIZE; row++) {
for (int column = BOARD_START_INDEX; column < BOARD_SIZE; column++) {
if (board[row][column] == NO_VALUE) {
for (int k = MIN_VALUE; k <= MAX_VALUE; k++) {
board[row][column] = k;
if (isValid(board, row, column) && solve(board)) {
return true;
}
board[row][column] = NO_VALUE;
}
return false;
}
}
}
return true;
}
private boolean isValid(int[][] board, int row, int column) {
return rowConstraint(board, row) &&
columnConstraint(board, column) &&
subsectionConstraint(board, row, column);
}
private boolean subsectionConstraint(int[][] board, int row, int column) {
boolean[] constraint = new boolean[BOARD_SIZE];
int subsectionRowStart = (row / SUBSECTION_SIZE) * SUBSECTION_SIZE;
int subsectionRowEnd = subsectionRowStart + SUBSECTION_SIZE;
int subsectionColumnStart = (column / SUBSECTION_SIZE) * SUBSECTION_SIZE;
int subsectionColumnEnd = subsectionColumnStart + SUBSECTION_SIZE;
for (int r = subsectionRowStart; r < subsectionRowEnd; r++) {
for (int c = subsectionColumnStart; c < subsectionColumnEnd; c++) {
if (!checkConstraint(board, r, constraint, c)) return false;
}
}
return true;
}
private boolean columnConstraint(int[][] board, int column) {
boolean[] constraint = new boolean[BOARD_SIZE];
return IntStream.range(BOARD_START_INDEX, BOARD_SIZE)
.allMatch(row -> checkConstraint(board, row, constraint, column));
}
private boolean rowConstraint(int[][] board, int row) {
boolean[] constraint = new boolean[BOARD_SIZE];
return IntStream.range(BOARD_START_INDEX, BOARD_SIZE)
.allMatch(column -> checkConstraint(board, row, constraint, column));
}
private boolean checkConstraint(int[][] board, int row, boolean[] constraint, int column) {
if (board[row][column] != NO_VALUE) {
if (!constraint[board[row][column] - 1]) {
constraint[board[row][column] - 1] = true;
} else {
return false;
}
}
return true;
}
}

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algorithms/src/main/java/com/baeldung/algorithms/sudoku/ColumnNode.java Normal file
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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();
}
}

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algorithms/src/main/java/com/baeldung/algorithms/sudoku/DancingLinks.java Normal file
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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 size = result.length;
for (int[] aResult : result) {
StringBuilder ret = new StringBuilder();
for (int j = 0; j < size; j++) {
ret.append(aResult[j]).append(" ");
}
System.out.println(ret);
}
System.out.println();
}
}

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algorithms/src/main/java/com/baeldung/algorithms/sudoku/DancingLinksAlgorithm.java Normal file
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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 column, int num) {
return (row - 1) * BOARD_SIZE * BOARD_SIZE + (column - 1) * BOARD_SIZE + (num - 1);
}
private boolean[][] createExactCoverBoard() {
boolean[][] coverBoard = new boolean[BOARD_SIZE * BOARD_SIZE * MAX_VALUE][BOARD_SIZE * BOARD_SIZE * CONSTRAINTS];
int hBase = 0;
hBase = checkCellConstraint(coverBoard, hBase);
hBase = checkRowConstraint(coverBoard, hBase);
hBase = checkColumnConstraint(coverBoard, hBase);
checkSubsectionConstraint(coverBoard, hBase);
return coverBoard;
}
private int checkSubsectionConstraint(boolean[][] coverBoard, int hBase) {
for (int row = COVER_START_INDEX; row <= BOARD_SIZE; row += SUBSECTION_SIZE) {
for (int column = COVER_START_INDEX; column <= BOARD_SIZE; column += SUBSECTION_SIZE) {
for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++, hBase++) {
for (int rowDelta = 0; rowDelta < SUBSECTION_SIZE; rowDelta++) {
for (int columnDelta = 0; columnDelta < SUBSECTION_SIZE; columnDelta++) {
int index = getIndex(row + rowDelta, column + columnDelta, n);
coverBoard[index][hBase] = true;
}
}
}
}
}
return hBase;
}
private int checkColumnConstraint(boolean[][] coverBoard, int hBase) {
for (int column = COVER_START_INDEX; column <= BOARD_SIZE; column++) {
for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++, hBase++) {
for (int row = COVER_START_INDEX; row <= BOARD_SIZE; row++) {
int index = getIndex(row, column, n);
coverBoard[index][hBase] = true;
}
}
}
return hBase;
}
private int checkRowConstraint(boolean[][] coverBoard, int hBase) {
for (int row = COVER_START_INDEX; row <= BOARD_SIZE; row++) {
for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++, hBase++) {
for (int column = COVER_START_INDEX; column <= BOARD_SIZE; column++) {
int index = getIndex(row, column, n);
coverBoard[index][hBase] = true;
}
}
}
return hBase;
}
private int checkCellConstraint(boolean[][] coverBoard, int hBase) {
for (int row = COVER_START_INDEX; row <= BOARD_SIZE; row++) {
for (int column = COVER_START_INDEX; column <= BOARD_SIZE; column++, hBase++) {
for (int n = COVER_START_INDEX; n <= BOARD_SIZE; n++) {
int index = getIndex(row, column, n);
coverBoard[index][hBase] = true;
}
}
}
return hBase;
}
private boolean[][] initializeExactCoverBoard(int[][] board) {
boolean[][] coverBoard = createExactCoverBoard();
for (int row = COVER_START_INDEX; row <= BOARD_SIZE; row++) {
for (int column = COVER_START_INDEX; column <= BOARD_SIZE; column++) {
int n = board[row - 1][column - 1];
if (n != NO_VALUE) {
for (int num = MIN_VALUE; num <= MAX_VALUE; num++) {
if (num != n) {
Arrays.fill(coverBoard[getIndex(row, column, num)], false);
}
}
}
}
}
return coverBoard;
}
}

50
algorithms/src/main/java/com/baeldung/algorithms/sudoku/DancingNode.java Normal file
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package com.baeldung.algorithms.sudoku;
class DancingNode {
DancingNode L, R, U, D;
ColumnNode C;
DancingNode hookDown(DancingNode node) {
assert (this.C == node.C);
node.D = this.D;
node.D.U = node;
node.U = this;
this.D = node;
return node;
}
DancingNode hookRight(DancingNode node) {
node.R = this.R;
node.R.L = node;
node.L = this;
this.R = node;
return node;
}
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;
}
}

12
algorithms/src/main/resources/maze/maze1.txt Normal file
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@ -0,0 +1,12 @@
S ########
# #
# ### ## #
# # # #
# # # # #
# ## #####
# # #
# # # # #
##### ####
# # E
# # # #
##########

22
algorithms/src/main/resources/maze/maze2.txt Normal file
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@ -0,0 +1,22 @@
S ##########################
# # # #
# # #### ############### #
# # # # # #
# # #### # # ###############
# # # # # # #
# # # #### ### ########### #
# # # # # #
# ################## #
######### # # # # #
# # #### # ####### # #
# # ### ### # # # # #
# # ## # ##### # #
##### ####### # # # # #
# # ## ## #### # #
# ##### ####### # #
# # ############
####### ######### # #
# # ######## #
# ####### ###### ## # E
# # # ## #
############################

84
algorithms/src/test/java/com/baeldung/algorithms/moneywords/NumberWordConverterTest.java Normal file
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package com.baeldung.algorithms.moneywords;
import static org.junit.Assert.assertEquals;
import org.junit.Test;
import com.baeldung.algorithms.numberwordconverter.NumberWordConverter;
public class NumberWordConverterTest {
@Test
public void whenMoneyNegative_thenReturnInvalidInput() {
assertEquals(NumberWordConverter.INVALID_INPUT_GIVEN, NumberWordConverter.getMoneyIntoWords(-13));
}
@Test
public void whenZeroDollarsGiven_thenReturnEmptyString() {
assertEquals("", NumberWordConverter.getMoneyIntoWords(0));
}
@Test
public void whenOnlyDollarsGiven_thenReturnWords() {
assertEquals("one dollar", NumberWordConverter.getMoneyIntoWords(1));
}
@Test
public void whenOnlyCentsGiven_thenReturnWords() {
assertEquals("sixty cents", NumberWordConverter.getMoneyIntoWords(0.6));
}
@Test
public void whenAlmostAMillioDollarsGiven_thenReturnWords() {
String expectedResult = "nine hundred ninety nine thousand nine hundred ninety nine dollars";
assertEquals(expectedResult, NumberWordConverter.getMoneyIntoWords(999_999));
}
@Test
public void whenThirtyMillionDollarsGiven_thenReturnWords() {
String expectedResult = "thirty three million three hundred forty eight thousand nine hundred seventy eight dollars";
assertEquals(expectedResult, NumberWordConverter.getMoneyIntoWords(33_348_978));
}
@Test
public void whenTwoBillionDollarsGiven_thenReturnWords() {
String expectedResult = "two billion one hundred thirty three million two hundred forty seven thousand eight hundred ten dollars";
assertEquals(expectedResult, NumberWordConverter.getMoneyIntoWords(2_133_247_810));
}
@Test
public void whenGivenDollarsAndCents_thenReturnWords() {
String expectedResult = "nine hundred twenty four dollars and sixty cents";
assertEquals(expectedResult, NumberWordConverter.getMoneyIntoWords(924.6));
}
@Test
public void whenOneDollarAndNoCents_thenReturnDollarSingular() {
assertEquals("one dollar", NumberWordConverter.getMoneyIntoWords(1));
}
@Test
public void whenNoDollarsAndOneCent_thenReturnCentSingular() {
assertEquals("one cent", NumberWordConverter.getMoneyIntoWords(0.01));
}
@Test
public void whenNoDollarsAndTwoCents_thenReturnCentsPlural() {
assertEquals("two cents", NumberWordConverter.getMoneyIntoWords(0.02));
}
@Test
public void whenNoDollarsAndNinetyNineCents_thenReturnWords() {
assertEquals("ninety nine cents", NumberWordConverter.getMoneyIntoWords(0.99));
}
@Test
public void whenNoDollarsAndNineFiveNineCents_thenCorrectRounding() {
assertEquals("ninety six cents", NumberWordConverter.getMoneyIntoWords(0.959));
}
@Test
public void whenGivenDollarsAndCents_thenReturnWordsVersionTwo() {
assertEquals("three hundred ten £ 00/100", NumberWordConverter.getMoneyIntoWords("310"));
}
}

52
algorithms/src/test/java/com/baeldung/algorithms/multiswarm/LolFitnessFunction.java Normal file
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package com.baeldung.algorithms.multiswarm;
/**
* Specific fitness function implementation to solve the League of Legends
* problem. This is the problem statement: <br>
* <br>
* In League of Legends, a player's Effective Health when defending against
* physical damage is given by E=H(100+A)/100, where H is health and A is armor.
* Health costs 2.5 gold per unit, and Armor costs 18 gold per unit. You have
* 3600 gold, and you need to optimize the effectiveness E of your health and
* armor to survive as long as possible against the enemy team's attacks. How
* much of each should you buy? <br>
* <br>
*
* @author Donato Rimenti
*
*/
public class LolFitnessFunction implements FitnessFunction {
/*
* (non-Javadoc)
*
* @see
* com.baeldung.algorithms.multiswarm.FitnessFunction#getFitness(long[])
*/
@Override
public double getFitness(long[] particlePosition) {
long health = particlePosition[0];
long armor = particlePosition[1];
// No negatives values accepted.
if (health < 0 && armor < 0) {
return -(health * armor);
} else if (health < 0) {
return health;
} else if (armor < 0) {
return armor;
}
// Checks if the solution is actually feasible provided our gold.
double cost = (health * 2.5) + (armor * 18);
if (cost > 3600) {
return 3600 - cost;
} else {
// Check how good is the solution.
long fitness = (health * (100 + armor)) / 100;
return fitness;
}
}
}

