Java实现的计时器【秒表】功能示例

import javax.swing.*;

import java.awt.headlessexception;

import java.awt.borderlayout;

import java.awt.flowlayout;

import java.awt.font;

import java.awt.event.actionlistener;

import java.awt.event.actionevent;

/**

  * 计时器

  */

public class timer extends jframe {

   /**

  *

  */

  private static final long serialversionuid = 1l;

  private static final string initial_label_text = "0 000" ;

   // 计数线程

   private countingthread thread = new countingthread();

   // 记录程序开始时间

   private long programstart = system.currenttimemillis();

   // 程序一开始就是暂停的

   private long pausestart = programstart;

   // 程序暂停的总时间

   private long pausecount = 0 ;

   private jlabel label = new jlabel(initial_label_text);

   private jbutton startpausebutton = new jbutton( "开始" );

   private jbutton resetbutton = new jbutton( "清零" );

   private actionlistener startpausebuttonlistener = new actionlistener() {

     public void actionperformed(actionevent e) {

       if (thread.stopped) {

         pausecount += (system.currenttimemillis() - pausestart);

         thread.stopped = false ;

         startpausebutton.settext( "暂停" );

       } else {

         pausestart = system.currenttimemillis();

         thread.stopped = true ;

         startpausebutton.settext( "继续" );

       }

     }

   };

   private actionlistener resetbuttonlistener = new actionlistener() {

     public void actionperformed(actionevent e) {

       pausestart = programstart;

       pausecount = 0 ;

       thread.stopped = true ;

       label.settext(initial_label_text);

       startpausebutton.settext( "开始" );

     }

   };

   public timer(string title) throws headlessexception {

     super (title);

     setdefaultcloseoperation(exit_on_close);

     setlocation( 300 , 300 );

     setresizable( false );

     setupborder();

     setuplabel();

     setupbuttonspanel();

     startpausebutton.addactionlistener(startpausebuttonlistener);

     resetbutton.addactionlistener(resetbuttonlistener);

     thread.start(); // 计数线程一直就运行着

   }

   // 为窗体面板添加边框

   private void setupborder() {

     jpanel contentpane = new jpanel( new borderlayout());

     contentpane.setborder(borderfactory.createemptyborder( 5 , 5 , 5 , 5 ));

     this .setcontentpane(contentpane);

   }

   // 配置按钮

   private void setupbuttonspanel() {

     jpanel panel = new jpanel( new flowlayout());

     panel.add(startpausebutton);

     panel.add(resetbutton);

     add(panel, borderlayout.south);

   }

   // 配置标签

   private void setuplabel() {

     label.sethorizontalalignment(swingconstants.center);

     label.setfont( new font(label.getfont().getname(), label.getfont().getstyle(), 40 ));

     this .add(label, borderlayout.center);

   }

   // 程序入口

   public static void main(string[] args) {

     try {

       uimanager.setlookandfeel(uimanager.getsystemlookandfeelclassname());

     } catch (exception e) {

       e.printstacktrace();

     }

     timer frame = new timer( "HdhCmsTesttuohang.net 计时器" );

     frame.pack();

     frame.setvisible( true );

   }

   private class countingthread extends thread {

     public boolean stopped = true ;

     private countingthread() {

       setdaemon( true );

     }

     @override

     public void run() {

       while ( true ) {

         if (!stopped) {

           long elapsed = system.currenttimemillis() - programstart - pausecount;

           label.settext(format(elapsed));

         }

         try {

           sleep( 1 ); // 1毫秒更新一次显示

         } catch (interruptedexception e) {

           e.printstacktrace();

           system.exit( 1 );

         }

       }

     }

     // 将毫秒数格式化

     private string format( long elapsed) {

       int hour, minute, second, milli;

       milli = ( int ) (elapsed % 1000 );

       elapsed = elapsed / 1000 ;

       second = ( int ) (elapsed % 60 );

       elapsed = elapsed / 60 ;

       minute = ( int ) (elapsed % 60 );

       elapsed = elapsed / 60 ;

       hour = ( int ) (elapsed % 60 );

       return string.format( "%02d:%02d:%02d %03d" , hour, minute, second, milli);

     }

   }

}