Merge branch 'eugenp:master' into master

core-java-modules/core-java-networking-3/src/main/java/com/baeldung/clientaddress/ApplicationClient.java

@@ -0,0 +1,39 @@
+package com.baeldung.clientaddress;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.Socket;
+
+public class ApplicationClient {
+
+    private Socket clientSocket;
+    private PrintWriter out;
+    private BufferedReader in;
+
+    public void connect(String ip, int port) throws IOException {
+        clientSocket = new Socket(ip, port);
+        out = new PrintWriter(clientSocket.getOutputStream(), true);
+        in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
+    }
+
+    public void sendGreetings(String msg) throws IOException {
+        out.println(msg);
+        String reply = in.readLine();
+        System.out.println("Reply received from the server :: " + reply);
+    }
+
+    public void disconnect() throws IOException {
+        in.close();
+        out.close();
+        clientSocket.close();
+    }
+
+    public static void main(String[] args) throws IOException {
+        ApplicationClient client = new ApplicationClient();
+        client.connect(args[0], Integer.parseInt(args[1])); // IP address and port number of the server
+        client.sendGreetings(args[2]); // greetings message
+        client.disconnect();
+    }
+}

core-java-modules/core-java-networking-3/src/main/java/com/baeldung/clientaddress/ApplicationServer.java

@@ -0,0 +1,51 @@
+package com.baeldung.clientaddress;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.InetSocketAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+public class ApplicationServer {
+
+    private ServerSocket serverSocket;
+    private Socket connectedSocket;
+    private PrintWriter out;
+    private BufferedReader in;
+
+    public void startServer(int port) throws IOException {
+        serverSocket = new ServerSocket(port);
+        connectedSocket = serverSocket.accept();
+
+        InetSocketAddress socketAddress = (InetSocketAddress) connectedSocket.getRemoteSocketAddress();
+        String clientIpAddress = socketAddress.getAddress()
+            .getHostAddress();
+        System.out.println("IP address of the connected client :: " + clientIpAddress);
+
+        out = new PrintWriter(connectedSocket.getOutputStream(), true);
+        in = new BufferedReader(new InputStreamReader(connectedSocket.getInputStream()));
+        String msg = in.readLine();
+        System.out.println("Message received from the client :: " + msg);
+        out.println("Hello Client !!");
+
+        closeIO();
+        stopServer();
+    }
+
+    private void closeIO() throws IOException {
+        in.close();
+        out.close();
+    }
+
+    private void stopServer() throws IOException {
+        connectedSocket.close();
+        serverSocket.close();
+    }
+
+    public static void main(String[] args) throws IOException {
+        ApplicationServer server = new ApplicationServer();
+        server.startServer(5000);
+    }
+}

core-java-modules/core-java-os/src/main/java/com/baeldung/java9/process/ProcessAPIEnhancements.java

