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[BAEL-9044] - Moved articles out of core-java

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This commit is contained in:
amit2103
2018-12-23 16:32:19 +05:30
parent be2e45b0a5
commit ec53cb77ac
34 changed files with 57 additions and 21 deletions
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14
core-java/README.md
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@@ -7,7 +7,6 @@
- [How to Run a Shell Command in Java](http://www.baeldung.com/run-shell-command-in-java)
- [MD5 Hashing in Java](http://www.baeldung.com/java-md5)
- [A Guide to Java Sockets](http://www.baeldung.com/a-guide-to-java-sockets)
- [Guide to the Fork/Join Framework in Java](http://www.baeldung.com/java-fork-join)
- [How to Print Screen in Java](http://www.baeldung.com/print-screen-in-java)
- [A Guide To Java Regular Expressions API](http://www.baeldung.com/regular-expressions-java)
- [Getting Started with Java Properties](http://www.baeldung.com/java-properties)
@@ -27,13 +26,11 @@
- [Guide to UUID in Java](http://www.baeldung.com/java-uuid)
- [Guide to Escaping Characters in Java RegExps](http://www.baeldung.com/java-regexp-escape-char)
- [Difference between URL and URI](http://www.baeldung.com/java-url-vs-uri)
- [Broadcasting and Multicasting in Java](http://www.baeldung.com/java-broadcast-multicast)
- [OutOfMemoryError: GC Overhead Limit Exceeded](http://www.baeldung.com/java-gc-overhead-limit-exceeded)
- [Creating a Java Compiler Plugin](http://www.baeldung.com/java-build-compiler-plugin)
- [Quick Guide to Java Stack](http://www.baeldung.com/java-stack)
- [Guide to java.util.Formatter](http://www.baeldung.com/java-string-formatter)
- [Guide to the Cipher Class](http://www.baeldung.com/java-cipher-class)
- [A Guide to ThreadLocalRandom in Java](http://www.baeldung.com/java-thread-local-random)
- [Compiling Java *.class Files with javac](http://www.baeldung.com/javac)
- [A Guide to Iterator in Java](http://www.baeldung.com/java-iterator)
- [Introduction to Javadoc](http://www.baeldung.com/javadoc)
@@ -42,31 +39,20 @@
- [How to Detect the OS Using Java](http://www.baeldung.com/java-detect-os)
- [ASCII Art in Java](http://www.baeldung.com/ascii-art-in-java)
- [What is the serialVersionUID?](http://www.baeldung.com/java-serial-version-uid)
- [A Guide To UDP In Java](http://www.baeldung.com/udp-in-java)
- [A Guide to the ResourceBundle](http://www.baeldung.com/java-resourcebundle)
- [Class Loaders in Java](http://www.baeldung.com/java-classloaders)
- [Sending Emails with Java](http://www.baeldung.com/java-email)
- [Introduction to SSL in Java](http://www.baeldung.com/java-ssl)
- [Java KeyStore API](http://www.baeldung.com/java-keystore)
- [Double-Checked Locking with Singleton](http://www.baeldung.com/java-singleton-double-checked-locking)
- [Guide to Java Clock Class](http://www.baeldung.com/java-clock)
- [Introduction to Creational Design Patterns](http://www.baeldung.com/creational-design-patterns)
- [Proxy, Decorator, Adapter and Bridge Patterns](http://www.baeldung.com/java-structural-design-patterns)
- [Singletons in Java](http://www.baeldung.com/java-singleton)
- [Flyweight Pattern in Java](http://www.baeldung.com/java-flyweight)
- [The Observer Pattern in Java](http://www.baeldung.com/java-observer-pattern)
- [Service Locator Pattern](http://www.baeldung.com/java-service-locator-pattern)
- [The Thread.join() Method in Java](http://www.baeldung.com/java-thread-join)
- [Importance of Main Manifest Attribute in a Self-Executing JAR](http://www.baeldung.com/java-jar-executable-manifest-main-class)
- [How to Get the File Extension of a File in Java](http://www.baeldung.com/java-file-extension)
- [Console I/O in Java](http://www.baeldung.com/java-console-input-output)
- [Java Global Exception Handler](http://www.baeldung.com/java-global-exception-handler)
- [Encrypting and Decrypting Files in Java](http://www.baeldung.com/java-cipher-input-output-stream)
- [How to Get the Size of an Object in Java](http://www.baeldung.com/java-size-of-object)
- [Guide to Java Instrumentation](http://www.baeldung.com/java-instrumentation)
- [Getting a File’s Mime Type in Java](http://www.baeldung.com/java-file-mime-type)
- [Common Java Exceptions](http://www.baeldung.com/java-common-exceptions)
- [Java Constructors vs Static Factory Methods](https://www.baeldung.com/java-constructors-vs-static-factory-methods)
- [Throw Exception in Optional in Java 8](https://www.baeldung.com/java-optional-throw-exception)
- [Add a Character to a String at a Given Position](https://www.baeldung.com/java-add-character-to-string)
- [Calculating the nth Root in Java](https://www.baeldung.com/java-nth-root)

