Java课程设计局域网络广播系统源代码

import java.io.*; import java.net.*; import java.awt.*; import java.awt.event.*; import javax.swing.Timer; public class BroadCastWord extends Frame implements ActionListener { int port; InetAddress group=null; MulticastSocket socket=null; Timer time=null; FileDialog open=null; Button select,开始广播,停止广播; File file=null; String FileDir=null,fileName=null; FileReader in=null; BufferedReader bufferIn=null; int token=0; TextArea 显示正在播放内容,显示已播放的内容; public BroadCastWord() { super("单词广播系统"); select=new Button("选择要广播的文件"); 开始广播=new Button("开始广播"); 开始广播.setEnabled(false); 停止广播=new Button("停止广播"); select.addActionListener(this); 开始广播.addActionListener(this); 停止广播.addActionListener(this); time=new Timer(2000,this); open=new FileDialog(this,"选择要广播的文件",FileDialog.LOAD); 显示正在播放内容=new TextArea(10,10); 显示正在播放内容.setForeground(Color.blue); 显示已播放的内容=new TextArea(10,10); Panel north=new Panel(); north.add(select); north.add(开始广播); north.add(停止广播); add(north,BorderLayout.NORTH); Panel center=new Panel(); center.setLayout(new GridLayout(1,2)); center.add(显示正在播放内容); center.add(显示已播放的内容); add(center,BorderLayout.CENTER); validate(); try { port=5000; group=InetAddress.getByName("239.255.0.0"); socket=new MulticastSocket(port); socket.setTimeToLive(1); socket.joinGroup(group); } catch(Exception e) { System.out.println("Error: "+ e); } setBounds(100,50,360,380); setVisible(true); addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); } public void actionPerformed(ActionEvent e) { if(e.getSource()==select) { 显示已播放的内容.setText(null); open.setVisible(true); fileName=open.getFile(); FileDir=open.getDirectory(); if(fileName!=null) { time.stop(); file=new File(FileDir,fileName); try { file=new File(FileDir,fileName); in=new FileReader(file); bufferIn=new BufferedReader(in); 开始广播.setEnabled(true); } catch(IOException ee) { } } } else if(e.getSource()==开始广播) { time.start(); } else if(e.getSource()==time) { String s=null; try { if(token==-1) { file=new File(FileDir,fileName); in=new FileReader(file); bufferIn=new BufferedReader(in); } s=bufferIn.readLine(); if(s!=null) { token=0; 显示正在播放内容.setText("正在广播的内容:\n"+s); 显示已播放的内容.append(s+"\n"); DatagramPacket packet=null; byte data[]=s.getBytes(); packet=new DatagramPacket(data,data.length,group,port); socket.send(packet); } else { token=-1; } } catch(IOException ee) { } } else if(e.getSource()==停止广播) { time.stop(); } } public static void main(String[] args) { BroadCastWord broad=new BroadCastWord(); } }