timeserver.java

Java实例入门

package udptimeserver;
import java.net.*;
import java.util.*;
import java.io.*;
import java.text.*;
import javax.swing.text.*;
/**
 * Title:        时钟服务程序
 * Description:  这是一个使用用户数据报协议（UDP）实现的简单时钟服务器
 * Copyright:    Copyright (c) 2001
 * Company:
 * @author
 * @version 1.0
 */

public class timeServer extends Thread {
  private  int ServerPort=13;
  private DatagramSocket serverSocket=null;
  private boolean running=true;
  private JTextComponent outText=null;
  public timeServer(JTextComponent outComponent) {
      try{
           outText=outComponent;
           serverSocket=new DatagramSocket(ServerPort);
      }catch(Exception e){
      }
  }
  public timeServer(int newPort,JTextComponent outComponent) {
      try{
           outText=outComponent;
           ServerPort=newPort;
           serverSocket=new DatagramSocket(newPort);
      }catch(Exception e){
      }
  }
  public void setOutText(JTextComponent newComponent){
      outText=newComponent;
  }
  public void run(){
     outText.setText(outText.getText()+"时钟服务启动，端口为"+ServerPort+"\n");
     while(running){
        try{
            byte[]  buffer=new byte[1];
             DatagramPacket dataPacket=new DatagramPacket(buffer,buffer.length );
             serverSocket.receive(dataPacket);
             InetAddress clientAddress=dataPacket.getAddress();
            int clientPort=dataPacket.getPort() ;
             buffer=getTime();
             String strTime=new String(buffer);
             outText.setText(outText.getText()+strTime+" 向"+clientAddress.toString()
                             +":"+clientPort+"发送数据报\n");
             dataPacket=new DatagramPacket(buffer,buffer.length,clientAddress,clientPort );
             serverSocket.send(dataPacket);
        }catch(IOException e){
        }
    }
    serverSocket.close();
    outText.setText(outText.getText()+"服务停止\n");
 }
  private byte[] getTime(){
     Date currentTime=new Date();
     SimpleDateFormat dateFormat=new SimpleDateFormat("yyyy MMMM dd,EEEE, HH:mm:ss");
     String timeString=dateFormat.format(currentTime);
     return timeString.getBytes() ;
  }
  public void finalize(){
     if(serverSocket!=null)
         serverSocket.close();
  }
  public void stopServer(){
     running=false;
  }
}