6
core-java/pom.xml
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@@ -131,11 +131,6 @@
<artifactId>h2</artifactId>
<version>${h2database.version}</version>
</dependency>
<dependency>
<groupId>javax.mail</groupId>
<artifactId>mail</artifactId>
<version>${javax.mail.version}</version>
</dependency>
<!-- Mime Type Resolution Libraries -->
<dependency>
<groupId>org.apache.tika</groupId>
@@ -514,7 +509,6 @@
<jmh-generator-annprocess.version>1.19</jmh-generator-annprocess.version>
<maven-javadoc-plugin.version>3.0.0-M1</maven-javadoc-plugin.version>
<javax.mail.version>1.5.0-b01</javax.mail.version>
<maven-jar-plugin.version>3.0.2</maven-jar-plugin.version>
<onejar-maven-plugin.version>1.4.4</onejar-maven-plugin.version>
<maven-shade-plugin.version>3.1.1</maven-shade-plugin.version>

26
core-java/src/main/java/com/baeldung/console/ConsoleConsoleClass.java
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@@ -1,26 +0,0 @@
package com.baeldung.console;
import java.io.Console;
public class ConsoleConsoleClass {
public static void main(String[] args) {
Console console = System.console();
if (console == null) {
System.out.print("No console available");
return;
}
String progLanguauge = console.readLine("Enter your favourite programming language: ");
console.printf(progLanguauge + " is very interesting!");
char[] pass = console.readPassword("To finish, enter password: ");
if ("BAELDUNG".equals(pass.toString().toUpperCase()))
console.printf("Good! Regards!");
else
console.printf("Nice try. Regards.");
}
}

76
core-java/src/main/java/com/baeldung/console/ConsoleScannerClass.java
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@@ -1,76 +0,0 @@
package com.baeldung.console;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;
import java.util.regex.Pattern;
public class ConsoleScannerClass {
public static void main(String[] args) {
System.out.println("Please enter your name and surname: ");
Scanner scanner = new Scanner(System.in);
String nameSurname = scanner.nextLine();
System.out.println("Please enter your gender: ");
char gender = scanner.next().charAt(0);
System.out.println("Please enter your age: ");
int age = scanner.nextInt();
System.out.println("Please enter your height in meters: ");
double height = scanner.nextDouble();
System.out.println(nameSurname + ", " + age + ", is a great " + (gender == 'm' ? "guy" : "girl") + " with " + height + " meters height" + " and " + (gender == 'm' ? "he" : "she") + " reads Baeldung.");
System.out.print("Have a good");
System.out.print(" one!");
System.out.println("\nPlease enter number of years of experience as a developer: ");
BufferedReader buffReader = new BufferedReader(new InputStreamReader(System.in));
int i = 0;
try {
i = Integer.parseInt(buffReader.readLine());
} catch (NumberFormatException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("You are a " + (i > 5 ? "great" : "good") + " developer!");
int sum = 0, count = 0;
System.out.println("Please enter your college degrees. To finish, enter baeldung website url");
while (scanner.hasNextInt()) {
int nmbr = scanner.nextInt();
sum += nmbr;
count++;
}
int mean = sum / count;
System.out.println("Your average degree is " + mean);
if (scanner.hasNext(Pattern.compile("www.baeldung.com")))
System.out.println("Correct!");
else
System.out.println("Baeldung website url is www.baeldung.com");
if (scanner != null)
scanner.close();
}
}

12
core-java/src/main/java/com/baeldung/constructorsstaticfactorymethods/application/Application.java
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@@ -1,12 +0,0 @@
package com.baeldung.constructorsstaticfactorymethods.application;
import com.baeldung.constructorsstaticfactorymethods.entities.User;
public class Application {
public static void main(String[] args) {
User user1 = User.createWithDefaultCountry("John", "john@domain.com");
User user2 = User.createWithLoggedInstantiationTime("John", "john@domain.com", "Argentina");
User user3 = User.getSingletonInstance("John", "john@domain.com", "Argentina");
}
}

63
core-java/src/main/java/com/baeldung/constructorsstaticfactorymethods/entities/User.java
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@@ -1,63 +0,0 @@
package com.baeldung.constructorsstaticfactorymethods.entities;
import java.time.LocalTime;
import java.util.logging.ConsoleHandler;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.logging.SimpleFormatter;
public class User {
private static volatile User instance = null;
private static final Logger LOGGER = Logger.getLogger(User.class.getName());
private final String name;
private final String email;
private final String country;
public static User createWithDefaultCountry(String name, String email) {
return new User(name, email, "Argentina");
}
public static User createWithLoggedInstantiationTime(String name, String email, String country) {
setLoggerProperties();
LOGGER.log(Level.INFO, "Creating User instance at : {0}", LocalTime.now());
return new User(name, email, country);
}
public static User getSingletonInstance(String name, String email, String country) {
if (instance == null) {
synchronized (User.class) {
if (instance == null) {
instance = new User(name, email, country);
}
}
}
return instance;
}
private User(String name, String email, String country) {
this.name = name;
this.email = email;
this.country = country;
}
public String getName() {
return name;
}
public String getEmail() {
return email;
}
public String getCountry() {
return country;
}
private static void setLoggerProperties() {
ConsoleHandler handler = new ConsoleHandler();
handler.setLevel(Level.INFO);
handler.setFormatter(new SimpleFormatter());
LOGGER.addHandler(handler);
}
}

