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);
     }
 }