DatagramSocket编程

大家好，又见面了，我是你们的朋友全栈君。

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JTextField;

public class Talk extends JFrame{
	JLabel la=new JLabel("请输入");
	JTextField tfd=new JTextField(20);
	JButton but=new JButton("发送");
	JPanel p=new JPanel();
	JTextArea jta=new JTextArea(10,20);
	Container c;
	DatagramSocket ds;
	DatagramReceive dc;
	int localPost=3000;
	int remotePost=5000;
	boolean flag=true;
	public void init(){
		c=this.getContentPane();
		c.setLayout(new BorderLayout());
		p.setLayout(new FlowLayout());
		p.add(la);p.add(tfd);p.add(but);
		c.add(p,BorderLayout.NORTH);
		c.add(jta,BorderLayout.CENTER);
		but.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				String temp=tfd.getText();
				jta.append("\n我说："+temp);
				byte[] buf=temp.getBytes();
				try {
					DatagramPacket dp=new DatagramPacket(buf,buf.length,InetAddress.getByName("localhost"),remotePost);
					try {
						ds.send(dp);
					} catch (IOException e1) {
						// TODO Auto-generated catch block
						e1.printStackTrace();
					}
					if(temp.trim().equals("bye")){
						flag=false;
						//dc.close();
					}
				} catch (UnknownHostException e1) {
					// TODO Auto-generated catch block
					e1.printStackTrace();
				}
				
			}
		});
	this.setSize(500,500);
	this.setVisible(true);
	}
	public Talk(String name,int localPost,int remotePost){
		super(name);
		this.localPost=localPost;
		this.remotePost=remotePost;
		init();
		try {
			ds=new DatagramSocket(localPost);
			dc=new DatagramReceive(name,ds,jta);
			dc.start();
		} catch (SocketException e) {
			// TODO Auto-generated catch block
			System.out.println("DatagramSocket创建失败");
		}
		
	}
	public static void main(String[] args) {
		Talk t1=new Talk("A",3000,5000);
		Talk t2=new Talk("B",5000,3000);
	}

}

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

import javax.swing.JTextArea;

public class DatagramReceive extends Thread{
	String name;
	DatagramSocket ds;
	JTextArea jta;
	boolean flag=true;
	public DatagramReceive(String name,DatagramSocket ds,JTextArea jta){
		this.name=name;
		this.ds=ds;
		this.jta=jta;
	}
		public void run(){
			while(flag){
				byte[] buf=new byte[1024];
				DatagramPacket dp=new DatagramPacket(buf,buf.length);
				try {
					ds.receive(dp);
					String temp=new String(buf,0,dp.getLength());
					jta.append("\n对方说："+temp);
					if(temp.trim().equals("bye")){
						flag=false;
						ds.close();
					}
				} catch (IOException e) {
					// TODO Auto-generated catch block
					System.out.println(name+"接受失败");
				}
				
			}
		}

}