用java实现PC限时关机

转载：http://hi.baidu.com/triceratops/blog

import java.io.*;
import javax.swing.JOptionPane;

import java.util.Calendar;
import java.io.Serializable;

public class TimeController{
private Timer timer;
private File f = new File("timer");
public void execute(int hour) throws IOException,ClassNotFoundException,InterruptedException{
   FileInputStream fis;
   ObjectInputStream ois;
   while(true){
    try{
     fis = new FileInputStream(f);
     ois = new ObjectInputStream(fis);
     timer = (Timer)ois.readObject();
     ois.close();
    }
    catch(FileNotFoundException ioe){
     saveTimer(new Timer());
     continue;
    }
    if(timer.isTimeExhausted() && timer.isTodayOpened()){
     closePC();
     JOptionPane.showMessageDialog(null,"今日开机时间已经满"+hour+"小时！","警告！",0);
     break;
    }
    if(!timer.isTodayOpened()){
     timer.setTimeExhausted(false);
     timer.setDate();
    }
    timer.setStartTime();
    Thread.sleep(10*60*1000);
    timer.setCurrentTime();
    timer.addEclipsedSeconds();
    saveTimer(timer);
    if(timer.isShutdownTime(hour)){
     closePC();
     timer.reset();
     saveTimer(timer);
     JOptionPane.showMessageDialog(null,"请注意：10分钟后将自动关机！","警告！",0);
     break;
    }
   }
}

private void saveTimer(Timer timer) throws IOException{
   FileOutputStream fos = new FileOutputStream(f);
   ObjectOutputStream oos = new ObjectOutputStream(fos);
   oos.writeObject(timer);
   oos.close();
}

private void closePC() {
   new Thread(new Runnable(){
    public void run() {
     try{
      if(timer.getEclipsedSeconds() != 0)
       Thread.sleep(10*60*1000);
      Runtime.getRuntime().exec("shutdown -s");
     }
     catch(Exception e){
      e.printStackTrace();
     }
    }
   }).start();
}

public static void main(String[] args) throws Exception{
   int hour = 3;
   if(args.length != 0)
    hour = Integer.parseInt(args[0]);
   new TimeController().execute(hour);
}
}

=============================================

public class Timer implements Serializable{
transient private long startTime;
transient private long currentTime;
private long eclipsedSeconds;
private boolean timeExhausted;
private int date;

public Timer(){
   setStartTime();
   setCurrentTime();
   setDate();
}

public void setStartTime(){
   startTime = Calendar.getInstance().get(Calendar.HOUR_OF_DAY)*60*60+
     Calendar.getInstance().get(Calendar.MINUTE)*60+
     Calendar.getInstance().get(Calendar.SECOND);
}

public long getStartTime(){
   return startTime;
}

public void setCurrentTime(){
   currentTime = Calendar.getInstance().get(Calendar.HOUR_OF_DAY)*60*60+
       Calendar.getInstance().get(Calendar.MINUTE)*60+
       Calendar.getInstance().get(Calendar.SECOND);
}

public long getCurrentTime(){
   return currentTime; 
}

public void addEclipsedSeconds(){
   eclipsedSeconds += currentTime - startTime;
}

public long getEclipsedSeconds(){
   return eclipsedSeconds;
}

public void setDate(){
   date = Calendar.getInstance().get(Calendar.DATE);
}

public int getDate(){
   return date;
}

public void setTimeExhausted(boolean timeExhausted){
   this.timeExhausted = timeExhausted;
}

public boolean isTimeExhausted(){
   return timeExhausted;
}

public boolean isTodayOpened(){
   return date == Calendar.getInstance().get(Calendar.DATE);
}

public boolean isShutdownTime(int hour){
   if(eclipsedSeconds>=hour*60*60)
    return true;
   return false;
}

public void reset(){
   eclipsedSeconds = 0;
   setTimeExhausted(true);
}

public String toString(){
   String eclipsedTime = "今日累计使用了：";
   long temp = getEclipsedSeconds();
   eclipsedTime += temp/(60*60) + "小时";
   temp = temp%(60*60);
   eclipsedTime += temp/60 + "分";
   temp = temp%60;
   eclipsedTime += temp + "秒";
   return eclipsedTime;
}
}