54
algorithms/src/test/java/com/baeldung/algorithms/multiswarm/MultiswarmUnitTest.java Normal file
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package com.baeldung.algorithms.multiswarm;
import org.junit.Assert;
import org.junit.Rule;
import org.junit.Test;
import com.baeldung.algorithms.support.MayFailRule;
/**
* Test for {@link Multiswarm}.
*
* @author Donato Rimenti
*
*/
public class MultiswarmUnitTest {
/**
* Rule for handling expected failures. We use this since this test may
* actually fail due to bad luck in the random generation.
*/
@Rule
public MayFailRule mayFailRule = new MayFailRule();
/**
* Tests the multiswarm algorithm with a generic problem. The problem is the
* following: <br>
* <br>
* In League of Legends, a player's Effective Health when defending against
* physical damage is given by E=H(100+A)/100, where H is health and A is
* armor. Health costs 2.5 gold per unit, and Armor costs 18 gold per unit.
* You have 3600 gold, and you need to optimize the effectiveness E of your
* health and armor to survive as long as possible against the enemy team's
* attacks. How much of each should you buy? <br>
* <br>
* The solution is H = 1080, A = 50 for a total fitness of 1620. Tested with
* 50 swarms each with 1000 particles.
*/
@Test
public void givenMultiswarm_whenThousandIteration_thenSolutionFound() {
Multiswarm multiswarm = new Multiswarm(50, 1000, new LolFitnessFunction());
// Iterates 1000 times through the main loop and prints the result.
for (int i = 0; i < 1000; i++) {
multiswarm.mainLoop();
}
System.out.println("Best fitness found: " + multiswarm.getBestFitness() + "[" + multiswarm.getBestPosition()[0]
+ "," + multiswarm.getBestPosition()[1] + "]");
Assert.assertEquals(1080, multiswarm.getBestPosition()[0]);
Assert.assertEquals(50, multiswarm.getBestPosition()[1]);
Assert.assertEquals(1620, (int) multiswarm.getBestFitness());
}
}

38
algorithms/src/test/java/com/baeldung/algorithms/support/MayFailRule.java Normal file
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package com.baeldung.algorithms.support;
import org.junit.Rule;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;
/**
* JUnit custom rule for managing tests that may fail due to heuristics or
* randomness. In order to use this, just instantiate this object as a public
* field inside the test class and annotate it with {@link Rule}.
*
* @author Donato Rimenti
*
*/
public class MayFailRule implements TestRule {
/*
* (non-Javadoc)
*
* @see org.junit.rules.TestRule#apply(org.junit.runners.model.Statement,
* org.junit.runner.Description)
*/
@Override
public Statement apply(Statement base, Description description) {
return new Statement() {
@Override
public void evaluate() throws Throwable {
try {
base.evaluate();
} catch (Throwable e) {
// Ignore the exception since we expect this.
}
}
};
}
}

76
apache-curator/pom.xml Normal file
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<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>apache-curator</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<parent>
<groupId>com.baeldung</groupId>
<artifactId>parent-modules</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<properties>
<curator.version>4.0.1</curator.version>
<zookeeper.version>3.4.11</zookeeper.version>
<jackson-databind.version>2.9.4</jackson-databind.version>
<!-- testing -->
<assertj.version>3.6.1</assertj.version>
<avaitility.version>1.7.0</avaitility.version>
</properties>
<dependencies>
<!-- curator -->
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-x-async</artifactId>
<version>${curator.version}</version>
<exclusions>
<exclusion>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
</exclusion>
</exclusions>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>${curator.version}</version>
</dependency>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>${zookeeper.version}</version>
</dependency>
<!-- utils -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson-databind.version}</version>
</dependency>
<!-- test scoped -->
<dependency>
<groupId>org.assertj</groupId>
<artifactId>assertj-core</artifactId>
<version>${assertj.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.jayway.awaitility</groupId>
<artifactId>awaitility</artifactId>
<version>${avaitility.version}</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>

31
apache-curator/src/main/java/com/baeldung/apache/curator/modeled/HostConfig.java Normal file
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package com.baeldung.apache.curator.modeled;
public class HostConfig {
private String hostname;
private int port;
public HostConfig() {
}
public HostConfig(String hostname, int port) {
this.hostname = hostname;
this.port = port;
}
public int getPort() {
return port;
}
public void setPort(int port) {
this.port = port;
}
public String getHostname() {
return hostname;
}
public void setHostname(String hostname) {
this.hostname = hostname;
}
}

22
apache-curator/src/test/java/com/baeldung/apache/curator/BaseTest.java Normal file
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package com.baeldung.apache.curator;
import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.RetryNTimes;
import org.junit.Before;
public abstract class BaseTest {
@Before
public void setup() {
org.apache.log4j.BasicConfigurator.configure();
}
protected CuratorFramework newClient() {
int sleepMsBetweenRetries = 100;
int maxRetries = 3;
RetryPolicy retryPolicy = new RetryNTimes(maxRetries, sleepMsBetweenRetries);
return CuratorFrameworkFactory.newClient("127.0.0.1:2181", retryPolicy);
}
}

89
apache-curator/src/test/java/com/baeldung/apache/curator/configuration/ConfigurationManagementManualTest.java Normal file
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package com.baeldung.apache.curator.configuration;
import static com.jayway.awaitility.Awaitility.await;
import static org.assertj.core.api.Assertions.assertThat;
import java.util.ArrayList;
import java.util.List;
import java.util.UUID;
import java.util.concurrent.atomic.AtomicBoolean;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.x.async.AsyncCuratorFramework;
import org.junit.Test;
import com.baeldung.apache.curator.BaseTest;
public class ConfigurationManagementManualTest extends BaseTest {
private static final String KEY_FORMAT = "/%s";
@Test
public void givenPath_whenCreateKey_thenValueIsStored() throws Exception {
try (CuratorFramework client = newClient()) {
client.start();
AsyncCuratorFramework async = AsyncCuratorFramework.wrap(client);
String key = getKey();
String expected = "my_value";
// Create key nodes structure
client.create()
.forPath(key);
// Set data value for our key
async.setData()
.forPath(key, expected.getBytes());
// Get data value
AtomicBoolean isEquals = new AtomicBoolean();
async.getData()
.forPath(key)
.thenAccept(
data -> isEquals.set(new String(data).equals(expected)));
await().until(() -> assertThat(isEquals.get()).isTrue());
}
}
@Test
public void givenPath_whenWatchAKeyAndStoreAValue_thenWatcherIsTriggered()
throws Exception {
try (CuratorFramework client = newClient()) {
client.start();
AsyncCuratorFramework async = AsyncCuratorFramework.wrap(client);
String key = getKey();
String expected = "my_value";
// Create key structure
async.create()
.forPath(key);
List<String> changes = new ArrayList<>();
// Watch data value
async.watched()
.getData()
.forPath(key)
.event()
.thenAccept(watchedEvent -> {
try {
changes.add(new String(client.getData()
.forPath(watchedEvent.getPath())));
} catch (Exception e) {
// fail ...
}
});
// Set data value for our key
async.setData()
.forPath(key, expected.getBytes());
await().until(() -> assertThat(changes.size() > 0).isTrue());
}
}
private String getKey() {
return String.format(KEY_FORMAT, UUID.randomUUID()
.toString());
}
}

79
apache-curator/src/test/java/com/baeldung/apache/curator/connection/ConnectionManagementManualTest.java Normal file
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package com.baeldung.apache.curator.connection;
import static com.jayway.awaitility.Awaitility.await;
import static org.assertj.core.api.Assertions.assertThat;
import java.util.concurrent.atomic.AtomicBoolean;
import org.apache.curator.RetryPolicy;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.CuratorFrameworkFactory;
import org.apache.curator.retry.RetryNTimes;
import org.apache.curator.x.async.AsyncCuratorFramework;
import org.junit.Test;
public class ConnectionManagementManualTest {
@Test
public void givenRunningZookeeper_whenOpenConnection_thenClientIsOpened()
throws Exception {
int sleepMsBetweenRetries = 100;
int maxRetries = 3;
RetryPolicy retryPolicy = new RetryNTimes(maxRetries,
sleepMsBetweenRetries);
try (CuratorFramework client = CuratorFrameworkFactory
.newClient("127.0.0.1:2181", retryPolicy)) {
client.start();
assertThat(client.checkExists()
.forPath("/")).isNotNull();
}
}
@Test
public void givenRunningZookeeper_whenOpenConnectionUsingAsyncNotBlocking_thenClientIsOpened()
throws InterruptedException {
int sleepMsBetweenRetries = 100;
int maxRetries = 3;
RetryPolicy retryPolicy = new RetryNTimes(maxRetries,
sleepMsBetweenRetries);
try (CuratorFramework client = CuratorFrameworkFactory
.newClient("127.0.0.1:2181", retryPolicy)) {
client.start();
AsyncCuratorFramework async = AsyncCuratorFramework.wrap(client);
AtomicBoolean exists = new AtomicBoolean(false);
async.checkExists()
.forPath("/")
.thenAcceptAsync(s -> exists.set(s != null));
await().until(() -> assertThat(exists.get()).isTrue());
}
}
@Test
public void givenRunningZookeeper_whenOpenConnectionUsingAsyncBlocking_thenClientIsOpened()
throws InterruptedException {
int sleepMsBetweenRetries = 100;
int maxRetries = 3;
RetryPolicy retryPolicy = new RetryNTimes(maxRetries,
sleepMsBetweenRetries);
try (CuratorFramework client = CuratorFrameworkFactory
.newClient("127.0.0.1:2181", retryPolicy)) {
client.start();
AsyncCuratorFramework async = AsyncCuratorFramework.wrap(client);
AtomicBoolean exists = new AtomicBoolean(false);
async.checkExists()
.forPath("/")
.thenAccept(s -> exists.set(s != null));
await().until(() -> assertThat(exists.get()).isTrue());
}
}
}

49
apache-curator/src/test/java/com/baeldung/apache/curator/modeled/ModelTypedExamplesManualTest.java Normal file
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package com.baeldung.apache.curator.modeled;
import static org.assertj.core.api.Assertions.assertThat;
import static org.assertj.core.api.Assertions.fail;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.x.async.AsyncCuratorFramework;
import org.apache.curator.x.async.modeled.JacksonModelSerializer;
import org.apache.curator.x.async.modeled.ModelSpec;
import org.apache.curator.x.async.modeled.ModeledFramework;
import org.apache.curator.x.async.modeled.ZPath;
import org.junit.Test;
import com.baeldung.apache.curator.BaseTest;
public class ModelTypedExamplesManualTest extends BaseTest {
@Test
public void givenPath_whenStoreAModel_thenNodesAreCreated()
throws InterruptedException {
ModelSpec<HostConfig> mySpec = ModelSpec
.builder(ZPath.parseWithIds("/config/dev"),
JacksonModelSerializer.build(HostConfig.class))
.build();
try (CuratorFramework client = newClient()) {
client.start();
AsyncCuratorFramework async = AsyncCuratorFramework.wrap(client);
ModeledFramework<HostConfig> modeledClient = ModeledFramework
.wrap(async, mySpec);
modeledClient.set(new HostConfig("host-name", 8080));
modeledClient.read()
.whenComplete((value, e) -> {
if (e != null) {
fail("Cannot read host config", e);
} else {
assertThat(value).isNotNull();
assertThat(value.getHostname()).isEqualTo("host-name");
assertThat(value.getPort()).isEqualTo(8080);
}
});
}
}
}

74
apache-curator/src/test/java/com/baeldung/apache/curator/recipes/RecipesManualTest.java Normal file
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package com.baeldung.apache.curator.recipes;
import static org.assertj.core.api.Assertions.assertThat;
import org.apache.curator.framework.CuratorFramework;
import org.apache.curator.framework.recipes.leader.LeaderSelector;
import org.apache.curator.framework.recipes.leader.LeaderSelectorListener;
import org.apache.curator.framework.recipes.locks.InterProcessSemaphoreMutex;
import org.apache.curator.framework.recipes.shared.SharedCount;
import org.apache.curator.framework.state.ConnectionState;
import org.junit.Test;
import com.baeldung.apache.curator.BaseTest;
public class RecipesManualTest extends BaseTest {
@Test
public void givenRunningZookeeper_whenUsingLeaderElection_thenNoErrors() {
try (CuratorFramework client = newClient()) {
client.start();
LeaderSelector leaderSelector = new LeaderSelector(client, "/mutex/select/leader/for/job/A", new LeaderSelectorListener() {
@Override
public void stateChanged(CuratorFramework client, ConnectionState newState) {
}
@Override
public void takeLeadership(CuratorFramework client) throws Exception {
// I'm the leader of the job A !
}
});
leaderSelector.start();
// Wait until the job A is done among all the members
leaderSelector.close();
}
}
@Test
public void givenRunningZookeeper_whenUsingSharedLock_thenNoErrors() throws Exception {
try (CuratorFramework client = newClient()) {
client.start();
InterProcessSemaphoreMutex sharedLock = new InterProcessSemaphoreMutex(client, "/mutex/process/A");
sharedLock.acquire();
// Do process A
sharedLock.release();
}
}
@Test
public void givenRunningZookeeper_whenUsingSharedCounter_thenCounterIsIncrement() throws Exception {
try (CuratorFramework client = newClient()) {
client.start();
try (SharedCount counter = new SharedCount(client, "/counters/A", 0)) {
counter.start();
counter.setCount(0);
counter.setCount(counter.getCount() + 1);
assertThat(counter.getCount()).isEqualTo(1);
}
}
}
}