@@ -0,0 +1,101 @@
+package com.baeldung.java9.process;
+
+import java.io.IOException;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ExecutionException;
+import java.util.stream.Stream;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ProcessAPIEnhancements {
+
+    static Logger log = LoggerFactory.getLogger(ProcessAPIEnhancements.class);
+
+    public static void main(String[] args) throws IOException, InterruptedException, ExecutionException {
+        infoOfCurrentProcess();
+        infoOfLiveProcesses();
+        infoOfSpawnProcess();
+        infoOfExitCallback();
+        infoOfChildProcess();
+    }
+
+    private static void infoOfCurrentProcess() {
+        ProcessHandle processHandle = ProcessHandle.current();
+        ProcessHandle.Info processInfo = processHandle.info();
+
+        log.info("PID: " + processHandle.pid());
+        log.info("Arguments: " + processInfo.arguments());
+        log.info("Command: " + processInfo.command());
+        log.info("Instant: " + processInfo.startInstant());
+        log.info("Total CPU duration: " + processInfo.totalCpuDuration());
+        log.info("User: " + processInfo.user());
+    }
+
+    private static void infoOfSpawnProcess() throws IOException {
+
+        String javaCmd = ProcessUtils.getJavaCmd().getAbsolutePath();
+        ProcessBuilder processBuilder = new ProcessBuilder(javaCmd, "-version");
+        Process process = processBuilder.inheritIO().start();
+        ProcessHandle processHandle = process.toHandle();
+        ProcessHandle.Info processInfo = processHandle.info();
+
+        log.info("PID: " + processHandle.pid());
+        log.info("Arguments: " + processInfo.arguments());
+        log.info("Command: " + processInfo.command());
+        log.info("Instant: " + processInfo.startInstant());
+        log.info("Total CPU duration: " + processInfo.totalCpuDuration());
+        log.info("User: " + processInfo.user());
+    }
+
+    private static void infoOfLiveProcesses() {
+        Stream<ProcessHandle> liveProcesses = ProcessHandle.allProcesses();
+        liveProcesses.filter(ProcessHandle::isAlive)
+            .forEach(ph -> {
+                log.info("PID: " + ph.pid());
+                log.info("Instance: " + ph.info().startInstant());
+                log.info("User: " + ph.info().user());
+            });
+    }
+
+    private static void infoOfChildProcess() throws IOException {
+        int childProcessCount = 5;
+        for (int i = 0; i < childProcessCount; i++) {
+            String javaCmd = ProcessUtils.getJavaCmd()
+              .getAbsolutePath();
+            ProcessBuilder processBuilder
+              = new ProcessBuilder(javaCmd, "-version");
+            processBuilder.inheritIO().start();
+        }
+
+        Stream<ProcessHandle> children = ProcessHandle.current()
+          .children();
+        children.filter(ProcessHandle::isAlive)
+          .forEach(ph -> log.info("PID: {}, Cmd: {}", ph.pid(), ph.info()
+            .command()));
+        Stream<ProcessHandle> descendants = ProcessHandle.current()
+          .descendants();
+        descendants.filter(ProcessHandle::isAlive)
+          .forEach(ph -> log.info("PID: {}, Cmd: {}", ph.pid(), ph.info()
+            .command()));
+    }
+
+    private static void infoOfExitCallback() throws IOException, InterruptedException, ExecutionException {
+        String javaCmd = ProcessUtils.getJavaCmd()
+          .getAbsolutePath();
+        ProcessBuilder processBuilder
+          = new ProcessBuilder(javaCmd, "-version");
+        Process process = processBuilder.inheritIO()
+          .start();
+        ProcessHandle processHandle = process.toHandle();
+
+        log.info("PID: {} has started", processHandle.pid());
+        CompletableFuture<ProcessHandle> onProcessExit = processHandle.onExit();
+        onProcessExit.get();
+        log.info("Alive: " + processHandle.isAlive());
+        onProcessExit.thenAccept(ph -> {
+            log.info("PID: {} has stopped", ph.pid());
+        });
+    }
+
+}

core-java-modules/core-java-os/src/test/java/com/baeldung/java9/process/ProcessAPIEnhancementsUnitTest.java

