BAEL-7218: Inter-Process Communication Methods in Java (#15286)

core-java-modules/core-java-ipc/pom.xml

@@ -0,0 +1,16 @@
+<?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-java-ipc</artifactId>
+    <name>core-java-ipc</name>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung.core-java-modules</groupId>
+        <artifactId>core-java-modules</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+    </parent>
+
+</project>

core-java-modules/core-java-ipc/src/test/java/com/baeldung/ipc/DirectoryLiveTest.java

@@ -0,0 +1,32 @@
+package com.baeldung.ipc;
+
+import org.junit.jupiter.api.Test;
+
+import java.nio.file.FileSystems;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.nio.file.StandardWatchEventKinds;
+import java.nio.file.WatchKey;
+import java.nio.file.WatchEvent;
+import java.nio.file.WatchService;
+
+
+public class DirectoryLiveTest {
+    @Test
+    public void consumer() throws Exception {
+        WatchService watchService = FileSystems.getDefault().newWatchService();
+        // Set this to an appropriate directory.
+        Path path = Paths.get("/tmp/ipc");
+
+        path.register(watchService, StandardWatchEventKinds.ENTRY_CREATE);
+
+        WatchKey key;
+        while ((key = watchService.take()) != null) {
+            for (WatchEvent<?> event : key.pollEvents()) {
+                // React to new file.
+                System.out.println(event);
+            }
+            key.reset();
+        }
+    }
+}

core-java-modules/core-java-ipc/src/test/java/com/baeldung/ipc/JmxLiveTest.java

@@ -0,0 +1,52 @@
+package com.baeldung.ipc;
+
+import org.junit.jupiter.api.Test;
+
+import javax.management.JMX;
+import javax.management.MBeanServer;
+import javax.management.ObjectName;
+import javax.management.remote.JMXConnector;
+import javax.management.remote.JMXConnectorFactory;
+import javax.management.remote.JMXServiceURL;
+import java.lang.management.ManagementFactory;
+import java.util.concurrent.TimeUnit;
+
+public class JmxLiveTest {
+    /*
+     * This test needs to be run with the following system properties defined:
+     * -Dcom.sun.management.jmxremote=true
+     * -Dcom.sun.management.jmxremote.port=1234
+     * -Dcom.sun.management.jmxremote.authenticate=false
+     * -Dcom.sun.management.jmxremote.ssl=false
+     */
+    @Test
+    public void consumer() throws Exception {
+        ObjectName objectName = new ObjectName("com.baeldung.ipc:type=basic,name=test");
+        MBeanServer server = ManagementFactory.getPlatformMBeanServer();
+        server.registerMBean(new IPCTest(), objectName);
+
+        TimeUnit.MINUTES.sleep(50);
+    }
+
+    @Test
+    public void producer() throws Exception {
+        JMXServiceURL url = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://localhost:1234/jmxrmi");
+        try (JMXConnector jmxc = JMXConnectorFactory.connect(url, null)) {
+            ObjectName objectName = new ObjectName("com.baeldung.ipc:type=basic,name=test");
+
+            IPCTestMBean mbeanProxy = JMX.newMBeanProxy(jmxc.getMBeanServerConnection(), objectName, IPCTestMBean.class, true);
+            mbeanProxy.sendMessage("Hello");
+        }
+    }
+
+    public interface IPCTestMBean {
+        void sendMessage(String message);
+    }
+
+    class IPCTest implements IPCTestMBean {
+        @Override
+        public void sendMessage(String message) {
+            System.out.println("Received message: " + message);
+        }
+    }
+}

core-java-modules/core-java-ipc/src/test/java/com/baeldung/ipc/SocketsLiveTest.java

@@ -0,0 +1,38 @@
+package com.baeldung.ipc;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.BufferedReader;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+public class SocketsLiveTest {
+    @Test
+    public void consumer() throws Exception {
+        try (ServerSocket serverSocket = new ServerSocket(1234)) {
+            Socket clientSocket = serverSocket.accept();
+
+            PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
+            BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
+
+            String line;
+            while ((line = in.readLine()) != null) {
+                System.out.println("Received message: " + line);
+            }
+        }
+    }
+
+    @Test
+    public void producer() throws Exception {
+        try (Socket clientSocket = new Socket("localhost", 1234)) {
+            PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
+            BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
+
+            out.println("Hello");
+            
+            String response = in.readLine();
+        }
+    }
+}

core-java-modules/pom.xml

@@ -54,6 +54,7 @@
         <module>core-java-concurrency-simple</module>
         <module>core-java-datetime-string</module>
         <module>core-java-io-conversions-2</module>
+        <module>core-java-ipc</module>
         <module>core-java-jpms</module>
         <module>core-java-lang-oop-constructors-2</module>
         <module>core-java-methods</module>