49
core-java/src/main/java/com/baeldung/forkjoin/CustomRecursiveAction.java
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@@ -1,49 +0,0 @@
package com.baeldung.forkjoin;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.ForkJoinTask;
import java.util.concurrent.RecursiveAction;
import java.util.logging.Logger;
public class CustomRecursiveAction extends RecursiveAction {
private String workLoad = "";
private static final int THRESHOLD = 4;
private static Logger logger = Logger.getAnonymousLogger();
public CustomRecursiveAction(String workLoad) {
this.workLoad = workLoad;
}
@Override
protected void compute() {
if (workLoad.length() > THRESHOLD) {
ForkJoinTask.invokeAll(createSubtasks());
} else {
processing(workLoad);
}
}
private Collection<CustomRecursiveAction> createSubtasks() {
List<CustomRecursiveAction> subtasks = new ArrayList<>();
String partOne = workLoad.substring(0, workLoad.length() / 2);
String partTwo = workLoad.substring(workLoad.length() / 2, workLoad.length());
subtasks.add(new CustomRecursiveAction(partOne));
subtasks.add(new CustomRecursiveAction(partTwo));
return subtasks;
}
private void processing(String work) {
String result = work.toUpperCase();
logger.info("This result - (" + result + ") - was processed by " + Thread.currentThread()
.getName());
}
}

42
core-java/src/main/java/com/baeldung/forkjoin/CustomRecursiveTask.java
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@@ -1,42 +0,0 @@
package com.baeldung.forkjoin;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.ForkJoinTask;
import java.util.concurrent.RecursiveTask;
public class CustomRecursiveTask extends RecursiveTask<Integer> {
private int[] arr;
private static final int THRESHOLD = 20;
public CustomRecursiveTask(int[] arr) {
this.arr = arr;
}
@Override
protected Integer compute() {
if (arr.length > THRESHOLD) {
return ForkJoinTask.invokeAll(createSubtasks()).stream().mapToInt(ForkJoinTask::join).sum();
} else {
return processing(arr);
}
}
private Collection<CustomRecursiveTask> createSubtasks() {
List<CustomRecursiveTask> dividedTasks = new ArrayList<>();
dividedTasks.add(new CustomRecursiveTask(Arrays.copyOfRange(arr, 0, arr.length / 2)));
dividedTasks.add(new CustomRecursiveTask(Arrays.copyOfRange(arr, arr.length / 2, arr.length)));
return dividedTasks;
}
private Integer processing(int[] arr) {
return Arrays.stream(arr).filter(a -> a > 10 && a < 27).map(a -> a * 10).sum();
}
}

9
core-java/src/main/java/com/baeldung/forkjoin/util/PoolUtil.java
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@@ -1,9 +0,0 @@
package com.baeldung.forkjoin.util;
import java.util.concurrent.ForkJoinPool;
public class PoolUtil {
public static ForkJoinPool forkJoinPool = new ForkJoinPool(2);
}

80
core-java/src/main/java/com/baeldung/mail/EmailService.java
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@@ -1,80 +0,0 @@
package com.baeldung.mail;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.util.Properties;
import javax.mail.*;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
public class EmailService {
private String host = "";
private int port = 0;
private String username = "";
private String password = "";
public EmailService(String host, int port, String username, String password) {
this.host = host;
this.port = port;
this.username = username;
this.password = password;
sendMail();
}
private void sendMail() {
Properties prop = new Properties();
prop.put("mail.smtp.auth", true);
prop.put("mail.smtp.starttls.enable", "true");
prop.put("mail.smtp.host", host);
prop.put("mail.smtp.port", port);
prop.put("mail.smtp.ssl.trust", host);
Session session = Session.getInstance(prop, new Authenticator() {
@Override
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication(username, password);
}
});
try {
Message message = new MimeMessage(session);
message.setFrom(new InternetAddress("from@gmail.com"));
message.setRecipients(Message.RecipientType.TO, InternetAddress.parse("to@gmail.com"));
message.setSubject("Mail Subject");
String msg = "This is my first email using JavaMailer";
MimeBodyPart mimeBodyPart = new MimeBodyPart();
mimeBodyPart.setContent(msg, "text/html");
MimeBodyPart attachmentBodyPart = new MimeBodyPart();
attachmentBodyPart.attachFile(new File("pom.xml"));
Multipart multipart = new MimeMultipart();
multipart.addBodyPart(mimeBodyPart);
multipart.addBodyPart(attachmentBodyPart);
message.setContent(multipart);
Transport.send(message);
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String ... args) {
new EmailService("smtp.mailtrap.io", 25, "87ba3d9555fae8", "91cb4379af43ed");
}
}

