Socket

1.

ServerSocket ss = new ServerSocket(port); 
  while(true){ //如果有客户端的连接请求，将执行下面的操作 
  Socket client = ss.accept(); //新建客户端对象 
  Handle handle = new Handle(client);//启动个客户端线程,并且一直监听，直到退出，若有多个客户端请求,则会新建多个客户端线程，由此实现多线程 
  } 


public class Handle implements Runnable{ 
Socket socket; 
public Handle(Socket socket){ 
this.socket = socket; 
new Thread(this).start();   
} 
public void run(){ 
try{ 
  BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream())); 
            writer.write("返回服务器处理的消息给客户端"); 
            writer.flush(); 
            writer.close();//关闭这个socket 

         } catch (Exception e){ 
} 
}

2

为了方便用户使用Socket进行通信，Java把Socket封装成了类。如果查看Socket类的源码，代码是比较长的。我们这里创建了一个Socket_来表示下它。

public class Socket_ {

    public Socket_() {
    }

    public Socket_(Proxy proxy) {
    }

    public Socket_(SocketImpl impl) {
    }

    public Socket_(String host, int port) {
    }

    public Socket_(InetAddress addr, int port) {
    }

    public Socket_(String host, int port, InetAddress localAddr, int localPort) {
    }

    public Socket_(InetAddress addr, int port, InetAddress localAddr,
            int localPort) {
    }

    public InputStream getInputStream() {
        return null;
    }

    public OutputStream getOutputStream() {
        return null;
    }

}

 这样我们可以对Socket类有了大致的了解，对于一般用户只要知道这个套接字能够连接到另一台计算机，并能够获取数据输入输出流着就足够了。

import java.io.IOException;
import java.io.InputStream;
import java.net.Socket;
import java.net.UnknownHostException;

public class TestSocket {

    public static final int BUF_SIZE = 1024;

    public static void main(String[] args) {
        try {
            Socket socket = new Socket("localhost", 5000);
            InputStream input = socket.getInputStream();

            // 好了，接下来就是InputStream对象的事了
            // 就像以前介绍的那样，我们将获得大量的数据流
            // 哈哈，准备接收数据吧
            // 这次我们考虑InputStream流的read(byte[] b)方法

            byte[] buf = new byte[BUF_SIZE];
            int readCount = 0;
            while ((readCount = input.read(buf)) != 0) {
                //处理数据buf
            }

        } catch (UnknownHostException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}