1
apache-poi/README.md
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@ -1,3 +1,4 @@
### Relevant Articles:
- [Microsoft Word Processing in Java with Apache POI](http://www.baeldung.com/java-microsoft-word-with-apache-poi)
- [Working with Microsoft Excel in Java](http://www.baeldung.com/java-microsoft-excel)
- [Creating a MS PowerPoint Presentation in Java](https://github.com/eugenp/tutorials/tree/master/apache-poi)

36
apache-zookeeper/pom.xml Normal file
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<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>apache-zookeeper</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<parent>
<groupId>com.baeldung</groupId>
<artifactId>parent-modules</artifactId>
<version>1.0.0-SNAPSHOT</version>
</parent>
<dependencies>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.3.2</version>
<exclusions>
<exclusion>
<groupId>com.sun.jmx</groupId>
<artifactId>jmxri</artifactId>
</exclusion>
<exclusion>
<groupId>com.sun.jdmk</groupId>
<artifactId>jmxtools</artifactId>
</exclusion>
<exclusion>
<groupId>javax.jms</groupId>
<artifactId>jms</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
</project>

33
apache-zookeeper/src/main/java/com/baeldung/zookeeper/connection/ZKConnection.java Normal file
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package com.baeldung.zookeeper.connection;
import java.io.IOException;
import java.util.concurrent.CountDownLatch;
import org.apache.zookeeper.WatchedEvent;
import org.apache.zookeeper.Watcher;
import org.apache.zookeeper.Watcher.Event.KeeperState;
import org.apache.zookeeper.ZooKeeper;
public class ZKConnection {
private ZooKeeper zoo;
final CountDownLatch connectionLatch = new CountDownLatch(1);
public ZKConnection() {
}
public ZooKeeper connect(String host) throws IOException, InterruptedException {
zoo = new ZooKeeper(host, 2000, new Watcher() {
public void process(WatchedEvent we) {
if (we.getState() == KeeperState.SyncConnected) {
connectionLatch.countDown();
}
}
});
connectionLatch.await();
return zoo;
}
public void close() throws InterruptedException {
zoo.close();
}
}

35
apache-zookeeper/src/main/java/com/baeldung/zookeeper/manager/ZKManager.java Normal file
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package com.baeldung.zookeeper.manager;
import org.apache.zookeeper.KeeperException;
public interface ZKManager {
/**
* Create a Znode and save some data
*
* @param path
* @param data
* @throws KeeperException
* @throws InterruptedException
*/
public void create(String path, byte[] data) throws KeeperException, InterruptedException;
/**
* Get ZNode Data
*
* @param path
* @param boolean watchFlag
* @throws KeeperException
* @throws InterruptedException
*/
public Object getZNodeData(String path, boolean watchFlag);
/**
* Update the ZNode Data
*
* @param path
* @param data
* @throws KeeperException
* @throws InterruptedException
*/
public void update(String path, byte[] data) throws KeeperException, InterruptedException, KeeperException;
}

58
apache-zookeeper/src/main/java/com/baeldung/zookeeper/manager/ZKManagerImpl.java Normal file
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package com.baeldung.zookeeper.manager;
import org.apache.zookeeper.CreateMode;
import org.apache.zookeeper.KeeperException;
import org.apache.zookeeper.ZooDefs;
import org.apache.zookeeper.ZooKeeper;
import com.baeldung.zookeeper.connection.ZKConnection;
public class ZKManagerImpl implements ZKManager {
private static ZooKeeper zkeeper;
private static ZKConnection zkConnection;
public ZKManagerImpl() {
initialize();
}
/** * Initialize connection */
private void initialize() {
try {
zkConnection = new ZKConnection();
zkeeper = zkConnection.connect("localhost");
} catch (Exception e) {
System.out.println(e.getMessage());
}
}
public void closeConnection() {
try {
zkConnection.close();
} catch (InterruptedException e) {
System.out.println(e.getMessage());
}
}
public void create(String path, byte[] data) throws KeeperException, InterruptedException {
zkeeper.create(path, data, ZooDefs.Ids.OPEN_ACL_UNSAFE, CreateMode.PERSISTENT);
}
public Object getZNodeData(String path, boolean watchFlag) {
try {
byte[] b = null;
b = zkeeper.getData(path, null, null);
String data = new String(b, "UTF-8");
System.out.println(data);
return data;
} catch (Exception e) {
System.out.println(e.getMessage());
}
return null;
}
public void update(String path, byte[] data) throws KeeperException, InterruptedException {
int version = zkeeper.exists(path, true)
.getVersion();
zkeeper.setData(path, data, version);
}
}

137
aws/src/main/java/com/baeldung/ec2/EC2Application.java Normal file
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package com.baeldung.ec2;
import java.util.Arrays;
import com.amazonaws.auth.AWSCredentials;
import com.amazonaws.auth.AWSStaticCredentialsProvider;
import com.amazonaws.auth.BasicAWSCredentials;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.ec2.AmazonEC2;
import com.amazonaws.services.ec2.AmazonEC2ClientBuilder;
import com.amazonaws.services.ec2.model.AuthorizeSecurityGroupIngressRequest;
import com.amazonaws.services.ec2.model.CreateKeyPairRequest;
import com.amazonaws.services.ec2.model.CreateKeyPairResult;
import com.amazonaws.services.ec2.model.CreateSecurityGroupRequest;
import com.amazonaws.services.ec2.model.DescribeInstancesRequest;
import com.amazonaws.services.ec2.model.DescribeInstancesResult;
import com.amazonaws.services.ec2.model.DescribeKeyPairsRequest;
import com.amazonaws.services.ec2.model.DescribeKeyPairsResult;
import com.amazonaws.services.ec2.model.IpPermission;
import com.amazonaws.services.ec2.model.IpRange;
import com.amazonaws.services.ec2.model.MonitorInstancesRequest;
import com.amazonaws.services.ec2.model.RebootInstancesRequest;
import com.amazonaws.services.ec2.model.RunInstancesRequest;
import com.amazonaws.services.ec2.model.StartInstancesRequest;
import com.amazonaws.services.ec2.model.StopInstancesRequest;
import com.amazonaws.services.ec2.model.UnmonitorInstancesRequest;
public class EC2Application {
private static final AWSCredentials credentials;
static {
// put your accesskey and secretkey here
credentials = new BasicAWSCredentials(
"<AWS accesskey>",
"<AWS secretkey>"
);
}
public static void main(String[] args) {
// Set up the client
AmazonEC2 ec2Client = AmazonEC2ClientBuilder.standard()
.withCredentials(new AWSStaticCredentialsProvider(credentials))
.withRegion(Regions.US_EAST_1)
.build();
// Create a security group
CreateSecurityGroupRequest createSecurityGroupRequest = new CreateSecurityGroupRequest().withGroupName("BaeldungSecurityGroup")
.withDescription("Baeldung Security Group");
ec2Client.createSecurityGroup(createSecurityGroupRequest);
// Allow HTTP and SSH traffic
IpRange ipRange1 = new IpRange().withCidrIp("0.0.0.0/0");
IpPermission ipPermission1 = new IpPermission().withIpv4Ranges(Arrays.asList(new IpRange[] { ipRange1 }))
.withIpProtocol("tcp")
.withFromPort(80)
.withToPort(80);
IpPermission ipPermission2 = new IpPermission().withIpv4Ranges(Arrays.asList(new IpRange[] { ipRange1 }))
.withIpProtocol("tcp")
.withFromPort(22)
.withToPort(22);
AuthorizeSecurityGroupIngressRequest authorizeSecurityGroupIngressRequest = new AuthorizeSecurityGroupIngressRequest()
.withGroupName("BaeldungSecurityGroup")
.withIpPermissions(ipPermission1, ipPermission2);
ec2Client.authorizeSecurityGroupIngress(authorizeSecurityGroupIngressRequest);
// Create KeyPair
CreateKeyPairRequest createKeyPairRequest = new CreateKeyPairRequest()
.withKeyName("baeldung-key-pair");
CreateKeyPairResult createKeyPairResult = ec2Client.createKeyPair(createKeyPairRequest);
String privateKey = createKeyPairResult
.getKeyPair()
.getKeyMaterial(); // make sure you keep it, the private key, Amazon doesn't store the private key
// See what key-pairs you've got
DescribeKeyPairsRequest describeKeyPairsRequest = new DescribeKeyPairsRequest();
DescribeKeyPairsResult describeKeyPairsResult = ec2Client.describeKeyPairs(describeKeyPairsRequest);
// Launch an Amazon Instance
RunInstancesRequest runInstancesRequest = new RunInstancesRequest().withImageId("ami-97785bed") // https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AMIs.html | https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/usingsharedamis-finding.html
.withInstanceType("t2.micro") // https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-types.html
.withMinCount(1)
.withMaxCount(1)
.withKeyName("baeldung-key-pair") // optional - if not present, can't connect to instance
.withSecurityGroups("BaeldungSecurityGroup");
String yourInstanceId = ec2Client.runInstances(runInstancesRequest).getReservation().getInstances().get(0).getInstanceId();
// Start an Instance
StartInstancesRequest startInstancesRequest = new StartInstancesRequest()
.withInstanceIds(yourInstanceId);
ec2Client.startInstances(startInstancesRequest);
// Monitor Instances
MonitorInstancesRequest monitorInstancesRequest = new MonitorInstancesRequest()
.withInstanceIds(yourInstanceId);
ec2Client.monitorInstances(monitorInstancesRequest);
UnmonitorInstancesRequest unmonitorInstancesRequest = new UnmonitorInstancesRequest()
.withInstanceIds(yourInstanceId);
ec2Client.unmonitorInstances(unmonitorInstancesRequest);
// Reboot an Instance
RebootInstancesRequest rebootInstancesRequest = new RebootInstancesRequest()
.withInstanceIds(yourInstanceId);
ec2Client.rebootInstances(rebootInstancesRequest);
// Stop an Instance
StopInstancesRequest stopInstancesRequest = new StopInstancesRequest()
.withInstanceIds(yourInstanceId);
ec2Client.stopInstances(stopInstancesRequest)
.getStoppingInstances()
.get(0)
.getPreviousState()
.getName();
// Describe an Instance
DescribeInstancesRequest describeInstancesRequest = new DescribeInstancesRequest();
DescribeInstancesResult response = ec2Client.describeInstances(describeInstancesRequest);
System.out.println(response.getReservations()
.get(0)
.getInstances()
.get(0)
.getKernelId());
}
}