5
core-java/src/main/java/com/baeldung/networking/README.md
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@@ -1,5 +0,0 @@
### Relevant Articles:
- [A Guide To UDP In Java](http://www.baeldung.com/udp-in-java)
- [A Guide To HTTP Cookies In Java](http://www.baeldung.com/cookies-java)
- [A Guide to the Java URL](http://www.baeldung.com/java-url)
- [Working with Network Interfaces in Java](http://www.baeldung.com/java-network-interfaces)

57
core-java/src/main/java/com/baeldung/networking/cookies/PersistentCookieStore.java
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@@ -1,57 +0,0 @@
package com.baeldung.networking.cookies;
import java.net.*;
import java.util.List;
public class PersistentCookieStore implements CookieStore, Runnable {
CookieStore store;
public PersistentCookieStore() {
store = new CookieManager().getCookieStore();
// deserialize cookies into store
Runtime.getRuntime()
.addShutdownHook(new Thread(this));
}
@Override
public void run() {
// serialize cookies to persistent storage
}
@Override
public void add(URI uri, HttpCookie cookie) {
store.add(uri, cookie);
}
@Override
public List<HttpCookie> get(URI uri) {
// TODO Auto-generated method stub
return null;
}
@Override
public List<HttpCookie> getCookies() {
// TODO Auto-generated method stub
return null;
}
@Override
public List<URI> getURIs() {
// TODO Auto-generated method stub
return null;
}
@Override
public boolean remove(URI uri, HttpCookie cookie) {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean removeAll() {
// TODO Auto-generated method stub
return false;
}
}

26
core-java/src/main/java/com/baeldung/networking/cookies/ProxyAcceptCookiePolicy.java
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@@ -1,26 +0,0 @@
package com.baeldung.networking.cookies;
import java.net.*;
public class ProxyAcceptCookiePolicy implements CookiePolicy {
String acceptedProxy;
public ProxyAcceptCookiePolicy(String acceptedProxy) {
this.acceptedProxy = acceptedProxy;
}
public boolean shouldAccept(URI uri, HttpCookie cookie) {
String host;
try {
host = InetAddress.getByName(uri.getHost()).getCanonicalHostName();
} catch (UnknownHostException e) {
host = uri.getHost();
}
if (!HttpCookie.domainMatches(acceptedProxy, host)) {
return false;
}
return CookiePolicy.ACCEPT_ORIGINAL_SERVER.shouldAccept(uri, cookie);
}
}

42
core-java/src/main/java/com/baeldung/networking/udp/EchoClient.java
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@@ -1,42 +0,0 @@
package com.baeldung.networking.udp;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class EchoClient {
private DatagramSocket socket;
private InetAddress address;
private byte[] buf;
public EchoClient() {
try {
socket = new DatagramSocket();
address = InetAddress.getByName("localhost");
} catch (IOException e) {
e.printStackTrace();
}
}
public String sendEcho(String msg) {
DatagramPacket packet = null;
try {
buf = msg.getBytes();
packet = new DatagramPacket(buf, buf.length, address, 4445);
socket.send(packet);
packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
} catch (IOException e) {
e.printStackTrace();
}
String received = new String(packet.getData(), 0, packet.getLength());
return received;
}
public void close() {
socket.close();
}
}

42
core-java/src/main/java/com/baeldung/networking/udp/EchoServer.java
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@@ -1,42 +0,0 @@
package com.baeldung.networking.udp;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class EchoServer extends Thread {
protected DatagramSocket socket = null;
protected boolean running;
protected byte[] buf = new byte[256];
public EchoServer() throws IOException {
socket = new DatagramSocket(4445);
}
public void run() {
running = true;
while (running) {
try {
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
InetAddress address = packet.getAddress();
int port = packet.getPort();
packet = new DatagramPacket(buf, buf.length, address, port);
String received = new String(packet.getData(), 0, packet.getLength());
if (received.equals("end")) {
running = false;
continue;
}
socket.send(packet);
} catch (IOException e) {
e.printStackTrace();
running = false;
}
}
socket.close();
}
}

