Sockets moved to core-java

core-java/src/main/java/com/baeldung/socket/EchoClient.java

@@ -0,0 +1,43 @@
+package com.baeldung.socket;
+
+import java.io.*;
+import java.net.*;
+
+public class EchoClient {
+	private Socket clientSocket;
+	private PrintWriter out;
+	private BufferedReader in;
+
+	public void startConnection(String ip, int port) {
+		try {
+			clientSocket = new Socket(ip, port);
+			out = new PrintWriter(clientSocket.getOutputStream(), true);
+			in = new BufferedReader(new InputStreamReader(
+					clientSocket.getInputStream()));
+		} catch (IOException e) {
+			System.out.print(e);
+		}
+
+	}
+
+	public String sendMessage(String msg) {
+		try {
+			out.println(msg);
+			String resp = in.readLine();
+			return resp;
+		} catch (Exception e) {
+			return null;
+		}
+	}
+
+	public void stopConnection() {
+		try {
+			in.close();
+			out.close();
+			clientSocket.close();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+
+	}
+}

core-java/src/main/java/com/baeldung/socket/EchoMultiServer.java

@@ -0,0 +1,71 @@
+package com.baeldung.socket;
+
+import java.net.*;
+import java.io.*;
+
+public class EchoMultiServer {
+	private ServerSocket serverSocket;
+
+	public void start(int port) {
+		try {
+			serverSocket = new ServerSocket(port);
+			while (true)
+				new EchoClientHandler(serverSocket.accept()).run();
+
+		} catch (IOException e) {
+			e.printStackTrace();
+		} finally {
+			stop();
+		}
+
+	}
+
+	public void stop() {
+		try {
+
+			serverSocket.close();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+
+	}
+
+	private static class EchoClientHandler extends Thread {
+		private Socket clientSocket;
+		private PrintWriter out;
+		private BufferedReader in;
+
+		public EchoClientHandler(Socket socket) {
+			this.clientSocket = socket;
+		}
+
+		public void run() {
+			try {
+				out = new PrintWriter(clientSocket.getOutputStream(), true);
+				in = new BufferedReader(new InputStreamReader(
+						clientSocket.getInputStream()));
+				String inputLine;
+				while ((inputLine = in.readLine()) != null) {
+					if ("".equals(inputLine)) {
+						out.println("bye");
+						break;
+					}
+					out.println(inputLine);
+				}
+
+				in.close();
+				out.close();
+				clientSocket.close();
+
+			} catch (IOException e) {
+				e.printStackTrace();
+			}
+		}
+	}
+
+	public static void main(String[] args) {
+		EchoMultiServer server = new EchoMultiServer();
+		server.start(5555);
+	}
+
+}

core-java/src/main/java/com/baeldung/socket/EchoServer.java

@@ -0,0 +1,50 @@
+package com.baeldung.socket;
+
+import java.net.*;
+import java.io.*;
+
+public class EchoServer {
+	private ServerSocket serverSocket;
+	private Socket clientSocket;
+	private PrintWriter out;
+	private BufferedReader in;
+
+	public void start(int port) {
+		try {
+			serverSocket = new ServerSocket(port);
+			clientSocket = serverSocket.accept();
+			out = new PrintWriter(clientSocket.getOutputStream(), true);
+			in = new BufferedReader(new InputStreamReader(
+					clientSocket.getInputStream()));
+			String inputLine;
+			while ((inputLine = in.readLine()) != null) {
+				if ("".equals(inputLine)) {
+					out.println("good bye");
+					break;
+				}
+				out.println(inputLine);
+			}
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+
+	}
+
+	public void stop() {
+		try {
+			in.close();
+			out.close();
+			clientSocket.close();
+			serverSocket.close();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+
+	}
+
+	public static void main(String[] args) {
+		EchoServer server = new EchoServer();
+		server.start(4444);
+	}
+
+}

core-java/src/main/java/com/baeldung/socket/GreetClient.java

@@ -0,0 +1,46 @@
+package com.baeldung.socket;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.Socket;
+
+public class GreetClient {
+	private Socket clientSocket;
+	private PrintWriter out;
+	private BufferedReader in;
+
+	public void startConnection(String ip, int port) {
+		try {
+			clientSocket = new Socket(ip, port);
+			out = new PrintWriter(clientSocket.getOutputStream(), true);
+			in = new BufferedReader(new InputStreamReader(
+					clientSocket.getInputStream()));
+		} catch (IOException e) {
+			
+		}
+
+	}
+
+	public String sendMessage(String msg) {
+		try {
+			out.println(msg);
+			String resp = in.readLine();
+			return resp;
+		} catch (Exception e) {
+			return null;
+		}
+	}
+
+	public void stopConnection() {
+		try {
+			in.close();
+			out.close();
+			clientSocket.close();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+
+}

core-java/src/main/java/com/baeldung/socket/GreetServer.java

@@ -0,0 +1,47 @@
+package com.baeldung.socket;
+
+import java.net.*;
+import java.io.*;
+
+public class GreetServer {
+	private ServerSocket serverSocket;
+	private Socket clientSocket;
+	private PrintWriter out;
+	private BufferedReader in;
+
+
+	public void start(int port) {
+		try {
+			serverSocket = new ServerSocket(port);
+			clientSocket = serverSocket.accept();
+			out = new PrintWriter(clientSocket.getOutputStream(), true);
+			in = new BufferedReader(new InputStreamReader(
+					clientSocket.getInputStream()));
+			String greeting = in.readLine();
+			if ("hello server".equals(greeting))
+				out.println("hello client");
+			else
+				out.println("unrecognised greeting");
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+
+	}
+
+	public void stop() {
+		try {
+			in.close();
+			out.close();
+			clientSocket.close();
+			serverSocket.close();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+
+	}
+	public static void main(String[] args) {
+		GreetServer server=new GreetServer();
+		server.start(6666);
+	}
+
+}