一個用Java寫的簡單的TCP聊天程序

原文地址：http://blog.csdn.net/yubo_725/article/details/45331487   感謝作者分享。

服務端代碼：

package com.test.server;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {

    public static void main(String[] args) {
        new Server().startServer();
    }

    public void startServer(){
        try {
            //服務器在9990端口監聽客戶端的連接
            ServerSocket ss = new ServerSocket(9999);
            System.out.println("server is listening...");
            while(true){
                //阻塞的accept方法，當一個客戶端連接上，纔會返回Socket對象
                Socket s = ss.accept();
                System.out.println("a client has connected!");
                //開啓線程處理通信
                new CommunicateThread(s).start();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public class CommunicateThread extends Thread{

        Socket socket;
        DataInputStream dis;
        DataOutputStream dos;

        public CommunicateThread(Socket socket){
            this.socket = socket;
            try {
                dis = new DataInputStream(socket.getInputStream());
                dos = new DataOutputStream(socket.getOutputStream());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        @Override
        public void run() {
            super.run();
            //讀取客戶端發過來的消息
            String msg = null;
            try {
                while((msg = dis.readUTF()) != null){
                    System.out.println("client send msg ：" + msg);
                    String replyMsg = "server reply ： " + msg;
                    dos.writeUTF(replyMsg);
                    System.out.println("server reply msg ：" + replyMsg);
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}

客戶端代碼：

package com.test.client;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.Socket;
import java.util.Scanner;

public class Client {

    public static void main(String[] args) {
        new Client().startClient();
    }

    public void startClient(){
        try {
            //連接到服務器
            Socket socket = new Socket("localhost", 9999);
            DataInputStream dis = new DataInputStream(socket.getInputStream());
            DataOutputStream dos = new DataOutputStream(socket.getOutputStream());
            Scanner scanner = new Scanner(System.in);
            String line = null;
            listenServerReply(dis);
            while((line = scanner.nextLine()) != null){//讀取從鍵盤輸入的一行
                dos.writeUTF(line);//發給服務端
                System.out.println("client send msg : " + line);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    //監聽服務端回覆的消息
    public void listenServerReply(final DataInputStream dis){
        new Thread(){
            @Override
            public void run() {
                super.run();
                String line = null;
                try {
                    while((line = dis.readUTF()) != null){
                        System.out.println("client receive msg from server: " + line);
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }.start();
    }

}

先啓動服務端，再啓動客戶端，在客戶端的控制檯輸入消息並回車，就可以發送消息給客戶端了，客戶端收到消息後，馬上會回覆一個消息