85
core-java/src/main/java/com/baeldung/networking/udp/broadcast/BroadcastingClient.java
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@@ -1,85 +0,0 @@
package com.baeldung.networking.udp.broadcast;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.NetworkInterface;
import java.net.SocketException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.stream.Collectors;
public class BroadcastingClient {
private DatagramSocket socket;
private InetAddress address;
private int expectedServerCount;
private byte[] buf;
public BroadcastingClient(int expectedServerCount) throws Exception {
this.expectedServerCount = expectedServerCount;
this.address = InetAddress.getByName("255.255.255.255");
}
public int discoverServers(String msg) throws IOException {
initializeSocketForBroadcasting();
copyMessageOnBuffer(msg);
// When we want to broadcast not just to local network, call listAllBroadcastAddresses() and execute broadcastPacket for each value.
broadcastPacket(address);
return receivePackets();
}
List<InetAddress> listAllBroadcastAddresses() throws SocketException {
List<InetAddress> broadcastList = new ArrayList<>();
Enumeration<NetworkInterface> interfaces = NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements()) {
NetworkInterface networkInterface = interfaces.nextElement();
if (networkInterface.isLoopback() || !networkInterface.isUp()) {
continue;
}
broadcastList.addAll(networkInterface.getInterfaceAddresses()
.stream()
.filter(address -> address.getBroadcast() != null)
.map(address -> address.getBroadcast())
.collect(Collectors.toList()));
}
return broadcastList;
}
private void initializeSocketForBroadcasting() throws SocketException {
socket = new DatagramSocket();
socket.setBroadcast(true);
}
private void copyMessageOnBuffer(String msg) {
buf = msg.getBytes();
}
private void broadcastPacket(InetAddress address) throws IOException {
DatagramPacket packet = new DatagramPacket(buf, buf.length, address, 4445);
socket.send(packet);
}
private int receivePackets() throws IOException {
int serversDiscovered = 0;
while (serversDiscovered != expectedServerCount) {
receivePacket();
serversDiscovered++;
}
return serversDiscovered;
}
private void receivePacket() throws IOException {
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
}
public void close() {
socket.close();
}
}

44
core-java/src/main/java/com/baeldung/networking/udp/broadcast/BroadcastingEchoServer.java
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@@ -1,44 +0,0 @@
package com.baeldung.networking.udp.broadcast;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
public class BroadcastingEchoServer extends Thread {
protected DatagramSocket socket = null;
protected boolean running;
protected byte[] buf = new byte[256];
public BroadcastingEchoServer() throws IOException {
socket = new DatagramSocket(null);
socket.setReuseAddress(true);
socket.bind(new InetSocketAddress(4445));
}
public void run() {
running = true;
while (running) {
try {
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
InetAddress address = packet.getAddress();
int port = packet.getPort();
packet = new DatagramPacket(buf, buf.length, address, port);
String received = new String(packet.getData(), 0, packet.getLength());
if (received.equals("end")) {
running = false;
continue;
}
socket.send(packet);
} catch (IOException e) {
e.printStackTrace();
running = false;
}
}
socket.close();
}
}

41
core-java/src/main/java/com/baeldung/networking/udp/multicast/MulticastEchoServer.java
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@@ -1,41 +0,0 @@
package com.baeldung.networking.udp.multicast;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.InetAddress;
import java.net.MulticastSocket;
public class MulticastEchoServer extends Thread {
protected MulticastSocket socket = null;
protected byte[] buf = new byte[256];
protected InetAddress group = null;
public MulticastEchoServer() throws IOException {
socket = new MulticastSocket(4446);
socket.setReuseAddress(true);
group = InetAddress.getByName("230.0.0.0");
socket.joinGroup(group);
}
public void run() {
try {
while (true) {
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
InetAddress address = packet.getAddress();
int port = packet.getPort();
packet = new DatagramPacket(buf, buf.length, address, port);
String received = new String(packet.getData(), 0, packet.getLength());
if (received.equals("end")) {
break;
}
socket.send(packet);
}
socket.leaveGroup(group);
socket.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

53
core-java/src/main/java/com/baeldung/networking/udp/multicast/MulticastingClient.java
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@@ -1,53 +0,0 @@
package com.baeldung.networking.udp.multicast;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
public class MulticastingClient {
private DatagramSocket socket;
private InetAddress group;
private int expectedServerCount;
private byte[] buf;
public MulticastingClient(int expectedServerCount) throws Exception {
this.expectedServerCount = expectedServerCount;
this.socket = new DatagramSocket();
this.group = InetAddress.getByName("230.0.0.0");
}
public int discoverServers(String msg) throws IOException {
copyMessageOnBuffer(msg);
multicastPacket();
return receivePackets();
}
private void copyMessageOnBuffer(String msg) {
buf = msg.getBytes();
}
private void multicastPacket() throws IOException {
DatagramPacket packet = new DatagramPacket(buf, buf.length, group, 4446);
socket.send(packet);
}
private int receivePackets() throws IOException {
int serversDiscovered = 0;
while (serversDiscovered != expectedServerCount) {
receivePacket();
serversDiscovered++;
}
return serversDiscovered;
}
private void receivePacket() throws IOException {
DatagramPacket packet = new DatagramPacket(buf, buf.length);
socket.receive(packet);
}
public void close() {
socket.close();
}
}

22
core-java/src/main/java/com/baeldung/threadlocalrandom/ThreadLocalRandomBenchMarkRunner.java
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@@ -1,22 +0,0 @@
package com.baeldung.threadlocalrandom;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;
public class ThreadLocalRandomBenchMarkRunner {
public static void main(String[] args) throws Exception {
Options options = new OptionsBuilder().include(ThreadLocalRandomBenchMarker.class.getSimpleName())
.threads(1)
.forks(1)
.shouldFailOnError(true)
.shouldDoGC(true)
.jvmArgs("-server")
.build();
new Runner(options).run();
}
}