@@ -1,132 +0,0 @@
-package com.baeldung.java9.process;
-
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertNotNull;
-import static org.junit.Assert.assertTrue;
-
-import java.io.IOException;
-import java.util.concurrent.CompletableFuture;
-import java.util.stream.Stream;
-
-import org.junit.Test;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-/**
- * Created by sanaulla on 2/23/2017.
- */
-
-public class ProcessAPIEnhancementsUnitTest {
-
-    Logger log = LoggerFactory.getLogger(ProcessAPIEnhancementsUnitTest.class);
-
-    // @Test
-    // OS / Java version dependent
-    public void givenCurrentProcess_whenInvokeGetInfo_thenSuccess() throws IOException {
-        ProcessHandle processHandle = ProcessHandle.current();
-        ProcessHandle.Info processInfo = processHandle.info();
-        assertNotNull(processHandle.pid());
-        assertEquals(true, processInfo.arguments()
-          .isPresent());
-        assertEquals(true, processInfo.command()
-          .isPresent());
-        assertTrue(processInfo.command()
-          .get()
-          .contains("java"));
-
-        assertEquals(true, processInfo.startInstant()
-          .isPresent());
-        assertEquals(true, processInfo.totalCpuDuration()
-          .isPresent());
-        assertEquals(true, processInfo.user()
-          .isPresent());
-    }
-
-    // @Test
-    // OS / Java version dependent
-    public void givenSpawnProcess_whenInvokeGetInfo_thenSuccess() throws IOException {
-
-        String javaCmd = ProcessUtils.getJavaCmd()
-          .getAbsolutePath();
-        ProcessBuilder processBuilder = new ProcessBuilder(javaCmd, "-version");
-        Process process = processBuilder.inheritIO()
-          .start();
-        ProcessHandle processHandle = process.toHandle();
-        ProcessHandle.Info processInfo = processHandle.info();
-        assertNotNull(processHandle.pid());
-        assertEquals(true, processInfo.arguments()
-          .isPresent());
-        assertEquals(true, processInfo.command()
-          .isPresent());
-        assertTrue(processInfo.command()
-          .get()
-          .contains("java"));
-        assertEquals(true, processInfo.startInstant()
-          .isPresent());
-        assertEquals(false, processInfo.totalCpuDuration()
-          .isPresent());
-        assertEquals(true, processInfo.user()
-          .isPresent());
-    }
-
-    // @Test
-    // OS / Java version dependent
-    public void givenLiveProcesses_whenInvokeGetInfo_thenSuccess() {
-        Stream<ProcessHandle> liveProcesses = ProcessHandle.allProcesses();
-        liveProcesses.filter(ProcessHandle::isAlive)
-            .forEach(ph -> {
-                assertNotNull(ph.pid());
-                assertEquals(true, ph.info()
-                  .startInstant()
-                  .isPresent());
-                assertEquals(true, ph.info()
-                  .user()
-                  .isPresent());
-            });
-    }
-
-    // @Test
-    // OS / Java version dependent
-    public void givenProcess_whenGetChildProcess_thenSuccess() throws IOException {
-        int childProcessCount = 5;
-        for (int i = 0; i < childProcessCount; i++) {
-            String javaCmd = ProcessUtils.getJavaCmd()
-              .getAbsolutePath();
-            ProcessBuilder processBuilder
-              = new ProcessBuilder(javaCmd, "-version");
-            processBuilder.inheritIO().start();
-        }
-
-        Stream<ProcessHandle> children = ProcessHandle.current()
-          .children();
-        children.filter(ProcessHandle::isAlive)
-          .forEach(ph -> log.info("PID: {}, Cmd: {}", ph.pid(), ph.info()
-            .command()));
-        Stream<ProcessHandle> descendants = ProcessHandle.current()
-          .descendants();
-        descendants.filter(ProcessHandle::isAlive)
-          .forEach(ph -> log.info("PID: {}, Cmd: {}", ph.pid(), ph.info()
-            .command()));
-    }
-
-    // @Test
-    // OS / Java version dependent
-    public void givenProcess_whenAddExitCallback_thenSuccess() throws Exception {
-        String javaCmd = ProcessUtils.getJavaCmd()
-          .getAbsolutePath();
-        ProcessBuilder processBuilder
-          = new ProcessBuilder(javaCmd, "-version");
-        Process process = processBuilder.inheritIO()
-          .start();
-        ProcessHandle processHandle = process.toHandle();
-
-        log.info("PID: {} has started", processHandle.pid());
-        CompletableFuture<ProcessHandle> onProcessExit = processHandle.onExit();
-        onProcessExit.get();
-        assertEquals(false, processHandle.isAlive());
-        onProcessExit.thenAccept(ph -> {
-            log.info("PID: {} has stopped", ph.pid());
-        });
-    }
-
-}

