Java使用TCP聊天程序

前面使用了UDP进行通信的聊天程序

现在做一个用TCP进行通信的聊天程序

原理：

ServerSocket Socket

1.开一个线程监听端口，准备接收消息

2.不断接受消息发送到目的端口

P.S.因为TCP是面向连接的所以中间要注意先后顺序，代码写得有点乱

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

/**
 * 聊天程序
 * TCP实现
 * 开一个线程监听一个端口，接收消息
 * @author GXF
 *
 */
public class TcpChatWindow {
    private int destPort;                        //目的端口
    private int listenPort;                        //监听端口
    private Socket socketToSendMessage;            //发送消息的socket
    
    public TcpChatWindow(int destPort, int listenPort){
        this.destPort = destPort;
        this.listenPort = listenPort;
        
        //init
        init();
    }
    
    /**
     * 接收消息线程
     * @author GXF
     *
     */
    class ReceiveMessageThread implements Runnable{
        //接收消息socket
        private ServerSocket receiveMessageSocket;
        
        @Override
        public void run() {
            //init
            init();
            while(true){
                try {
                    Socket clientSocket = receiveMessageSocket.accept();
                    InputStream inputStreamOfClientSocket = clientSocket.getInputStream();
                    byte buff[] = new byte[1024];
                    int lengthOfMessage = -1;
                    StringBuilder sb = new StringBuilder();
                    //read message
                    while((lengthOfMessage = inputStreamOfClientSocket.read(buff)) > 0){
                        sb.append(new String(buff, 0, lengthOfMessage));
                    }//while
                    //输出消息到控制台
                    System.out.println(sb.toString());
                    //关闭socket
                    clientSocket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        
        /**
         * 对线程进行初始化
         */
        public void init(){
            try {
                receiveMessageSocket = new ServerSocket(listenPort);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        
    }
    
    //初始化操作
    private void init(){
            
        //start ReceiveMessageThread
        Thread receiveMessageThread = new Thread(new ReceiveMessageThread());
        receiveMessageThread.start();
        //input message and send message
        while(true){
            Scanner scanner = new Scanner(System.in);
            String messageToSend = scanner.nextLine();
//            getSocketToSendMessage();
            sendMessage(messageToSend);
            scanner.close();
        }
            
        
    }
    
    /**
     * 向对方发送消息
     * @param message
     */
    public void sendMessage(String message){
        try {
            Socket socketToSendMessage = new Socket(InetAddress.getByName("127.0.0.1"), destPort);
            OutputStream outputStreamOfClientSocket = socketToSendMessage.getOutputStream();
            byte bytesOfMessage[] = message.getBytes();
            outputStreamOfClientSocket.write(bytesOfMessage);
            socketToSendMessage.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    //获取发送消息的socket
    public Socket getSocketToSendMessage(){
        if(socketToSendMessage == null){
            try {
                socketToSendMessage = new Socket(InetAddress.getByName("127.0.0.1"), destPort);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        return socketToSendMessage;
    }
    
    public static void main(String args[]){
        if(args.length != 2){
            System.out.println("usage: java TcpChatWindow destport listenport");
            return;
        }
        int destPort = Integer.valueOf(args[0]);
        int listenPort = Integer.valueOf(args[1]);
        
        TcpChatWindow chatWindow = new TcpChatWindow(destPort, listenPort);
    }
}