114
checker-plugin/pom.xml Normal file
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<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.baeldung</groupId>
<artifactId>checker-plugin</artifactId>
<packaging>jar</packaging>
<version>1.0-SNAPSHOT</version>
<name>checker-plugin</name>
<url>http://maven.apache.org</url>
<!-- https://checkerframework.org/manual/#maven -->
<properties>
<!-- These properties will be set by the Maven Dependency plugin -->
<annotatedJdk>${org.checkerframework:jdk8:jar}</annotatedJdk>
<!-- Uncomment to use the Type Annotations compiler. -->
<!--
<typeAnnotationsJavac>${org.checkerframework:compiler:jar}</typeAnnotationsJavac>
-->
</properties>
<dependencies>
<!-- Annotations from the Checker Framework: nullness, interning, locking, ... -->
<dependency>
<groupId>org.checkerframework</groupId>
<artifactId>checker-qual</artifactId>
<version>2.3.1</version>
</dependency>
<dependency>
<groupId>org.checkerframework</groupId>
<artifactId>checker</artifactId>
<version>2.3.1</version>
</dependency>
<dependency>
<groupId>org.checkerframework</groupId>
<artifactId>jdk8</artifactId>
<version>2.3.1</version>
</dependency>
<!-- The Type Annotations compiler. Uncomment if using annotations in comments. -->
<dependency>
<groupId>org.checkerframework</groupId>
<artifactId>compiler</artifactId>
<version>2.3.1</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<!-- This plugin will set properties values using dependency information -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<goals>
<!--
Goal that sets a property pointing to the artifact file for each project dependency.
For each dependency (direct and transitive) a project property will be set which
follows the:
groupId:artifactId:type:[classifier]
form and contains the path to the resolved artifact. -->
<goal>properties</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.6.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<!-- Uncomment the following line to use the type annotations compiler. -->
<!-- <fork>true</fork> -->
<compilerArguments>
<Xmaxerrs>10000</Xmaxerrs>
<Xmaxwarns>10000</Xmaxwarns>
</compilerArguments>
<annotationProcessors>
<!-- Add all the checkers you want to enable here -->
<annotationProcessor>org.checkerframework.checker.nullness.NullnessChecker</annotationProcessor>
<annotationProcessor>org.checkerframework.checker.interning.InterningChecker</annotationProcessor>
<annotationProcessor>org.checkerframework.checker.fenum.FenumChecker</annotationProcessor>
<annotationProcessor>org.checkerframework.checker.formatter.FormatterChecker</annotationProcessor>
<annotationProcessor>org.checkerframework.checker.regex.RegexChecker</annotationProcessor>
</annotationProcessors>
<compilerArgs>
<arg>-AprintErrorStack</arg>
<!-- location of the annotated JDK, which comes from a Maven dependency -->
<arg>-Xbootclasspath/p:${annotatedJdk}</arg>
<!--
-->
<!-- Uncomment the following line to use the type annotations compiler. -->
<!--
<arg>-J-Xbootclasspath/p:${typeAnnotationsJavac}</arg>
-->
<!-- Uncomment the following line to turn type-checking warnings into errors. -->
<arg>-Awarns</arg>
</compilerArgs>
</configuration>
</plugin>
</plugins>
</build>
</project>

42
checker-plugin/src/main/java/com/baeldung/typechecker/FakeNumExample.java Normal file
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package com.baeldung.typechecker;
import org.checkerframework.checker.fenum.qual.Fenum;
//@SuppressWarnings("fenum:assignment.type.incompatible")
public class FakeNumExample {
// Here we use some String constants to represents countries.
static final @Fenum("country") String ITALY = "IT";
static final @Fenum("country") String US = "US";
static final @Fenum("country") String UNITED_KINGDOM = "UK";
// Here we use other String constants to represent planets instead.
static final @Fenum("planet") String MARS = "Mars";
static final @Fenum("planet") String EARTH = "Earth";
static final @Fenum("planet") String VENUS = "Venus";
// Now we write this method and we want to be sure that
// the String parameter has a value of a country, not that is just a String.
void greetCountries(@Fenum("country") String country) {
System.out.println("Hello " + country);
}
// Similarly we're enforcing here that the provided
// parameter is a String that represent a planet.
void greetPlanets(@Fenum("planet") String planet) {
System.out.println("Hello " + planet);
}
public static void main(String[] args) {
FakeNumExample obj = new FakeNumExample();
// This will fail because we pass a planet-String to a method that
// accept a country-String.
obj.greetCountries(MARS);
// Here the opposite happens.
obj.greetPlanets(US);
}
}

23
checker-plugin/src/main/java/com/baeldung/typechecker/FormatExample.java Normal file
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package com.baeldung.typechecker;
public class FormatExample {
public static void main(String[] args) {
// Just enabling org.checkerframework.checker.formatter.FormatterChecker
// we can be sure at compile time that the format strings we pass to format()
// are correct. Normally we would have those errors raised just at runtime.
// All those formats are in fact wrong.
String.format("%y", 7); // error: invalid format string
String.format("%d", "a string"); // error: invalid argument type for %d
String.format("%d %s", 7); // error: missing argument for %s
String.format("%d", 7, 3); // warning: unused argument 3
String.format("{0}", 7); // warning: unused argument 7, because {0} is wrong syntax
}
}

31
checker-plugin/src/main/java/com/baeldung/typechecker/KeyForExample.java Normal file
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package com.baeldung.typechecker;
import org.checkerframework.checker.nullness.qual.KeyFor;
import java.util.HashMap;
import java.util.Map;
public class KeyForExample {
private final Map<String, String> config = new HashMap<>();
KeyForExample() {
// Here we initialize a map to store
// some config data.
config.put("url", "http://1.2.3.4");
config.put("name", "foobaz");
}
public void dumpPort() {
// Here, we want to dump the port value stored in the
// config, so we declare that this key has to be
// present in the config map.
// Obviously that will fail because such key is not present
// in the map.
@KeyFor("config") String key = "port";
System.out.println( config.get(key) );
}
}

28
checker-plugin/src/main/java/com/baeldung/typechecker/MonotonicNotNullExample.java Normal file
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package com.baeldung.typechecker;
import org.checkerframework.checker.nullness.qual.MonotonicNonNull;
import java.util.Date;
public class MonotonicNotNullExample {
// The idea is we need this field to be to lazily initialized,
// so it starts as null but once it becomes not null
// it cannot return null.
// In these cases, we can use @MonotonicNonNull
@MonotonicNonNull private Date firstCall;
public Date getFirstCall() {
if (firstCall == null) {
firstCall = new Date();
}
return firstCall;
}
public void reset() {
// This is reported as error because
// we wrongly set the field back to null.
firstCall = null;
}
}

27
checker-plugin/src/main/java/com/baeldung/typechecker/NonNullExample.java Normal file
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package com.baeldung.typechecker;
import org.checkerframework.checker.nullness.qual.NonNull;
import org.checkerframework.checker.nullness.qual.Nullable;
public class NonNullExample {
// This method's parameter is annotated in order
// to tell the pluggable type system that it can never be null.
private static int countArgs(@NonNull String[] args) {
return args.length;
}
// This method's parameter is annotated in order
// to tell the pluggable type system that it may be null.
public static void main(@Nullable String[] args) {
// Here lies a potential error,
// because we pass a potential null reference to a method
// that does not accept nulls.
// The Checker Framework will spot this problem at compile time
// instead of runtime.
System.out.println(countArgs(args));
}
}

18
checker-plugin/src/main/java/com/baeldung/typechecker/RegexExample.java Normal file
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package com.baeldung.typechecker;
import org.checkerframework.checker.regex.qual.Regex;
public class RegexExample {
// For some reason we want to be sure that this regex
// contains at least one capturing group.
// However, we do an error and we forgot to define such
// capturing group in it.
@Regex(1) private static String findNumbers = "\\d*";
public static void main(String[] args) {
String message = "My phone number is +3911223344.";
message.matches(findNumbers);
}
}

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core-groovy/README.md Normal file
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# Groovy
## Relevant articles:

13
core-groovy/build.gradle Normal file
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group 'com.baeldung'
version '1.0-SNAPSHOT'
apply plugin: 'groovy'
repositories {
mavenCentral()
}
dependencies {
compile 'org.codehaus.groovy:groovy-all:2.4.13'
testCompile 'org.spockframework:spock-core:1.1-groovy-2.4'
}

128
core-groovy/pom.xml Normal file
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<?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>core-groovy</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>
<repositories>
<repository>
<id>central</id>
<url>http://jcenter.bintray.com</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy</artifactId>
<version>2.4.13</version>
</dependency>
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-all</artifactId>
<version>2.4.13</version>
</dependency>
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-sql</artifactId>
<version>2.4.13</version>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-engine</artifactId>
<version>${junit.jupiter.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.platform</groupId>
<artifactId>junit-platform-runner</artifactId>
<version>${junit.platform.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<version>2.4.0</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.spockframework</groupId>
<artifactId>spock-core</artifactId>
<version>1.1-groovy-2.4</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.codehaus.gmavenplus</groupId>
<artifactId>gmavenplus-plugin</artifactId>
<version>1.6</version>
<executions>
<execution>
<goals>
<goal>addSources</goal>
<goal>addTestSources</goal>
<goal>compile</goal>
<goal>compileTests</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>${maven-surefire-plugin.version}</version>
</plugin>
<plugin>
<artifactId>maven-failsafe-plugin</artifactId>
<version>2.19.1</version>
<dependencies>
<dependency>
<groupId>org.junit.platform</groupId>
<artifactId>junit-platform-surefire-provider</artifactId>
<version>${junit.platform.version}</version>
</dependency>
</dependencies>
<executions>
<execution>
<id>junit5</id>
<goals>
<goal>integration-test</goal>
<goal>verify</goal>
</goals>
<configuration>
<includes>
<include>**/*Test5.java</include>
</includes>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<kotlin-maven-plugin.version>1.1.2</kotlin-maven-plugin.version>
<kotlin-test-junit.version>1.1.2</kotlin-test-junit.version>
<kotlin-stdlib.version>1.1.2</kotlin-stdlib.version>
<kotlin-reflect.version>1.1.2</kotlin-reflect.version>
<kotlinx.version>0.15</kotlinx.version>
<mockito-kotlin.version>1.5.0</mockito-kotlin.version>
<junit.jupiter.version>5.0.0</junit.jupiter.version>
<junit.platform.version>1.0.0</junit.platform.version>
<junit.vintage.version>4.12.0</junit.vintage.version>
<junit4.version>4.12</junit4.version>
</properties>
</project>

7
core-groovy/src/main/groovy/com/baeldung/json/Account.groovy Normal file
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package com.baeldung.json
class Account {
String id
BigDecimal value
Date createdAt
}

27
core-groovy/src/main/groovy/com/baeldung/json/JsonParser.groovy Normal file
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package com.baeldung.json
import groovy.json.JsonOutput
import groovy.json.JsonParserType
import groovy.json.JsonSlurper
class JsonParser {
Account toObject(String json) {
JsonSlurper jsonSlurper = new JsonSlurper()
jsonSlurper.parseText(json) as Account
}
Account toObjectWithIndexOverlay(String json) {
JsonSlurper jsonSlurper = new JsonSlurper(type: JsonParserType.INDEX_OVERLAY)
jsonSlurper.parseText(json) as Account
}
String toJson(Account account) {
JsonOutput.toJson(account)
}
String prettyfy(String json) {
JsonOutput.prettyPrint(json)
}
}