maven-modules/maven-parent-pom-resolution/aggregator/module1/pom.xml

@@ -3,11 +3,11 @@
     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>project-b</artifactId>
+    <artifactId>module1</artifactId>
     <parent>
-        <groupId>com.baeldung</groupId>
+        <groupId>com.baeldung.maven-parent-pom-resolution</groupId>
-        <artifactId>project-a</artifactId>
+        <artifactId>aggregator</artifactId>
-        <version>1.0-SNAPSHOT</version>
+        <version>1.0.0-SNAPSHOT</version>
         <!-- The parent pom is resolved to project a's pom.xml -->
     </parent>
     <packaging>pom</packaging>

maven-modules/maven-parent-pom-resolution/aggregator/module2/module3/pom.xml

@@ -3,11 +3,11 @@
     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>project-d</artifactId>
+    <artifactId>module3</artifactId>
     <parent>
-        <groupId>com.baeldung</groupId>
+        <groupId>com.baeldung.maven-parent-pom-resolution</groupId>
-        <artifactId>project-a</artifactId>
+        <artifactId>aggregator</artifactId>
-        <version>1.0-SNAPSHOT</version>
+        <version>1.0.0-SNAPSHOT</version>
         <!-- removing relativePath won't work even if project-a is the aggregator project -->
         <!-- it only works in IntelliJ IDEA when project-a is registered as a Maven Project -->
         <relativePath>../../pom.xml</relativePath>

maven-modules/maven-parent-pom-resolution/aggregator/module2/pom.xml

@@ -3,18 +3,18 @@
     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>project-c</artifactId>
+    <artifactId>module2</artifactId>
     <parent>
-        <groupId>com.baeldung</groupId>
+        <groupId>com.baeldung.maven-parent-pom-resolution</groupId>
-        <artifactId>project-b</artifactId>
+        <artifactId>module1</artifactId>
-        <version>1.0-SNAPSHOT</version>
+        <version>1.0.0-SNAPSHOT</version>
-        <relativePath>../project-b/pom.xml</relativePath>
+        <relativePath>../module1/pom.xml</relativePath>
         <!-- The parent pom is resolved to project a's pom.xml -->
     </parent>
     <packaging>pom</packaging>
 
     <modules>
-        <module>project-d</module>
+        <module>module3</module>
     </modules>
 
 </project>

maven-modules/maven-parent-pom-resolution/aggregator/pom.xml

@@ -3,18 +3,19 @@
     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>project-a</artifactId>
+    <groupId>com.baeldung.maven-parent-pom-resolution</groupId>
+    <artifactId>aggregator</artifactId>
     <parent>
         <groupId>com.baeldung</groupId>
         <artifactId>maven-parent-pom-resolution</artifactId>
-        <version>1.0-SNAPSHOT</version>
+        <version>1.0.0-SNAPSHOT</version>
         <!-- The parent pom is resolved to ../pom.xml -->
     </parent>
     <packaging>pom</packaging>
 
     <modules>
-        <module>project-b</module>
+        <module>module1</module>
-        <module>project-c</module>
+        <module>module2</module>
     </modules>
 
 </project>

maven-modules/maven-parent-pom-resolution/pom.xml

@@ -5,11 +5,11 @@
     <modelVersion>4.0.0</modelVersion>
     <groupId>com.baeldung</groupId>
     <artifactId>maven-parent-pom-resolution</artifactId>
-    <version>1.0-SNAPSHOT</version>
+    <version>1.0.0-SNAPSHOT</version>
     <packaging>pom</packaging>
 
     <modules>
-        <module>project-a</module>
+        <module>aggregator</module>
     </modules>
 
     <!-- to detect the POM hierarchy, just type "mvn dependency:display-ancestors" -->

persistence-modules/spring-data-mongodb-reactive/README.md

@@ -8,5 +8,3 @@ The "REST With Spring" Classes: http://bit.ly/restwithspring
 ### Relevant Articles
 - [Spring Data Reactive Repositories with MongoDB](https://www.baeldung.com/spring-data-mongodb-reactive)
 - [Spring Data MongoDB Tailable Cursors](https://www.baeldung.com/spring-data-mongodb-tailable-cursors)
-- [A Quick Look at R2DBC with Spring Data](https://www.baeldung.com/spring-data-r2dbc)
-- [Spring Data Reactive Repositories with Couchbase](https://www.baeldung.com/spring-data-reactive-couchbase)

spring-5-data-reactive/README.md

@@ -6,7 +6,5 @@ This module contains articles about reactive Spring 5 Data
 The "REST With Spring" Classes: http://bit.ly/restwithspring
 
