UDP

UDP数据报通信

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.JScrollPane;import javax.swing.JTextArea;import javax.swing.JTextField;public class UDPChat 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;private byte inBuf[], outBuf[];public static final int BUFSIZE = 1024;public UDPChat() {mainJframe = new JFrame("聊天--UDP协议");con = mainJframe.getContentPane();showArea = new JTextArea();showArea.setEditable(false);showArea.setLineWrap(true);lbl1 = new JLabel("接收端口号:");lbl2 = new JLabel("发送端口号:");lbl3 = new JLabel("对方的地址:");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 UDPChat();}@Overridepublic void actionPerformed(ActionEvent e) {try {if (e.getSource() == startBtn) {inBuf = new byte[BUFSIZE];sendPort = Integer.parseInt(sendPortText.getText());sendIP = InetAddress.getByName(IPAddressText.getText());sendSocket = new DatagramSocket();receivePort = Integer.parseInt(receivePortText.getText());receivePack = new DatagramPacket(inBuf, BUFSIZE);receiveSocket = new DatagramSocket(receivePort);thread = new Thread(this);thread.setPriority(Thread.MIN_PRIORITY);thread.start();startBtn.setEnabled(false);sendBtn.setEnabled(true);msgText.setEditable(true);} else {outBuf = msgText.getText().getBytes();sendPack = new DatagramPacket(outBuf, outBuf.length, sendIP,sendPort);sendSocket.send(sendPack);showArea.append("我说:" + msgText.getText() + "\n");msgText.setText(null);}} catch (UnknownHostException e1) {showArea.append("无法连接到指定地址\n");} catch (SocketException e1) {showArea.append("无法打开指定端口\n");} catch (IOException e1) {showArea.append("发送数据失败\n");}}@Overridepublic void run() {String msgstr;while (true) {try {receiveSocket.receive(receivePack);msgstr = new String(receivePack.getData(), 0, receivePack.getLength());showArea.append("对方说:" + msgstr + "\n");} catch (IOException e1) {showArea.append("接受数据出错\n");}}}}

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