229
core-groovy/src/test/groovy/com/baeldung/groovy/sql/SqlTest.groovy Normal file
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package com.baeldung.groovy.sql
import groovy.sql.GroovyResultSet
import groovy.sql.GroovyRowResult
import groovy.sql.Sql
import groovy.transform.CompileStatic
import static org.junit.Assert.*
import org.junit.Test
class SqlTest {
final Map dbConnParams = [url: 'jdbc:hsqldb:mem:testDB', user: 'sa', password: '', driver: 'org.hsqldb.jdbc.JDBCDriver']
@Test
void whenNewSqlInstance_thenDbIsAccessed() {
def sql = Sql.newInstance(dbConnParams)
sql.close()
sql.close()
}
@Test
void whenTableDoesNotExist_thenSelectFails() {
try {
Sql.withInstance(dbConnParams) { Sql sql ->
sql.eachRow('select * from PROJECT') {}
}
fail("An exception should have been thrown")
} catch (ignored) {
//Ok
}
}
@Test
void whenTableCreated_thenSelectIsPossible() {
Sql.withInstance(dbConnParams) { Sql sql ->
def result = sql.execute 'create table PROJECT_1 (id integer not null, name varchar(50), url varchar(100))'
assertEquals(0, sql.updateCount)
assertFalse(result)
result = sql.execute('select * from PROJECT_1')
assertTrue(result)
}
}
@Test
void whenIdentityColumn_thenInsertReturnsNewId() {
Sql.withInstance(dbConnParams) { Sql sql ->
sql.execute 'create table PROJECT_2 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
def ids = sql.executeInsert("INSERT INTO PROJECT_2 (NAME, URL) VALUES ('tutorials', 'github.com/eugenp/tutorials')")
assertEquals(0, ids[0][0])
ids = sql.executeInsert("INSERT INTO PROJECT_2 (NAME, URL) VALUES ('REST with Spring', 'github.com/eugenp/REST-With-Spring')")
assertEquals(1, ids[0][0])
}
}
@Test
void whenUpdate_thenNumberOfAffectedRows() {
Sql.withInstance(dbConnParams) { Sql sql ->
sql.execute 'create table PROJECT_3 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
sql.executeInsert("INSERT INTO PROJECT_3 (NAME, URL) VALUES ('tutorials', 'github.com/eugenp/tutorials')")
sql.executeInsert("INSERT INTO PROJECT_3 (NAME, URL) VALUES ('REST with Spring', 'github.com/eugenp/REST-With-Spring')")
def count = sql.executeUpdate("UPDATE PROJECT_3 SET URL = 'https://' + URL")
assertEquals(2, count)
}
}
@Test
void whenEachRow_thenResultSetHasProperties() {
Sql.withInstance(dbConnParams) { Sql sql ->
sql.execute 'create table PROJECT_4 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
sql.executeInsert("INSERT INTO PROJECT_4 (NAME, URL) VALUES ('tutorials', 'https://github.com/eugenp/tutorials')")
sql.executeInsert("INSERT INTO PROJECT_4 (NAME, URL) VALUES ('REST with Spring', 'https://github.com/eugenp/REST-With-Spring')")
sql.eachRow("SELECT * FROM PROJECT_4") { GroovyResultSet rs ->
assertNotNull(rs.name)
assertNotNull(rs.url)
assertNotNull(rs[0])
assertNotNull(rs[1])
assertNotNull(rs[2])
assertEquals(rs.name, rs['name'])
assertEquals(rs.url, rs['url'])
}
}
}
@Test
void whenPagination_thenSubsetIsReturned() {
Sql.withInstance(dbConnParams) { Sql sql ->
sql.execute 'create table PROJECT_5 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
sql.executeInsert("INSERT INTO PROJECT_5 (NAME, URL) VALUES ('tutorials', 'github.com/eugenp/tutorials')")
sql.executeInsert("INSERT INTO PROJECT_5 (NAME, URL) VALUES ('REST with Spring', 'github.com/eugenp/REST-With-Spring')")
def rows = sql.rows('SELECT * FROM PROJECT_5 ORDER BY NAME', 1, 1)
assertEquals(1, rows.size())
assertEquals('REST with Spring', rows[0].name)
}
}
@Test
void whenParameters_thenReplacement() {
Sql.withInstance(dbConnParams) { Sql sql ->
sql.execute 'create table PROJECT_6 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
sql.execute('INSERT INTO PROJECT_6 (NAME, URL) VALUES (?, ?)', 'tutorials', 'github.com/eugenp/tutorials')
sql.execute("INSERT INTO PROJECT_6 (NAME, URL) VALUES (:name, :url)", [name: 'REST with Spring', url: 'github.com/eugenp/REST-With-Spring'])
def rows = sql.rows("SELECT * FROM PROJECT_6 WHERE NAME = 'tutorials'")
assertEquals(1, rows.size())
rows = sql.rows("SELECT * FROM PROJECT_6 WHERE NAME = 'REST with Spring'")
assertEquals(1, rows.size())
}
}
@Test
void whenParametersInGString_thenReplacement() {
Sql.withInstance(dbConnParams) { Sql sql ->
sql.execute 'create table PROJECT_7 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
sql.execute "INSERT INTO PROJECT_7 (NAME, URL) VALUES (${'tutorials'}, ${'github.com/eugenp/tutorials'})"
def name = 'REST with Spring'
def url = 'github.com/eugenp/REST-With-Spring'
sql.execute "INSERT INTO PROJECT_7 (NAME, URL) VALUES (${name}, ${url})"
def rows = sql.rows("SELECT * FROM PROJECT_7 WHERE NAME = 'tutorials'")
assertEquals(1, rows.size())
rows = sql.rows("SELECT * FROM PROJECT_7 WHERE NAME = 'REST with Spring'")
assertEquals(1, rows.size())
}
}
@Test
void whenTransactionRollback_thenNoDataInserted() {
Sql.withInstance(dbConnParams) { Sql sql ->
sql.withTransaction {
sql.execute 'create table PROJECT_8 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
sql.executeInsert("INSERT INTO PROJECT_8 (NAME, URL) VALUES ('tutorials', 'https://github.com/eugenp/tutorials')")
sql.executeInsert("INSERT INTO PROJECT_8 (NAME, URL) VALUES ('REST with Spring', 'https://github.com/eugenp/REST-With-Spring')")
sql.rollback()
def rows = sql.rows("SELECT * FROM PROJECT_8")
assertEquals(0, rows.size())
}
}
}
@Test
void whenTransactionRollbackThenCommit_thenOnlyLastInserted() {
Sql.withInstance(dbConnParams) { Sql sql ->
sql.withTransaction {
sql.execute 'create table PROJECT_9 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
sql.executeInsert("INSERT INTO PROJECT_9 (NAME, URL) VALUES ('tutorials', 'https://github.com/eugenp/tutorials')")
sql.rollback()
sql.executeInsert("INSERT INTO PROJECT_9 (NAME, URL) VALUES ('REST with Spring', 'https://github.com/eugenp/REST-With-Spring')")
sql.rollback()
sql.executeInsert("INSERT INTO PROJECT_9 (NAME, URL) VALUES ('tutorials', 'https://github.com/eugenp/tutorials')")
sql.executeInsert("INSERT INTO PROJECT_9 (NAME, URL) VALUES ('REST with Spring', 'https://github.com/eugenp/REST-With-Spring')")
}
def rows = sql.rows("SELECT * FROM PROJECT_9")
assertEquals(2, rows.size())
}
}
@Test
void whenException_thenTransactionIsRolledBack() {
Sql.withInstance(dbConnParams) { Sql sql ->
try {
sql.withTransaction {
sql.execute 'create table PROJECT_10 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
sql.executeInsert("INSERT INTO PROJECT_10 (NAME, URL) VALUES ('tutorials', 'https://github.com/eugenp/tutorials')")
throw new Exception('rollback')
}
} catch (ignored) {}
def rows = sql.rows("SELECT * FROM PROJECT_10")
assertEquals(0, rows.size())
}
}
@Test
void givenCachedConnection_whenException_thenDataIsPersisted() {
Sql.withInstance(dbConnParams) { Sql sql ->
try {
sql.cacheConnection {
sql.execute 'create table PROJECT_11 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
sql.executeInsert("INSERT INTO PROJECT_11 (NAME, URL) VALUES ('tutorials', 'https://github.com/eugenp/tutorials')")
throw new Exception('This does not rollback')
}
} catch (ignored) {}
def rows = sql.rows("SELECT * FROM PROJECT_11")
assertEquals(1, rows.size())
}
}
/*@Test
void whenModifyResultSet_thenDataIsChanged() {
Sql.withInstance(dbConnParams) { Sql sql ->
sql.execute 'create table PROJECT_5 (ID IDENTITY, NAME VARCHAR (50), URL VARCHAR (100))'
sql.executeInsert("INSERT INTO PROJECT_5 (NAME, URL) VALUES ('tutorials', 'github.com/eugenp/tutorials')")
sql.executeInsert("INSERT INTO PROJECT_5 (NAME, URL) VALUES ('REST with Spring', 'github.com/eugenp/REST-With-Spring')")
sql.eachRow("SELECT * FROM PROJECT_5 FOR UPDATE ") { GroovyResultSet rs ->
rs['name'] = "The great ${rs.name}!" as String
rs.updateRow()
}
sql.eachRow("SELECT * FROM PROJECT_5") { GroovyResultSet rs ->
assertTrue(rs.name.startsWith('The great '))
}
}
}*/
}

66
core-groovy/src/test/groovy/com/baeldung/json/JsonParserTest.groovy Normal file
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@ -0,0 +1,66 @@
package com.baeldung.json
import spock.lang.Specification
import java.text.SimpleDateFormat
class JsonParserTest extends Specification {
JsonParser jsonParser
void setup () {
jsonParser = new JsonParser()
}
def 'Should parse to Account given Json String' () {
given:
def json = '{"id":"1234","value":15.6}'
when:
def account = jsonParser.toObject(json)
then:
account
account instanceof Account
account.id == '1234'
account.value == 15.6
}
def 'Should parse to Account given Json String with date property' () {
given:
def json = '{"id":"1234","value":15.6,"createdAt":"2018-01-01T00:00:00+0000"}'
when:
def account = jsonParser.toObjectWithIndexOverlay(json)
then:
account
account instanceof Account
account.id == '1234'
account.value == 15.6
println account.createdAt
account.createdAt == Date.parse('yyyy-MM-dd', '2018-01-01')
}
def 'Should parse to Json given an Account object' () {
given:
Account account = new Account(
id: '123',
value: 15.6,
createdAt: new SimpleDateFormat('MM/dd/yyyy').parse('01/01/2018')
)
when:
def json = jsonParser.toJson(account)
then:
json
json == '{"value":15.6,"createdAt":"2018-01-01T00:00:00+0000","id":"123"}'
}
def 'Should prettify given a json string' () {
given:
String json = '{"value":15.6,"createdAt":"01/01/2018","id":"123456"}'
when:
def jsonPretty = jsonParser.prettyfy(json)
then:
jsonPretty
jsonPretty == '{\n "value": 15.6,\n "createdAt": "01/01/2018",\n "id": "123456"\n}'
}
}

6
core-java-8/README.md
View File

@ -37,3 +37,9 @@
- [Iterable to Stream in Java](http://www.baeldung.com/java-iterable-to-stream)
- [Converting String to Stream of chars](http://www.baeldung.com/java-string-to-stream)
- [How to Iterate Over a Stream With Indices](http://www.baeldung.com/java-stream-indices)
- [Efficient Word Frequency Calculator in Java](http://www.baeldung.com/java-word-frequency)
- [Primitive Type Streams in Java 8](http://www.baeldung.com/java-8-primitive-streams)
- [Fail-Safe Iterator vs Fail-Fast Iterator](http://www.baeldung.com/java-fail-safe-vs-fail-fast-iterator)
- [Shuffling Collections In Java](http://www.baeldung.com/java-shuffle-collection)
- [Java 8 StringJoiner](http://www.baeldung.com/java-string-joiner)
- [Introduction to Spliterator in Java](http://www.baeldung.com/java-spliterator)

44
core-java-8/src/main/java/com/baeldung/spliteratorAPI/Executor.java
View File

@ -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());
}
}
}

70
core-java-8/src/main/java/com/baeldung/spliteratorAPI/RelatedAuthorSpliterator.java
View File

@ -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;
}
}

9
core-java-8/src/main/java/com/baeldung/spliteratorAPI/Task.java
View File

@ -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;
}
}

70
core-java-8/src/test/java/com/baeldung/shufflingcollections/ShufflingCollectionsUnitTest.java Normal file
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@ -0,0 +1,70 @@
package com.baeldung.shufflingcollections;
import org.junit.Test;
import java.util.*;
import java.util.stream.Collectors;
import static org.assertj.core.api.Assertions.assertThat;
public class ShufflingCollectionsUnitTest {
@Test
public void whenShufflingList_thenListIsShuffled() {
List<String> students = Arrays.asList("Foo", "Bar", "Baz", "Qux");
System.out.println("List before shuffling:");
System.out.println(students);
Collections.shuffle(students);
System.out.println("List after shuffling:");
System.out.println(students);
}
@Test
public void whenShufflingMapEntries_thenValuesAreShuffled() {
Map<Integer, String> studentsById = new HashMap<>();
studentsById.put(1, "Foo");
studentsById.put(2, "Bar");
studentsById.put(3, "Baz");
studentsById.put(4, "Qux");
System.out.println("Students before shuffling:");
System.out.println(studentsById.values());
List<Map.Entry<Integer, String>> shuffledStudentEntries = new ArrayList<>(studentsById.entrySet());
Collections.shuffle(shuffledStudentEntries);
List<String> shuffledStudents = shuffledStudentEntries.stream()
.map(Map.Entry::getValue)
.collect(Collectors.toList());
System.out.println("Students after shuffling");
System.out.println(shuffledStudents);
}
@Test
public void whenShufflingSet_thenElementsAreShuffled() {
Set<String> students = new HashSet<>(Arrays.asList("Foo", "Bar", "Baz", "Qux"));
System.out.println("Set before shuffling:");
System.out.println(students);
List<String> studentList = new ArrayList<>(students);
Collections.shuffle(studentList);
System.out.println("Shuffled set elements:");
System.out.println(studentList);
}
@Test
public void whenShufflingWithSameRandomness_thenElementsAreShuffledDeterministically() {
List<String> students_1 = Arrays.asList("Foo", "Bar", "Baz", "Qux");
List<String> students_2 = Arrays.asList("Foo", "Bar", "Baz", "Qux");
Collections.shuffle(students_1, new Random(5));
Collections.shuffle(students_2, new Random(5));
assertThat(students_1).isEqualTo(students_2);
}
}

44
core-java-8/src/test/java/com/baeldung/spliteratorAPI/ExecutorTest.java Normal file
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@ -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 + "");
}
}

