udpclientdemo.java

里面所含源码是本人平时做程序的一些实例

import java.net.*;
import java.io.*;

public class UDPClientDemo {
    private DatagramSocket s;
    private InetAddress hostAddress;
    private byte[] buf = new byte[1000];
    private DatagramPacket dp = new DatagramPacket(buf, buf.length);

    public UDPClientDemo() {
	try {
	    s = new DatagramSocket();
	    hostAddress = InetAddress.getByName("localhost");
	    System.out.println("Client start....");
	    while (true) {
		String strOutMess = "";
		BufferedReader stdin = new BufferedReader(
			new InputStreamReader(System.in));
		strOutMess = stdin.readLine();
		if (strOutMess.equals("bye"))
		    break;
		String strOut = "[Client say]:" + strOutMess;
		byte[] buf = strOut.getBytes();
		DatagramPacket out = new DatagramPacket(buf, buf.length,
			hostAddress, 4200);
		s.send(out);
		s.receive(dp);
		String strReceived = "(" + dp.getAddress() + ":" + dp.getPort()
			+ ")" + new String(dp.getData(), 0, dp.getLength());
		System.out.println(strReceived);
	    }
	} catch (UnknownHostException e) {
	    System.out.println("未找到服务器");
	    System.exit(1);
	} catch (SocketException se) {
	    System.out.println("打开套接字错误!");
	    se.printStackTrace();
	    System.exit(1);
	} catch (IOException ie) {
	    System.err.println("IO error!");
	}
    }

    /**
     * @param args
     */
    public static void main(String[] args) {
	// TODO Auto-generated method stub
	new UDPClientDemo();
    }

}