64
core-java/src/main/java/com/baeldung/threadlocalrandom/ThreadLocalRandomBenchMarker.java
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@@ -1,64 +0,0 @@
package com.baeldung.threadlocalrandom;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;
import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Level;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Warmup;
@BenchmarkMode(Mode.AverageTime)
@Warmup(iterations = 1)
@OutputTimeUnit(TimeUnit.MICROSECONDS)
@State(Scope.Benchmark)
public class ThreadLocalRandomBenchMarker {
List<Callable<Integer>> randomCallables = new ArrayList<>();
List<Callable<Integer>> threadLocalRandomCallables = new ArrayList<>();
@Setup(Level.Iteration)
public void init() {
Random random = new Random();
randomCallables = new ArrayList<>();
threadLocalRandomCallables = new ArrayList<>();
for (int i = 0; i < 1000; i++) {
randomCallables.add(() -> {
return random.nextInt();
});
}
for (int i = 0; i < 1000; i++) {
threadLocalRandomCallables.add(() -> {
return ThreadLocalRandom.current()
.nextInt();
});
}
}
@Benchmark
public void randomValuesUsingRandom() throws InterruptedException {
ExecutorService executor = Executors.newWorkStealingPool();
executor.invokeAll(randomCallables);
executor.shutdown();
}
@Benchmark
public void randomValuesUsingThreadLocalRandom() throws InterruptedException {
ExecutorService executor = Executors.newWorkStealingPool();
executor.invokeAll(threadLocalRandomCallables);
executor.shutdown();
}
}

43
core-java/src/test/java/com/baeldung/constructorsstaticfactorymethods/UserUnitTest.java
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@@ -1,43 +0,0 @@
package com.baeldung.constructorsstaticfactorymethods;
import com.baeldung.constructorsstaticfactorymethods.entities.User;
import static org.assertj.core.api.Assertions.assertThat;
import org.junit.Test;
public class UserUnitTest {
@Test
public void givenUserClass_whenCalledcreateWithDefaultCountry_thenCorrect() {
assertThat(User.createWithDefaultCountry("John", "john@domain.com")).isInstanceOf(User.class);
}
@Test
public void givenUserIntanceCreatedWithcreateWithDefaultCountry_whenCalledgetName_thenCorrect() {
User user = User.createWithDefaultCountry("John", "john@domain.com");
assertThat(user.getName()).isEqualTo("John");
}
@Test
public void givenUserIntanceCreatedWithcreateWithDefaultCountry_whenCalledgetEmail_thenCorrect() {
User user = User.createWithDefaultCountry("John", "john@domain.com");
assertThat(user.getEmail()).isEqualTo("john@domain.com");
}
@Test
public void givenUserIntanceCreatedWithcreateWithDefaultCountry_whenCalledgetCountry_thenCorrect() {
User user = User.createWithDefaultCountry("John", "john@domain.com");
assertThat(user.getCountry()).isEqualTo("Argentina");
}
@Test
public void givenUserInstanceCreatedWithcreateWithInstantiationTime_whenCalledcreateWithInstantiationTime_thenCorrect() {
assertThat(User.createWithLoggedInstantiationTime("John", "john@domain.com", "Argentina")).isInstanceOf(User.class);
}
@Test
public void givenUserInstanceCreatedWithgetSingletonIntance_whenCalledgetSingletonInstance_thenCorrect() {
User user1 = User.getSingletonInstance("John", "john@domain.com", "Argentina");
User user2 = User.getSingletonInstance("John", "john@domain.com", "Argentina");
assertThat(user1).isEqualTo(user2);
}
}