17
core-java-9/src/main/java/com/baeldung/java9/methodhandles/Book.java Normal file
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@ -0,0 +1,17 @@
package com.baeldung.java9.methodhandles;
public class Book {
String id;
String title;
public Book(String id, String title) {
this.id = id;
this.title = title;
}
@SuppressWarnings("unused")
private String formatBook() {
return id + " > " + title;
}
}

218
core-java-9/src/test/java/com/baeldung/java9/httpclient/HttpClientTest.java Normal file
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@ -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"));
}
}
}

171
core-java-9/src/test/java/com/baeldung/java9/httpclient/HttpRequestTest.java Normal file
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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"));
}
}

55
core-java-9/src/test/java/com/baeldung/java9/httpclient/HttpResponseTest.java Normal file
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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/"));
}
}

126
core-java-9/src/test/java/com/baeldung/java9/httpclient/SimpleHttpRequestsUnitTest.java
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@ -1,126 +0,0 @@
package com.baeldung.java9.httpclient;
import static java.net.HttpURLConnection.HTTP_OK;
import static org.junit.Assert.assertTrue;
import java.io.IOException;
import java.net.CookieManager;
import java.net.CookiePolicy;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.http.HttpClient;
import java.net.http.HttpHeaders;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;
import java.security.NoSuchAlgorithmException;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLParameters;
import org.junit.Before;
import org.junit.Test;
public class SimpleHttpRequestsUnitTest {
private URI httpURI;
@Before
public void init() throws URISyntaxException {
httpURI = new URI("http://www.baeldung.com/");
}
@Test
public void quickGet() throws IOException, InterruptedException, URISyntaxException {
HttpRequest request = HttpRequest.create(httpURI).GET();
HttpResponse response = request.response();
int responseStatusCode = response.statusCode();
String responseBody = response.body(HttpResponse.asString());
assertTrue("Get response status code is bigger then 400", responseStatusCode < 400);
}
@Test
public void asynchronousGet() throws URISyntaxException, IOException, InterruptedException, ExecutionException {
HttpRequest request = HttpRequest.create(httpURI).GET();
long before = System.currentTimeMillis();
CompletableFuture<HttpResponse> futureResponse = request.responseAsync();
futureResponse.thenAccept(response -> {
String responseBody = response.body(HttpResponse.asString());
});
HttpResponse resp = futureResponse.get();
HttpHeaders hs = resp.headers();
assertTrue("There should be more then 1 header.", hs.map().size() > 1);
}
@Test
public void postMehtod() throws URISyntaxException, IOException, InterruptedException {
HttpRequest.Builder requestBuilder = HttpRequest.create(httpURI);
requestBuilder.body(HttpRequest.fromString("param1=foo,param2=bar")).followRedirects(HttpClient.Redirect.SECURE);
HttpRequest request = requestBuilder.POST();
HttpResponse response = request.response();
int statusCode = response.statusCode();
assertTrue("HTTP return code", statusCode == HTTP_OK);
}
@Test
public void configureHttpClient() throws NoSuchAlgorithmException, URISyntaxException, IOException, InterruptedException {
CookieManager cManager = new CookieManager();
cManager.setCookiePolicy(CookiePolicy.ACCEPT_ORIGINAL_SERVER);
SSLParameters sslParam = new SSLParameters(new String[] { "TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256" }, new String[] { "TLSv1.2" });
HttpClient.Builder hcBuilder = HttpClient.create();
hcBuilder.cookieManager(cManager).sslContext(SSLContext.getDefault()).sslParameters(sslParam);
HttpClient httpClient = hcBuilder.build();
HttpRequest.Builder reqBuilder = httpClient.request(new URI("https://www.facebook.com"));
HttpRequest request = reqBuilder.followRedirects(HttpClient.Redirect.ALWAYS).GET();
HttpResponse response = request.response();
int statusCode = response.statusCode();
assertTrue("HTTP return code", statusCode == HTTP_OK);
}
SSLParameters getDefaultSSLParameters() throws NoSuchAlgorithmException {
SSLParameters sslP1 = SSLContext.getDefault().getSupportedSSLParameters();
String[] proto = sslP1.getApplicationProtocols();
String[] cifers = sslP1.getCipherSuites();
System.out.println(printStringArr(proto));
System.out.println(printStringArr(cifers));
return sslP1;
}
String printStringArr(String... args) {
if (args == null) {
return null;
}
StringBuilder sb = new StringBuilder();
for (String s : args) {
sb.append(s);
sb.append("\n");
}
return sb.toString();
}
String printHeaders(HttpHeaders h) {
if (h == null) {
return null;
}
StringBuilder sb = new StringBuilder();
Map<String, List<String>> hMap = h.map();
for (String k : hMap.keySet()) {
sb.append(k).append(":");
List<String> l = hMap.get(k);
if (l != null) {
l.forEach(s -> {
sb.append(s).append(",");
});
}
sb.append("\n");
}
return sb.toString();
}
}

152
core-java-9/src/test/java/com/baeldung/java9/methodhandles/MethodHandlesTest.java Normal file
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package com.baeldung.java9.methodhandles;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.*;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.lang.invoke.WrongMethodTypeException;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Arrays;
import java.util.List;
import org.junit.Test;
/**
* Test case for the {@link MethodHandles} API
*/
public class MethodHandlesTest {
@Test
public void givenConcatMethodHandle_whenInvoked_thenCorrectlyConcatenated() throws Throwable {
MethodHandles.Lookup publicLookup = MethodHandles.publicLookup();
MethodType mt = MethodType.methodType(String.class, String.class);
MethodHandle concatMH = publicLookup.findVirtual(String.class, "concat", mt);
String output = (String) concatMH.invoke("Effective ", "Java");
assertEquals("Effective Java", output);
}
@Test
public void givenAsListMethodHandle_whenInvokingWithArguments_thenCorrectlyInvoked() throws Throwable {
MethodHandles.Lookup publicLookup = MethodHandles.publicLookup();
MethodType mt = MethodType.methodType(List.class, Object[].class);
MethodHandle asListMH = publicLookup.findStatic(Arrays.class, "asList", mt);
List<Integer> list = (List<Integer>) asListMH.invokeWithArguments(1, 2);
assertThat(Arrays.asList(1, 2), is(list));
}
@Test
public void givenConstructorMethodHandle_whenInvoked_thenObjectCreatedCorrectly() throws Throwable {
MethodHandles.Lookup publicLookup = MethodHandles.publicLookup();
MethodType mt = MethodType.methodType(void.class, String.class);
MethodHandle newIntegerMH = publicLookup.findConstructor(Integer.class, mt);
Integer integer = (Integer) newIntegerMH.invoke("1");
assertEquals(1, integer.intValue());
}
@Test
public void givenAFieldWithoutGetter_whenCreatingAGetter_thenCorrectlyInvoked() throws Throwable {
MethodHandles.Lookup lookup = MethodHandles.lookup();
MethodHandle getTitleMH = lookup.findGetter(Book.class, "title", String.class);
Book book = new Book("ISBN-1234", "Effective Java");
assertEquals("Effective Java", getTitleMH.invoke(book));
}
@Test
public void givenPrivateMethod_whenCreatingItsMethodHandle_thenCorrectlyInvoked() throws Throwable {
MethodHandles.Lookup lookup = MethodHandles.lookup();
Method formatBookMethod = Book.class.getDeclaredMethod("formatBook");
formatBookMethod.setAccessible(true);
MethodHandle formatBookMH = lookup.unreflect(formatBookMethod);
Book book = new Book("ISBN-123", "Java in Action");
assertEquals("ISBN-123 > Java in Action", formatBookMH.invoke(book));
}
@Test
public void givenReplaceMethod_whenUsingReflectionAndInvoked_thenCorrectlyReplaced() throws Throwable {
Method replaceMethod = String.class.getMethod("replace", char.class, char.class);
String string = (String) replaceMethod.invoke("jovo", 'o', 'a');
assertEquals("java", string);
}
@Test
public void givenReplaceMethodHandle_whenInvoked_thenCorrectlyReplaced() throws Throwable {
MethodHandles.Lookup publicLookup = MethodHandles.publicLookup();
MethodType mt = MethodType.methodType(String.class, char.class, char.class);
MethodHandle replaceMH = publicLookup.findVirtual(String.class, "replace", mt);
String replacedString = (String) replaceMH.invoke("jovo", Character.valueOf('o'), 'a');
assertEquals("java", replacedString);
}
@Test
public void givenReplaceMethodHandle_whenInvokingExact_thenCorrectlyReplaced() throws Throwable {
MethodHandles.Lookup lookup = MethodHandles.lookup();
MethodType mt = MethodType.methodType(String.class, char.class, char.class);
MethodHandle replaceMH = lookup.findVirtual(String.class, "replace", mt);
String s = (String) replaceMH.invokeExact("jovo", 'o', 'a');
assertEquals("java", s);
}
@Test
public void givenSumMethodHandle_whenInvokingExact_thenSumIsCorrect() throws Throwable {
MethodHandles.Lookup lookup = MethodHandles.lookup();
MethodType mt = MethodType.methodType(int.class, int.class, int.class);
MethodHandle sumMH = lookup.findStatic(Integer.class, "sum", mt);
int sum = (int) sumMH.invokeExact(1, 11);
assertEquals(12, sum);
}
@Test(expected = WrongMethodTypeException.class)
public void givenSumMethodHandleAndIncompatibleArguments_whenInvokingExact_thenException() throws Throwable {
MethodHandles.Lookup lookup = MethodHandles.lookup();
MethodType mt = MethodType.methodType(int.class, int.class, int.class);
MethodHandle sumMH = lookup.findStatic(Integer.class, "sum", mt);
sumMH.invokeExact(Integer.valueOf(1), 11);
}
@Test
public void givenSpreadedEqualsMethodHandle_whenInvokedOnArray_thenCorrectlyEvaluated() throws Throwable {
MethodHandles.Lookup publicLookup = MethodHandles.publicLookup();
MethodType mt = MethodType.methodType(boolean.class, Object.class);
MethodHandle equalsMH = publicLookup.findVirtual(String.class, "equals", mt);
MethodHandle methodHandle = equalsMH.asSpreader(Object[].class, 2);
assertTrue((boolean) methodHandle.invoke(new Object[] { "java", "java" }));
assertFalse((boolean) methodHandle.invoke(new Object[] { "java", "jova" }));
}
@Test
public void givenConcatMethodHandle_whenBindToAString_thenCorrectlyConcatenated() throws Throwable {
MethodHandles.Lookup publicLookup = MethodHandles.publicLookup();
MethodType mt = MethodType.methodType(String.class, String.class);
MethodHandle concatMH = publicLookup.findVirtual(String.class, "concat", mt);
MethodHandle bindedConcatMH = concatMH.bindTo("Hello ");
assertEquals("Hello World!", bindedConcatMH.invoke("World!"));
}
}

1
core-java-concurrency/README.md
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@ -33,3 +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)
- [ExecutorService - Waiting for Threads to Finish](http://www.baeldung.com/java-executor-wait-for-threads)

25
core-java-concurrency/src/main/java/com/baeldung/concurrent/prioritytaskexecution/Job.java Normal file
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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) {
}
}
}

7
core-java-concurrency/src/main/java/com/baeldung/concurrent/prioritytaskexecution/JobPriority.java Normal file
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@ -0,0 +1,7 @@
package com.baeldung.concurrent.prioritytaskexecution;
public enum JobPriority {
HIGH,
MEDIUM,
LOW
}

56
core-java-concurrency/src/main/java/com/baeldung/concurrent/prioritytaskexecution/PriorityJobScheduler.java Normal file
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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 =
Executors.newSingleThreadExecutor();
private PriorityBlockingQueue<Job> priorityQueue;
public PriorityJobScheduler(Integer poolSize, Integer queueSize) {
priorityJobPoolExecutor = Executors.newFixedThreadPool(poolSize);
priorityQueue = new PriorityBlockingQueue<Job>(queueSize,
Comparator.comparing(Job::getJobPriority));
priorityJobScheduler.execute(()->{
while (true) {
try {
priorityJobPoolExecutor.execute(priorityQueue.take());
} catch (InterruptedException e) {
// exception needs special handling
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);
}
}

