socket ( java ) 简单多个客户端、服务端通信（多线程）
原创作品，允许转载，转载时请务必以超链接形式标明文章 原始出处 、作者信息和本声明。否则将追究法律责任。http://blog.csdn.net/love254443233/article/details/7897269

实现:

客户端：多个socket（多个端口），其中一个客户端的一个端口用于接收服务端发送过来的消息，其一个用于向服务端发送消息。其它客户端只有发消息的功能。

服务端：两个socket，一个用于循环接收客户端发送过来的socket请求。一个用于接收消息手自动向客户端发送消息。

注：先运行MySocketServer，然后MySocketClient，最后SocketClient；MySocketClient、SocketClient向MySocketServer发送消息。

1、MySocketServer类：

package socket._5;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import java.net.ServerSocket;import java.net.Socket;public class MySocketServer {private static int localHostPort = 5000;public static void main(String[] args) throws IOException {ServerSocket s = new ServerSocket(localHostPort);System.out.println("服务器端------监听中.....");while (true) {Socket socket = s.accept();System.out.println("接入的socket：" + socket);GetMessage getMessage = new GetMessage(socket);Thread thread = new Thread(getMessage);thread.start();}}}// 接收消息class GetMessage implements Runnable {private int remotePort = 5001;private String remoetAddress = "localhost";private InputStream inputStream;private OutputStream outputStream;private Socket socketGet;private Socket socketSendMessage;private boolean socketIsExits = false;private int sum = 0;private byte[] buffer;public GetMessage(Socket socket) {this.socketGet = socket;try {inputStream = socketGet.getInputStream();outputStream = socketGet.getOutputStream();} catch (IOException e) {e.printStackTrace();}}public void run() {String str = "";int n = 0;while (true) {try {buffer = new byte[2048];n = inputStream.read(buffer);str = new String(buffer, 0, n);System.out.print("客户端:" + str);sendMessage();} catch (IOException e) {e.printStackTrace();break;}if (str.equals("q")) {break;}}try {if (socketGet != null)socketGet.close();if (inputStream != null)inputStream.close();} catch (Exception e) {}}// 发送消息public void sendMessage() throws IOException {if (socketIsExits) {try {String input = "======" + (sum++);System.out.println("服务端发送 socket：" + this.socketSendMessage);outputStream.write(input.getBytes());System.out.println("服务器：" + input);outputStream.flush();} catch (Exception e) {System.out.println("客户端socket不存在。");checkSocket();}} else {checkSocket();}}private void checkSocket() {try {socketSendMessage = new Socket(remoetAddress, remotePort);outputStream = socketSendMessage.getOutputStream();socketIsExits = true;} catch (Exception e) {socketIsExits = false;}}}

package socket._5;import java.io.*;import java.net.*;public class MySocketClient {private static int localHostPort = 5001;public static void main(String[] args) throws IOException {CSendMessage cSendMessage = new CSendMessage();Thread thread2 = new Thread(cSendMessage);thread2.start();ServerSocket serverSocket = new ServerSocket(localHostPort);while (true) {Socket socketServer = serverSocket.accept();CGetMessage getMessage = new CGetMessage(socketServer);Thread thread = new Thread(getMessage);thread.start();}}}// 接收消息class CGetMessage implements Runnable {private InputStream inputStream;private Socket socket;private byte[] buffer;public CGetMessage(Socket socket) {this.socket = socket;try {inputStream = socket.getInputStream();} catch (IOException e) {e.printStackTrace();}}public void run() {String str = "";while (true) {buffer = new byte[2048];int n = 0;try {n = inputStream.read(buffer);str = new String(buffer, 0, n);System.out.println("服务器:" + str);} catch (IOException e) {e.printStackTrace();break;}if (str.equals("q")) {break;}}try {if (socket != null)socket.close();if (inputStream != null)inputStream.close();} catch (Exception e) {}}}// 发送消息class CSendMessage implements Runnable {private boolean socketIsExits = false;private OutputStream outputStream;private Socket socketClient;private int remotePort = 5000;private String remoteAddress = "localhost";private byte[] buffer;public CSendMessage() throws IOException {}public void run() {String str = new String();checkSocket();int size = 0;while (true) {try {System.out.println("请输入:");buffer = new byte[2048];size = System.in.read(buffer);str = new String(buffer, 0, size);} catch (IOException e) {e.printStackTrace();}if (socketIsExits) {try {System.out.println("客户端发送 socket：" + this.socketClient);System.out.print("客户端:" + str);outputStream.write(str.getBytes());outputStream.flush();} catch (Exception e) {System.out.println("客户端socket不存在。");checkSocket();}} else {checkSocket();}}}private void checkSocket() {try {socketClient = new Socket(remoteAddress, remotePort);outputStream = socketClient.getOutputStream();socketIsExits = true;} catch (Exception e) {socketIsExits = false;}}}

package socket._5;import java.io.IOException;import java.io.OutputStream;import java.net.Socket;import java.net.UnknownHostException;public class SocketClient implements Runnable {public int remotePort = 5000;public String remoteAddress = "localhost";public static void main(String args[]) {SocketClient socketClient = new SocketClient();socketClient.run();}public SocketClient() {}public void run() {Socket socket = null;OutputStream outputStream = null;byte[] buffer;int size = 0;try {socket = new Socket(remoteAddress, remotePort);outputStream = socket.getOutputStream();System.out.println(socket);while (true) {System.out.println("input:");buffer = new byte[2048];size = System.in.read(buffer);if (size > 0) {outputStream.write(new String(buffer, 0, size).getBytes());outputStream.flush();}}} catch (UnknownHostException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();} finally {try {if (socket != null)socket.close();if (outputStream != null)outputStream.close();} catch (IOException e) {e.printStackTrace();}}}}