94
core-java/src/test/java/com/baeldung/java8/Java8ForkJoinIntegrationTest.java
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@@ -1,94 +0,0 @@
package com.baeldung.java8;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import java.util.Random;
import java.util.concurrent.ForkJoinPool;
import org.junit.Before;
import org.junit.Test;
import com.baeldung.forkjoin.CustomRecursiveAction;
import com.baeldung.forkjoin.CustomRecursiveTask;
import com.baeldung.forkjoin.util.PoolUtil;
public class Java8ForkJoinIntegrationTest {
private int[] arr;
private CustomRecursiveTask customRecursiveTask;
@Before
public void init() {
Random random = new Random();
arr = new int[50];
for (int i = 0; i < arr.length; i++) {
arr[i] = random.nextInt(35);
}
customRecursiveTask = new CustomRecursiveTask(arr);
}
@Test
public void callPoolUtil_whenExistsAndExpectedType_thenCorrect() {
ForkJoinPool forkJoinPool = PoolUtil.forkJoinPool;
ForkJoinPool forkJoinPoolTwo = PoolUtil.forkJoinPool;
assertNotNull(forkJoinPool);
assertEquals(2, forkJoinPool.getParallelism());
assertEquals(forkJoinPool, forkJoinPoolTwo);
}
@Test
public void callCommonPool_whenExistsAndExpectedType_thenCorrect() {
ForkJoinPool commonPool = ForkJoinPool.commonPool();
ForkJoinPool commonPoolTwo = ForkJoinPool.commonPool();
assertNotNull(commonPool);
assertEquals(commonPool, commonPoolTwo);
}
@Test
public void executeRecursiveAction_whenExecuted_thenCorrect() {
CustomRecursiveAction myRecursiveAction = new CustomRecursiveAction("ddddffffgggghhhh");
ForkJoinPool.commonPool().invoke(myRecursiveAction);
assertTrue(myRecursiveAction.isDone());
}
@Test
public void executeRecursiveTask_whenExecuted_thenCorrect() {
ForkJoinPool forkJoinPool = ForkJoinPool.commonPool();
forkJoinPool.execute(customRecursiveTask);
int result = customRecursiveTask.join();
assertTrue(customRecursiveTask.isDone());
forkJoinPool.submit(customRecursiveTask);
int resultTwo = customRecursiveTask.join();
assertTrue(customRecursiveTask.isDone());
}
@Test
public void executeRecursiveTaskWithFJ_whenExecuted_thenCorrect() {
CustomRecursiveTask customRecursiveTaskFirst = new CustomRecursiveTask(arr);
CustomRecursiveTask customRecursiveTaskSecond = new CustomRecursiveTask(arr);
CustomRecursiveTask customRecursiveTaskLast = new CustomRecursiveTask(arr);
customRecursiveTaskFirst.fork();
customRecursiveTaskSecond.fork();
customRecursiveTaskLast.fork();
int result = 0;
result += customRecursiveTaskLast.join();
result += customRecursiveTaskSecond.join();
result += customRecursiveTaskFirst.join();
assertTrue(customRecursiveTaskFirst.isDone());
assertTrue(customRecursiveTaskSecond.isDone());
assertTrue(customRecursiveTaskLast.isDone());
assertTrue(result != 0);
}
}

38
core-java/src/test/java/com/baeldung/networking/udp/UDPLiveTest.java
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@@ -1,38 +0,0 @@
package com.baeldung.networking.udp;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.io.IOException;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
public class UDPLiveTest {
private EchoClient client;
@Before
public void setup() throws IOException {
new EchoServer().start();
client = new EchoClient();
}
@Test
public void whenCanSendAndReceivePacket_thenCorrect1() {
String echo = client.sendEcho("hello server");
assertEquals("hello server", echo);
echo = client.sendEcho("server is working");
assertFalse(echo.equals("hello server"));
}
@After
public void tearDown() {
stopEchoServer();
client.close();
}
private void stopEchoServer() {
client.sendEcho("end");
}
}

39
core-java/src/test/java/com/baeldung/networking/udp/broadcast/BroadcastLiveTest.java
View File

@@ -1,39 +0,0 @@
package com.baeldung.networking.udp.broadcast;
import org.junit.After;
import org.junit.Test;
import java.io.IOException;
import static org.junit.Assert.assertEquals;
public class BroadcastLiveTest {
private BroadcastingClient client;
@Test
public void whenBroadcasting_thenDiscoverExpectedServers() throws Exception {
int expectedServers = 4;
initializeForExpectedServers(expectedServers);
int serversDiscovered = client.discoverServers("hello server");
assertEquals(expectedServers, serversDiscovered);
}
private void initializeForExpectedServers(int expectedServers) throws Exception {
for (int i = 0; i < expectedServers; i++) {
new BroadcastingEchoServer().start();
}
client = new BroadcastingClient(expectedServers);
}
@After
public void tearDown() throws IOException {
stopEchoServer();
client.close();
}
private void stopEchoServer() throws IOException {
client.discoverServers("end");
}
}

39
core-java/src/test/java/com/baeldung/networking/udp/multicast/MulticastLiveTest.java
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@@ -1,39 +0,0 @@
package com.baeldung.networking.udp.multicast;
import org.junit.After;
import org.junit.Test;
import java.io.IOException;
import static org.junit.Assert.assertEquals;
public class MulticastLiveTest {
private MulticastingClient client;
@Test
public void whenBroadcasting_thenDiscoverExpectedServers() throws Exception {
int expectedServers = 4;
initializeForExpectedServers(expectedServers);
int serversDiscovered = client.discoverServers("hello server");
assertEquals(expectedServers, serversDiscovered);
}
private void initializeForExpectedServers(int expectedServers) throws Exception {
for (int i = 0; i < expectedServers; i++) {
new MulticastEchoServer().start();
}
client = new MulticastingClient(expectedServers);
}
@After
public void tearDown() throws IOException {
stopEchoServer();
client.close();
}
private void stopEchoServer() throws IOException {
client.discoverServers("end");
}
}