31
core-java-concurrency/src/main/java/com/baeldung/concurrent/threadlifecycle/BlockedState.java Normal file
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package com.baeldung.concurrent.threadlifecycle;
public class BlockedState {
public static void main(String[] args) throws InterruptedException {
Thread t1 = new Thread(new DemoThreadB());
Thread t2 = new Thread(new DemoThreadB());
t1.start();
t2.start();
Thread.sleep(1000);
System.out.println(t2.getState());
System.exit(0);
}
}
class DemoThreadB implements Runnable {
@Override
public void run() {
commonResource();
}
public static synchronized void commonResource() {
while(true) {
// Infinite loop to mimic heavy processing
// Thread 't1' won't leave this method
// when Thread 't2' enters this
}
}
}

14
core-java-concurrency/src/main/java/com/baeldung/concurrent/threadlifecycle/NewState.java Normal file
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@ -0,0 +1,14 @@
package com.baeldung.concurrent.threadlifecycle;
public class NewState implements Runnable {
public static void main(String[] args) {
Runnable runnable = new NewState();
Thread t = new Thread(runnable);
System.out.println(t.getState());
}
@Override
public void run() {
}
}

15
core-java-concurrency/src/main/java/com/baeldung/concurrent/threadlifecycle/RunnableState.java Normal file
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@ -0,0 +1,15 @@
package com.baeldung.concurrent.threadlifecycle;
public class RunnableState implements Runnable {
public static void main(String[] args) {
Runnable runnable = new NewState();
Thread t = new Thread(runnable);
t.start();
System.out.println(t.getState());
}
@Override
public void run() {
}
}

15
core-java-concurrency/src/main/java/com/baeldung/concurrent/threadlifecycle/TerminatedState.java Normal file
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@ -0,0 +1,15 @@
package com.baeldung.concurrent.threadlifecycle;
public class TerminatedState implements Runnable {
public static void main(String[] args) throws InterruptedException {
Thread t1 = new Thread(new TerminatedState());
t1.start();
Thread.sleep(1000);
System.out.println(t1.getState());
}
@Override
public void run() {
// No processing in this block
}
}

25
core-java-concurrency/src/main/java/com/baeldung/concurrent/threadlifecycle/TimedWaitingState.java Normal file
View File

@ -0,0 +1,25 @@
package com.baeldung.concurrent.threadlifecycle;
public class TimedWaitingState {
public static void main(String[] args) throws InterruptedException {
DemoThread obj1 = new DemoThread();
Thread t1 = new Thread(obj1);
t1.start();
// The following sleep will give enough time for ThreadScheduler
// to start processing of thread t1
Thread.sleep(1000);
System.out.println(t1.getState());
}
}
class DemoThread implements Runnable {
@Override
public void run() {
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
e.printStackTrace();
}
}
}

35
core-java-concurrency/src/main/java/com/baeldung/concurrent/threadlifecycle/WaitingState.java Normal file
View File

@ -0,0 +1,35 @@
package com.baeldung.concurrent.threadlifecycle;
public class WaitingState implements Runnable {
public static Thread t1;
public static void main(String[] args) {
t1 = new Thread(new WaitingState());
t1.start();
}
public void run() {
Thread t2 = new Thread(new DemoThreadWS());
t2.start();
try {
t2.join();
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
e.printStackTrace();
}
}
}
class DemoThreadWS implements Runnable {
public void run() {
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
e.printStackTrace();
}
System.out.println(WaitingState.t1.getState());
}
}

10
core-java-concurrency/src/main/java/com/baeldung/concurrent/waitandnotify/Data.java
View File

@ -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;

5
core-java-concurrency/src/main/java/com/baeldung/concurrent/waitandnotify/Receiver.java
View File

@ -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");
}
}
}
}

15
core-java-concurrency/src/main/java/com/baeldung/concurrent/waitandnotify/Sender.java
View File

@ -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");
}
}
}
}

40
core-java-concurrency/src/test/java/com/baeldung/concurrent/prioritytaskexecution/PriorityJobSchedulerUnitTest.java Normal file
View File

@ -0,0 +1,40 @@
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 e) {
Thread.currentThread().interrupt();
throw new RuntimeException(e);
}
pjs.closeScheduler();
}
}

2
core-java-concurrency/src/test/java/com/baeldung/concurrent/stopping/StopThreadTest.java → core-java-concurrency/src/test/java/com/baeldung/concurrent/stopping/StopThreadManualTest.java
View File

@ -10,7 +10,7 @@ import org.junit.Test;
import com.jayway.awaitility.Awaitility;
public class StopThreadTest {
public class StopThreadManualTest {
@Test
public void whenStoppedThreadIsStopped() throws InterruptedException {

79
core-java-concurrency/src/test/java/com/baeldung/concurrent/waitandnotify/NetworkIntegrationTest.java
View File

@ -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());
}
}

25
core-java-io/.gitignore vendored
View File

@ -1,26 +1,5 @@
*.class
0.*
#folders#
/target
/neoDb*
/data
/src/main/webapp/WEB-INF/classes
*/META-INF/*
.resourceCache
# Packaged files #
*.jar
*.war
*.ear
# Files generated by integration tests
*.txt
backup-pom.xml
/bin/
/temp
#IntelliJ specific
.idea/
*.iml
# *.txt
/temp

118
core-java-io/pom.xml
View File

@ -1,5 +1,4 @@
<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">
<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>core-java-io</artifactId>
@ -211,16 +210,6 @@
<artifactId>jmh-generator-annprocess</artifactId>
<version>1.19</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.3.4.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
<version>1.5.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
@ -264,99 +253,6 @@
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>copy-dependencies</id>
<phase>prepare-package</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/libs</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>libs/</classpathPrefix>
<mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
<configuration>
<archiveBaseDirectory>${project.basedir}</archiveBaseDirectory>
<archive>
<manifest>
<mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
</manifest>
</archive>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>shade</goal>
</goals>
<configuration>
<shadedArtifactAttached>true</shadedArtifactAttached>
<transformers>
<transformer
implementation="org.apache.maven.plugins.shade.resource.ManifestResourceTransformer">
<mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
</transformer>
</transformers>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<groupId>com.jolira</groupId>
<artifactId>onejar-maven-plugin</artifactId>
<executions>
<execution>
<configuration>
<mainClass>org.baeldung.executable.ExecutableMavenJar</mainClass>
<attachToBuild>true</attachToBuild>
<filename>${project.build.finalName}-onejar.${project.packaging}</filename>
</configuration>
<goals>
<goal>one-jar</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
@ -384,19 +280,19 @@
<argument>-Xmx300m</argument>
<argument>-XX:+UseParallelGC</argument>
<argument>-classpath</argument>
<classpath/>
<classpath />
<argument>com.baeldung.outofmemoryerror.OutOfMemoryGCLimitExceed</argument>
</arguments>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-javadoc-plugin</artifactId>
<version>3.0.0-M1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<target>1.8</target>
</configuration>
</plugin>
@ -442,7 +338,7 @@
<executions>
<execution>
<id>run-benchmarks</id>
<!-- <phase>integration-test</phase>-->
<!-- <phase>integration-test</phase> -->
<phase>none</phase>
<goals>
<goal>exec</goal>
@ -452,7 +348,7 @@
<executable>java</executable>
<arguments>
<argument>-classpath</argument>
<classpath/>
<classpath />
<argument>org.openjdk.jmh.Main</argument>
<argument>.*</argument>
</arguments>
@ -490,7 +386,7 @@
<protonpack.version>1.13</protonpack.version>
<streamex.version>0.6.5</streamex.version>
<vavr.version>0.9.0</vavr.version>
<!-- testing -->
<org.hamcrest.version>1.3</org.hamcrest.version>
<junit.version>4.12</junit.version>

4
core-java-io/src/main/java/com/baeldung/java/nio2/watcher/DirectoryWatcherExample.java
View File

@ -10,7 +10,7 @@ import java.nio.file.WatchKey;
import java.nio.file.WatchService;
public class DirectoryWatcherExample {
public static void main(String[] args) throws IOException, InterruptedException {
WatchService watchService = FileSystems.getDefault().newWatchService();
Path path = Paths.get(System.getProperty("user.home"));
@ -25,5 +25,5 @@ public class DirectoryWatcherExample {
watchService.close();
}
}

2
core-java-io/src/main/resources/targetFile.tmp
View File

@ -1,2 +0,0 @@
line 1
a second line

85
core-java-io/src/test/java/com/baeldung/copyfiles/FileCopierTest.java
View File

@ -19,52 +19,51 @@ import org.junit.Test;
import static org.assertj.core.api.Assertions.*;
public class FileCopierTest {
File original = new File("src/test/resources/original.txt");
File original = new File("src/test/resources/original.txt");
@Before
public void init() throws IOException {
if (!original.exists())
Files.createFile(original.toPath());
}
@Before
public void init() throws IOException {
if (!original.exists())
Files.createFile(original.toPath());
}
@Test
public void givenIoAPI_whenCopied_thenCopyExistsWithSameContents() throws IOException {
File copied = new File("src/test/resources/copiedWithIo.txt");
try (InputStream in = new BufferedInputStream(new FileInputStream(original));
OutputStream out = new BufferedOutputStream(new FileOutputStream(copied))) {
byte[] buffer = new byte[1024];
int lengthRead;
while ((lengthRead = in.read(buffer)) > 0) {
out.write(buffer, 0, lengthRead);
out.flush();
}
}
assertThat(copied).exists();
assertThat(Files.readAllLines(original.toPath()).equals(Files.readAllLines(copied.toPath())));
}
@Test
public void givenIoAPI_whenCopied_thenCopyExistsWithSameContents() throws IOException {
File copied = new File("src/test/resources/copiedWithIo.txt");
try (InputStream in = new BufferedInputStream(new FileInputStream(original)); OutputStream out = new BufferedOutputStream(new FileOutputStream(copied))) {
byte[] buffer = new byte[1024];
int lengthRead;
while ((lengthRead = in.read(buffer)) > 0) {
out.write(buffer, 0, lengthRead);
out.flush();
}
}
assertThat(copied).exists();
assertThat(Files.readAllLines(original.toPath()).equals(Files.readAllLines(copied.toPath())));
}
@Test
public void givenCommonsIoAPI_whenCopied_thenCopyExistsWithSameContents() throws IOException {
File copied = new File("src/test/resources/copiedWithApacheCommons.txt");
FileUtils.copyFile(original, copied);
assertThat(copied).exists();
assertThat(Files.readAllLines(original.toPath()).equals(Files.readAllLines(copied.toPath())));
}
@Test
public void givenCommonsIoAPI_whenCopied_thenCopyExistsWithSameContents() throws IOException {
File copied = new File("src/test/resources/copiedWithApacheCommons.txt");
FileUtils.copyFile(original, copied);
assertThat(copied).exists();
assertThat(Files.readAllLines(original.toPath()).equals(Files.readAllLines(copied.toPath())));
}
@Test
public void givenNIO2_whenCopied_thenCopyExistsWithSameContents() throws IOException {
Path copied = Paths.get("src/test/resources/copiedWithNio.txt");
Path originalPath = original.toPath();
Files.copy(originalPath, copied, StandardCopyOption.REPLACE_EXISTING);
assertThat(copied).exists();
assertThat(Files.readAllLines(originalPath).equals(Files.readAllLines(copied)));
}
@Test
public void givenNIO2_whenCopied_thenCopyExistsWithSameContents() throws IOException {
Path copied = Paths.get("src/test/resources/copiedWithNio.txt");
Path originalPath = original.toPath();
Files.copy(originalPath, copied, StandardCopyOption.REPLACE_EXISTING);
assertThat(copied).exists();
assertThat(Files.readAllLines(originalPath).equals(Files.readAllLines(copied)));
}
@Test
public void givenGuava_whenCopied_thenCopyExistsWithSameContents() throws IOException {
File copied = new File("src/test/resources/copiedWithApacheCommons.txt");
com.google.common.io.Files.copy(original, copied);
assertThat(copied).exists();
assertThat(Files.readAllLines(original.toPath()).equals(Files.readAllLines(copied.toPath())));
}
@Test
public void givenGuava_whenCopied_thenCopyExistsWithSameContents() throws IOException {
File copied = new File("src/test/resources/copiedWithApacheCommons.txt");
com.google.common.io.Files.copy(original, copied);
assertThat(copied).exists();
assertThat(Files.readAllLines(original.toPath()).equals(Files.readAllLines(copied.toPath())));
}
}

1
core-java-io/src/test/java/com/baeldung/file/FileOperationsManualTest.java
View File

@ -3,7 +3,6 @@ package com.baeldung.file;
import org.apache.commons.io.FileUtils;
import org.hamcrest.CoreMatchers;
import org.hamcrest.Matchers;
import org.junit.Assert;
import org.junit.Test;
import java.io.BufferedReader;

