Java网络编程技术-03.ppt

Java程序设计 第3章 UDP协议网络编程 3.5 UDP网络编程案例 1）网络编程UDP协议的“Hello，world”程序 import java.net.*; import java.io.*; public class UDPClient { public static void main(String[] args)throws SocketException,IOException { String h=hello,world; byte[] b=h.getBytes(); InetAddress iip=InetAddress.getByName(localhost); DatagramSocket ds=new DatagramSocket(); DatagramPacket dp=new DatagramPacket(b,b.length,iip,3334); ds.send(dp); } } 2）UDP协议聊天程序 import java.awt.*; import java.awt.event.*; import java.io.*; import java.net.*; class myClient extends Frame { DatagramSocket ds1; DatagramPacket dp1=null; DatagramSocket ds2; DatagramPacket dp2=null; InetAddress iip; byte[] b; Panel p1,p2; Button bs; TextArea t1; TextField t2,t3; Label l1,l2; ttc t; myClient(String ss) throws SocketException ,IOException { super(ss); p1=new Panel(); p2=new Panel(); t1=new TextArea(); t2=new TextField(那你就去吧,别让妖精迷住! ,34); l1=new Label(昵称); l2=new Label(消息); t3=new TextField(悟空); bs=new Button( 发送 ); bs.addActionListener(new bss()); addWindowListener(new ww()); setLayout(new FlowLayout()); p1.setLayout(new BorderLayout()); p1.add(t1); add(p1); p2.setLayout(new FlowLayout()); p2.add(l1); p2.add(t3); p2.add(l2); p2.add(t2); p2.add(bs); add(p2); setBounds(100,100,460,260); setVisible(true); ds1=new DatagramSocket(); ds2=new DatagramSocket(3335); iip=InetAddress.getByName(localhost); t=new ttc(this); t.start(); } class bss implements ActionListener { public void actionPerformed(ActionEvent e) { try { dp1=new DatagramPacket((t3.getText().trim()+:+t2.getText().trim()).getBytes(),((t3.getText()+t2.getText().trim()).getBytes()).length,iip,3334); ds1.send(dp1); t1.append(t3.getText().trim()+:+t2.getText()+\n); } catch(IOException e1) {} } } class ww extends WindowAdapter { public void windowClosing(WindowEvent ee) { System.exit(0); } } public static void main(String[] args) throws IOException,SocketException { new myClient(Client); } } class ttc extends Thread { myClient mc=null; ttc(myClient mc) { this