liaotian.rar_UDP_使用UDP套接字编程_在局域网中进行点对点聊天的程序_聊天 点对点

import java.io.*; import java.net.*; import java.awt.event.*; import java.awt.*; import javax.swing.*; public class liaotian implements Runnable,ActionListener{ JTextArea showArea; JLabel lbl1,lbl2,lbl3; JTextField msgText,sendPortText,receivePortText,IPAddressText; JFrame mainJframe; JButton sendBtn,startBtn; JScrollPane JSPane; JPanel pane1,pane2; Container con; Thread thread=null; DatagramPacket sendPack,receivePack; DatagramSocket sendSocket,receiveSocket; private InetAddress sendIP; private int sendPort,receivePort; //存储发送端口和接收端口 private byte inBuf[], outBuf[]; public static final int BUFSIZE=1024; public liaotian() { mainJframe=new JFrame("liaotian"); con=mainJframe.getContentPane(); showArea=new JTextArea(); showArea.setEditable(false); showArea.setLineWrap(true); lbl1=new JLabel("我的端口号:"); lbl2=new JLabel("对方端口号:"); lbl3=new JLabel("对方的IP地址:"); sendPortText=new JTextField(); sendPortText.setColumns(5); receivePortText=new JTextField(); receivePortText.setColumns(5); IPAddressText=new JTextField(); IPAddressText.setColumns(8); startBtn=new JButton("开始"); startBtn.addActionListener(this); pane1=new JPanel(); pane1.setLayout(new FlowLayout()); pane1.add(lbl1); pane1.add(receivePortText); pane1.add(lbl2); pane1.add(sendPortText); pane1.add(lbl3); pane1.add(IPAddressText); pane1.add(startBtn); JSPane=new JScrollPane(showArea); msgText=new JTextField(); msgText.setColumns(40); msgText.setEditable(false); msgText.addActionListener(this); sendBtn=new JButton("发送"); sendBtn.setEnabled(false); sendBtn.addActionListener(this); pane2=new JPanel(); pane2.setLayout(new FlowLayout()); pane2.add(msgText); pane2.add(sendBtn); con.add(pane1,BorderLayout.NORTH); con.add(JSPane,BorderLayout.CENTER); con.add(pane2,BorderLayout.SOUTH); mainJframe.setSize(600,400); mainJframe.setVisible(true); mainJframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); } public static void main(String[] args) { new liaotian(); } public void actionPerformed(ActionEvent e) { try{ if(e.getSource()==startBtn){ //按下了开始按钮 inBuf=new byte[BUFSIZE]; sendPort=Integer.parseInt(sendPortText.getText()); sendIP=InetAddress.getByName(IPAddressText.getText()); sendSocket=new DatagramSocket(); receivePort=Integer.parseInt(receivePortText.getText()); //创建接收数据包 receivePack=new DatagramPacket(inBuf,BUFSIZE); //指定接收数据的端口 receiveSocket=new DatagramSocket(receivePort); //创建线程准备接收对方的消息 thread=new Thread(this); thread.setPriority(Thread.MIN_PRIORITY); thread.start(); startBtn.setEnabled(false); sendBtn.setEnabled(true); msgText.setEditable(true); }else{ //按下了发送按钮或回车键 outBuf=msgText.getText().getBytes(); //组装要发送的数据包 sendPack=new DatagramPacket(outBuf,outBuf.length,sendIP, sendPort); //发送数据 sendSocket.send(sendPack); showArea.append("我："+msgText.getText()+"\n"); msgText.setText(null); } }catch(UnknownHostException el){ showArea.append("无法连接到指定地址\n"); }catch(SocketException el){ showArea.append("无法打开指定端口\n"); }catch(IOException el){ showArea.append("发送数据失败\n"); } } //在线程中接收数据 public void run() { String msgstr; while (true){ try{ //注意这个try的位置 receiveSocket.receive(receivePack); msgstr=new String(receivePack.getData(),0,receivePack. getLength()); showArea.append(sendPort+"："+msgstr+"\n"); }catch(IOException el){ showArea.append("接收数据出错\n"); } } } }