22
core-java-io/src/test/java/com/baeldung/file/FilesTest.java
View File

@ -42,19 +42,14 @@ public class FilesTest {
CharSink chs = com.google.common.io.Files.asCharSink(file, Charsets.UTF_8, FileWriteMode.APPEND);
chs.write("Spain\r\n");
assertThat(StreamUtils.getStringFromInputStream(
new FileInputStream(fileName)))
.isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
assertThat(StreamUtils.getStringFromInputStream(new FileInputStream(fileName))).isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
}
@Test
public void whenAppendToFileUsingFiles_thenCorrect() throws IOException {
Files.write(Paths.get(fileName), "Spain\r\n".getBytes(), StandardOpenOption.APPEND);
assertThat(StreamUtils.getStringFromInputStream(
new FileInputStream(fileName)))
.isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
assertThat(StreamUtils.getStringFromInputStream(new FileInputStream(fileName))).isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
}
@Test
@ -62,9 +57,7 @@ public class FilesTest {
File file = new File(fileName);
FileUtils.writeStringToFile(file, "Spain\r\n", StandardCharsets.UTF_8, true);
assertThat(StreamUtils.getStringFromInputStream(
new FileInputStream(fileName)))
.isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
assertThat(StreamUtils.getStringFromInputStream(new FileInputStream(fileName))).isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
}
@Test
@ -73,9 +66,7 @@ public class FilesTest {
fos.write("Spain\r\n".getBytes());
fos.close();
assertThat(StreamUtils.getStringFromInputStream(
new FileInputStream(fileName)))
.isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
assertThat(StreamUtils.getStringFromInputStream(new FileInputStream(fileName))).isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\r\n");
}
@Test
@ -86,9 +77,6 @@ public class FilesTest {
bw.newLine();
bw.close();
assertThat(
StreamUtils.getStringFromInputStream(
new FileInputStream(fileName)))
.isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\n");
assertThat(StreamUtils.getStringFromInputStream(new FileInputStream(fileName))).isEqualTo("UK\r\n" + "US\r\n" + "Germany\r\n" + "Spain\n");
}
}

4
core-java-io/src/test/java/com/baeldung/filesystem/jndi/test/LookupFSJNDIIntegrationTest.java
View File

@ -35,7 +35,7 @@ public class LookupFSJNDIIntegrationTest {
@Test
public void givenInitialContext_whenLokupFileExists_thenSuccess() {
File file = fsjndi.getFile(FILENAME);
assertNotNull("File exists", file);
File file = fsjndi.getFile(FILENAME);
assertNotNull("File exists", file);
}
}

1
core-java-io/src/test/java/com/baeldung/java/nio2/PathManualTest.java
View File

@ -9,7 +9,6 @@ import java.net.URI;
import java.nio.file.NoSuchFileException;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Date;
import org.junit.Test;

55
core-java-io/src/test/java/com/baeldung/java/nio2/async/AsyncFileIntegrationTest.java
View File

@ -17,18 +17,19 @@ import java.util.concurrent.Future;
import static org.junit.Assert.assertEquals;
public class AsyncFileIntegrationTest {
@Test
public void givenPath_whenReadsContentWithFuture_thenCorrect() throws IOException, ExecutionException, InterruptedException {
Path path = Paths.get(URI.create(this.getClass().getClassLoader().getResource("file.txt").toString()));
AsynchronousFileChannel fileChannel = AsynchronousFileChannel.open(path, StandardOpenOption.READ);
final Path path = Paths.get(URI.create(this.getClass().getClassLoader().getResource("file.txt").toString()));
final AsynchronousFileChannel fileChannel = AsynchronousFileChannel.open(path, StandardOpenOption.READ);
ByteBuffer buffer = ByteBuffer.allocate(1024);
final ByteBuffer buffer = ByteBuffer.allocate(1024);
Future<Integer> operation = fileChannel.read(buffer, 0);
final Future<Integer> operation = fileChannel.read(buffer, 0);
operation.get();
String fileContent = new String(buffer.array()).trim();
final String fileContent = new String(buffer.array()).trim();
buffer.clear();
assertEquals(fileContent, "baeldung.com");
@ -36,18 +37,16 @@ public class AsyncFileIntegrationTest {
@Test
public void givenPath_whenReadsContentWithCompletionHandler_thenCorrect() throws IOException {
Path path = Paths.get(URI.create(AsyncFileIntegrationTest.class.getResource("/file.txt").toString()));
AsynchronousFileChannel fileChannel = AsynchronousFileChannel.open(path, StandardOpenOption.READ);
final Path path = Paths.get(URI.create(this.getClass().getClassLoader().getResource("file.txt").toString()));
final AsynchronousFileChannel fileChannel = AsynchronousFileChannel.open(path, StandardOpenOption.READ);
ByteBuffer buffer = ByteBuffer.allocate(1024);
final ByteBuffer buffer = ByteBuffer.allocate(1024);
fileChannel.read(buffer, 0, buffer, new CompletionHandler<Integer, ByteBuffer>() {
@Override
public void completed(Integer result, ByteBuffer attachment) {
// result is number of bytes read
// attachment is the buffer
}
@Override
@ -59,42 +58,40 @@ public class AsyncFileIntegrationTest {
@Test
public void givenPathAndContent_whenWritesToFileWithFuture_thenCorrect() throws IOException, ExecutionException, InterruptedException {
String fileName = "temp";
Path path = Paths.get(fileName);
AsynchronousFileChannel fileChannel = AsynchronousFileChannel.open(path, StandardOpenOption.WRITE, StandardOpenOption.CREATE);
final String fileName = "temp";
final Path path = Paths.get(fileName);
final AsynchronousFileChannel fileChannel = AsynchronousFileChannel.open(path, StandardOpenOption.WRITE, StandardOpenOption.CREATE);
ByteBuffer buffer = ByteBuffer.allocate(1024);
long position = 0;
final ByteBuffer buffer = ByteBuffer.allocate(1024);
final long position = 0;
buffer.put("hello world".getBytes());
buffer.flip();
Future<Integer> operation = fileChannel.write(buffer, position);
final Future<Integer> operation = fileChannel.write(buffer, position);
buffer.clear();
operation.get();
String content = readContent(path);
final String content = readContent(path);
assertEquals("hello world", content);
}
@Test
public void givenPathAndContent_whenWritesToFileWithHandler_thenCorrect() throws IOException {
String fileName = UUID.randomUUID().toString();
Path path = Paths.get(fileName);
AsynchronousFileChannel fileChannel = AsynchronousFileChannel.open(path, StandardOpenOption.WRITE, StandardOpenOption.CREATE, StandardOpenOption.DELETE_ON_CLOSE);
final String fileName = UUID.randomUUID().toString();
final Path path = Paths.get(fileName);
final AsynchronousFileChannel fileChannel = AsynchronousFileChannel.open(path, StandardOpenOption.WRITE, StandardOpenOption.CREATE, StandardOpenOption.DELETE_ON_CLOSE);
ByteBuffer buffer = ByteBuffer.allocate(1024);
final ByteBuffer buffer = ByteBuffer.allocate(1024);
buffer.put("hello world".getBytes());
buffer.flip();
fileChannel.write(buffer, 0, buffer, new CompletionHandler<Integer, ByteBuffer>() {
@Override
public void completed(Integer result, ByteBuffer attachment) {
// result is number of bytes written
// attachment is the buffer
}
@Override
@ -104,23 +101,25 @@ public class AsyncFileIntegrationTest {
});
}
public static String readContent(Path file) throws ExecutionException, InterruptedException {
//
private String readContent(Path file) throws ExecutionException, InterruptedException {
AsynchronousFileChannel fileChannel = null;
try {
fileChannel = AsynchronousFileChannel.open(file, StandardOpenOption.READ);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
ByteBuffer buffer = ByteBuffer.allocate(1024);
final ByteBuffer buffer = ByteBuffer.allocate(1024);
Future<Integer> operation = fileChannel.read(buffer, 0);
final Future<Integer> operation = fileChannel.read(buffer, 0);
operation.get();
String fileContent = new String(buffer.array()).trim();
final String fileContent = new String(buffer.array()).trim();
buffer.clear();
return fileContent;
}
}

1
core-java-io/src/test/java/com/baeldung/java/nio2/attributes/BasicAttribsIntegrationTest.java
View File

@ -20,7 +20,6 @@ public class BasicAttribsIntegrationTest {
private static final Logger LOG = LoggerFactory.getLogger(BasicAttribsIntegrationTest.class);
private static final String HOME = System.getProperty("user.home");
private static BasicFileAttributes basicAttribs;

15
core-java-io/src/test/java/com/baeldung/java8/JavaFolderSizeUnitTest.java
View File

@ -55,12 +55,7 @@ public class JavaFolderSizeUnitTest {
@Test
public void whenGetFolderSizeUsingJava8_thenCorrect() throws IOException {
final Path folder = Paths.get(path);
final long size = Files.walk(folder)
.filter(p -> p.toFile()
.isFile())
.mapToLong(p -> p.toFile()
.length())
.sum();
final long size = Files.walk(folder).filter(p -> p.toFile().isFile()).mapToLong(p -> p.toFile().length()).sum();
assertEquals(EXPECTED_SIZE, size);
}
@ -77,12 +72,8 @@ public class JavaFolderSizeUnitTest {
public void whenGetFolderSizeUsingGuava_thenCorrect() {
final File folder = new File(path);
final Iterable<File> files = com.google.common.io.Files.fileTreeTraverser()
.breadthFirstTraversal(folder);
final long size = StreamSupport.stream(files.spliterator(), false)
.filter(File::isFile)
.mapToLong(File::length)
.sum();
final Iterable<File> files = com.google.common.io.Files.fileTreeTraverser().breadthFirstTraversal(folder);
final long size = StreamSupport.stream(files.spliterator(), false).filter(File::isFile).mapToLong(File::length).sum();
assertEquals(EXPECTED_SIZE, size);
}

28
core-java-io/src/test/java/com/baeldung/mappedbytebuffer/MappedByteBufferUnitTest.java
View File

@ -18,14 +18,13 @@ import static org.junit.Assert.assertNotNull;
public class MappedByteBufferUnitTest {
@Test
public void givenFileChannel_whenReadToTheMappedByteBuffer_thenShouldSuccess() throws Exception {
//given
// given
CharBuffer charBuffer = null;
Path pathToRead = getFileURIFromResources("fileToRead.txt");
//when
// when
try (FileChannel fileChannel = (FileChannel) Files.newByteChannel(pathToRead, EnumSet.of(StandardOpenOption.READ))) {
MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_ONLY, 0, fileChannel.size());
@ -34,20 +33,19 @@ public class MappedByteBufferUnitTest {
}
}
//then
// then
assertNotNull(charBuffer);
assertEquals(charBuffer.toString(), "This is a content of the file");
}
@Test
public void givenPath_whenWriteToItUsingMappedByteBuffer_thenShouldSuccessfullyWrite() throws Exception {
//given
CharBuffer charBuffer = CharBuffer.wrap("This will be written to the file");
Path pathToWrite = getFileURIFromResources("fileToWriteTo.txt");
// given
final CharBuffer charBuffer = CharBuffer.wrap("This will be written to the file");
final Path pathToWrite = getFileURIFromResources("fileToWriteTo.txt");
//when
try (FileChannel fileChannel = (FileChannel) Files.newByteChannel(pathToWrite,
EnumSet.of(StandardOpenOption.READ, StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING))) {
// when
try (FileChannel fileChannel = (FileChannel) Files.newByteChannel(pathToWrite, EnumSet.of(StandardOpenOption.READ, StandardOpenOption.WRITE, StandardOpenOption.TRUNCATE_EXISTING))) {
MappedByteBuffer mappedByteBuffer = fileChannel.map(FileChannel.MapMode.READ_WRITE, 0, charBuffer.length());
if (mappedByteBuffer != null) {
@ -55,14 +53,16 @@ public class MappedByteBufferUnitTest {
}
}
//then
List<String> fileContent = Files.readAllLines(pathToWrite);
// then
final List<String> fileContent = Files.readAllLines(pathToWrite);
assertEquals(fileContent.get(0), "This will be written to the file");
}
private Path getFileURIFromResources(String fileName) throws Exception {
ClassLoader classLoader = getClass().getClassLoader();
//
private final Path getFileURIFromResources(String fileName) throws Exception {
final ClassLoader classLoader = getClass().getClassLoader();
return Paths.get(classLoader.getResource(fileName).toURI());
}
}

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