 ### Relevant Articles
-- [Spring Data Reactive Repositories with MongoDB](https://www.baeldung.com/spring-data-mongodb-reactive)
-- [Spring Data MongoDB Tailable Cursors](https://www.baeldung.com/spring-data-mongodb-tailable-cursors)
 - [A Quick Look at R2DBC with Spring Data](https://www.baeldung.com/spring-data-r2dbc)
 - [Spring Data Reactive Repositories with Couchbase](https://www.baeldung.com/spring-data-reactive-couchbase)

spring-websockets/src/main/java/com/baeldung/rawwebsocket/ServerWebSocketConfig.java

@@ -0,0 +1,23 @@
+package com.baeldung.rawwebsocket;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.socket.WebSocketHandler;
+import org.springframework.web.socket.config.annotation.EnableWebSocket;
+import org.springframework.web.socket.config.annotation.WebSocketConfigurer;
+import org.springframework.web.socket.config.annotation.WebSocketHandlerRegistry;
+
+@Configuration
+@EnableWebSocket
+public class ServerWebSocketConfig implements WebSocketConfigurer {
+    
+    @Override
+    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
+        registry.addHandler(webSocketHandler(), "/websocket");
+    }
+    
+    @Bean
+    public WebSocketHandler webSocketHandler() {
+        return new ServerWebSocketHandler();
+    }
+}

spring-websockets/src/main/java/com/baeldung/rawwebsocket/ServerWebSocketHandler.java

@@ -0,0 +1,72 @@
+package com.baeldung.rawwebsocket;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.scheduling.annotation.Scheduled;
+import org.springframework.web.socket.CloseStatus;
+import org.springframework.web.socket.SubProtocolCapable;
+import org.springframework.web.socket.TextMessage;
+import org.springframework.web.socket.WebSocketSession;
+import org.springframework.web.socket.handler.TextWebSocketHandler;
+import org.springframework.web.util.HtmlUtils;
+
+import java.io.IOException;
+import java.time.LocalTime;
+import java.util.Collections;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.CopyOnWriteArraySet;
+
+public class ServerWebSocketHandler extends TextWebSocketHandler implements SubProtocolCapable {
+    
+    private static final Logger logger = LoggerFactory.getLogger(ServerWebSocketHandler.class);
+    
+    private final Set<WebSocketSession> sessions = new CopyOnWriteArraySet<>();
+    
+    @Override
+    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
+        logger.info("Server connection opened");
+        sessions.add(session);
+        
+        TextMessage message = new TextMessage("one-time message from server");
+        logger.info("Server sends: {}", message);
+        session.sendMessage(message);
+    }
+    
+    @Override
+    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) {
+        logger.info("Server connection closed: {}", status);
+        sessions.remove(session);
+    }
+    
+    @Scheduled(fixedRate = 10000)
+    void sendPeriodicMessages() throws IOException {
+        for (WebSocketSession session : sessions) {
+            if (session.isOpen()) {
+                String broadcast = "server periodic message " + LocalTime.now();
+                logger.info("Server sends: {}", broadcast);
+                session.sendMessage(new TextMessage(broadcast));
+            }
+        }
+    }
+    
+    @Override
+    public void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
+        String request = message.getPayload();
+        logger.info("Server received: {}", request);
+        
+        String response = String.format("response from server to '%s'", HtmlUtils.htmlEscape(request));
+        logger.info("Server sends: {}", response);
+        session.sendMessage(new TextMessage(response));
+    }
+    
+    @Override
+    public void handleTransportError(WebSocketSession session, Throwable exception) {
+        logger.info("Server transport error: {}", exception.getMessage());
+    }
+    
+    @Override
+    public List<String> getSubProtocols() {
+        return Collections.singletonList("subprotocol.demo.websocket");
+    }
+}