95
core-java/src/test/java/com/baeldung/thread/join/ThreadJoinUnitTest.java
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@@ -1,95 +0,0 @@
package com.baeldung.thread.join;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import java.util.logging.Logger;
import org.junit.Ignore;
import org.junit.Test;
/**
* Demonstrates Thread.join behavior.
*
*/
public class ThreadJoinUnitTest {
final static Logger LOGGER = Logger.getLogger(ThreadJoinUnitTest.class.getName());
class SampleThread extends Thread {
public int processingCount = 0;
SampleThread(int processingCount) {
this.processingCount = processingCount;
LOGGER.info("Thread " + this.getName() + " created");
}
@Override
public void run() {
LOGGER.info("Thread " + this.getName() + " started");
while (processingCount > 0) {
try {
Thread.sleep(1000); // Simulate some work being done by thread
} catch (InterruptedException e) {
LOGGER.info("Thread " + this.getName() + " interrupted.");
}
processingCount--;
LOGGER.info("Inside Thread " + this.getName() + ", processingCount = " + processingCount);
}
LOGGER.info("Thread " + this.getName() + " exiting");
}
}
@Test
public void givenNewThread_whenJoinCalled_returnsImmediately() throws InterruptedException {
Thread t1 = new SampleThread(0);
LOGGER.info("Invoking join.");
t1.join();
LOGGER.info("Returned from join");
LOGGER.info("Thread state is" + t1.getState());
assertFalse(t1.isAlive());
}
@Test
public void givenStartedThread_whenJoinCalled_waitsTillCompletion()
throws InterruptedException {
Thread t2 = new SampleThread(1);
t2.start();
LOGGER.info("Invoking join.");
t2.join();
LOGGER.info("Returned from join");
assertFalse(t2.isAlive());
}
@Test
public void givenStartedThread_whenTimedJoinCalled_waitsUntilTimedout()
throws InterruptedException {
Thread t3 = new SampleThread(10);
t3.start();
t3.join(1000);
assertTrue(t3.isAlive());
}
@Test
@Ignore
public void givenThreadTerminated_checkForEffect_notGuaranteed()
throws InterruptedException {
SampleThread t4 = new SampleThread(10);
t4.start();
//not guaranteed to stop even if t4 finishes.
do {
} while (t4.processingCount > 0);
}
@Test
public void givenJoinWithTerminatedThread_checkForEffect_guaranteed()
throws InterruptedException {
SampleThread t4 = new SampleThread(10);
t4.start();
do {
t4.join(100);
} while (t4.processingCount > 0);
}
}

63
core-java/src/test/java/com/baeldung/threadlocalrandom/ThreadLocalRandomIntegrationTest.java
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@@ -1,63 +0,0 @@
package com.baeldung.threadlocalrandom;
import java.util.concurrent.ThreadLocalRandom;
import static org.junit.Assert.assertTrue;
import org.junit.Test;
public class ThreadLocalRandomIntegrationTest {
@Test
public void givenUsingThreadLocalRandom_whenGeneratingRandomIntBounded_thenCorrect() {
int leftLimit = 1;
int rightLimit = 100;
int generatedInt = ThreadLocalRandom.current().nextInt(leftLimit, rightLimit);
assertTrue(generatedInt < rightLimit && generatedInt >= leftLimit);
}
@Test
public void givenUsingThreadLocalRandom_whenGeneratingRandomIntUnbounded_thenCorrect() {
int generatedInt = ThreadLocalRandom.current().nextInt();
assertTrue(generatedInt < Integer.MAX_VALUE && generatedInt >= Integer.MIN_VALUE);
}
@Test
public void givenUsingThreadLocalRandom_whenGeneratingRandomLongBounded_thenCorrect() {
long leftLimit = 1L;
long rightLimit = 100L;
long generatedLong = ThreadLocalRandom.current().nextLong(leftLimit, rightLimit);
assertTrue(generatedLong < rightLimit && generatedLong >= leftLimit);
}
@Test
public void givenUsingThreadLocalRandom_whenGeneratingRandomLongUnbounded_thenCorrect() {
long generatedInt = ThreadLocalRandom.current().nextLong();
assertTrue(generatedInt < Long.MAX_VALUE && generatedInt >= Long.MIN_VALUE);
}
@Test
public void givenUsingThreadLocalRandom_whenGeneratingRandomDoubleBounded_thenCorrect() {
double leftLimit = 1D;
double rightLimit = 100D;
double generatedInt = ThreadLocalRandom.current().nextDouble(leftLimit, rightLimit);
assertTrue(generatedInt < rightLimit && generatedInt >= leftLimit);
}
@Test
public void givenUsingThreadLocalRandom_whenGeneratingRandomDoubleUnbounded_thenCorrect() {
double generatedInt = ThreadLocalRandom.current().nextDouble();
assertTrue(generatedInt < Double.MAX_VALUE && generatedInt >= Double.MIN_VALUE);
}
@Test(expected = UnsupportedOperationException.class)
public void givenUsingThreadLocalRandom_whenSettingSeed_thenThrowUnsupportedOperationException() {
ThreadLocalRandom.current().setSeed(0l);
}
}