网络编程（二） 多线程

入口：
package chat;

import java.net.DatagramSocket;
import java.net.SocketException;

public class chat {

	/**
	 * @param args
	 * @throws SocketException 
	 */
	public static void main(String[] args) throws SocketException {
		// TODO Auto-generated method stub
		DatagramSocket sd = new DatagramSocket();
		DatagramSocket re = new DatagramSocket(9000);
		
		send s = new send(sd);
		receive r = new receive(re);
		
		new Thread(s).start();
		new Thread(r).start();
	}

}





发送端：
package chat;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;

public class send implements Runnable {
	public DatagramSocket ds;
	
	public send(DatagramSocket ds) throws SocketException
	{
		this.ds = ds;
	}
	
	@Override
	public void run() {
		// TODO Auto-generated method stub
		try {
			InetAddress ip = InetAddress.getByName("192.168.1.255");
			
			String line = null;
			
			//第三步：创建UDP数据包
			System.out.println("开始聊天了：");
			BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
			while((line=in.readLine())!=null)
			{			
				byte[] buf = line.getBytes();	
				DatagramPacket dp = new DatagramPacket(buf, buf.length, ip, 9000);
				ds.send(dp);
				if("over".equals(line)) break;
			}
			ds.close();
		} catch (UnknownHostException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}		
	}

}




接收端：

package chat;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;

public class receive implements Runnable {
	public DatagramSocket ds;
	
	public receive(DatagramSocket ds)
	{
		this.ds = ds;
	}

	@Override
	public void run() {
		// TODO Auto-generated method stub
		try {
			byte[] buf = new byte[1024];
			
			while(true)
			{
				DatagramPacket dp = new DatagramPacket(buf,buf.length);
				ds.receive(dp);  //阻塞式
				
				//第三步：解析接收到的udp包
				String host = dp.getAddress().getHostName();
				int port = dp.getPort();
				String data = new String(dp.getData(),0,dp.getLength());
				System.out.println("聊天内容是：");
				System.out.println(host+"："+data);
				System.out.println(" ");
			}
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}		
	}

}