執行緒控制時間的隨筆（例項）

package kk;
import java.util.*;
import java.awt.EventQueue;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.Scanner;
import java.util.Timer;
import java.util.TimerTask;

import javax.swing.JOptionPane;




public class kk {
    float sum;
    String parten = "0.00";//為下一行程式碼初始化準備
    DecimalFormat decimal = new DecimalFormat(parten);//建立一個型別為DecimalFormat類的物件decimal
    String str;
    static Timer timer = null; 
    static SimpleDateFormat df=new SimpleDateFormat("mm:ss"); //控制時間的格式類   
    long starttime;
    long finishtime;
    long duration;
    long allduration;
    public kk()
    {
         timer = new Timer(); 
         finishtime=System.currentTimeMillis();
         starttime=finishtime;
         timer.schedule(new TimerTask() 
         {
             public void run() {    
                 finishtime=System.currentTimeMillis();
                 duration=finishtime-starttime;
                /* if(duration/1000==25&&summary<tishu)
                 {
                     JOptionPane.showMessageDialog(null, "答題時間已到。答題總題數為"+(dadui+dacuo)+",答對題數為"+dadui+",答錯題數為"+dacuo+",未答題題數為"+(tishu-dadui-dacuo)+",答題使用時間:"+(allduration+duration)/1000+"秒。");
                     frame.setVisible(false);
                     new 每天一練初級版題型選擇();
                 }
                 String str=df.format(new Date(duration)); 
                 T7.setText(str);*/
                 String str=df.format(new Date(duration)); 
                 System.out.print(str);
                 }  
             }, 1000, 1000);
    }
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    kk window = new kk();
                    Scanner qq=new Scanner(System.in);                 
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
}