java怎么在swing文本框中实现一个时间倒计时的界面？项目需要，谢谢

通常可以设置某个固定的切换时间，之后显示固定的或者是随机的显示某张图片，举例：importjava.awt.*;importjava.awt.event.*;importjavax.swing.*;publicclassMousDemoextendsJFrame{MyJPanelmp;intindex;ImageIcon[]imgs={newImageIcon("C:\\Users\\lenovo\\Desktop\\a.png"),newImageIcon("C:\\Users\\lenovo\\Desktop\\b.png")};publicMousDemo(){mp=newMyJPanel(false);this.add(mp);this.setSize(300,200);this.setDefaultCloseOperation(EXIT_ON_CLOSE);this.setTitle("鼠标窗口");this.setVisible(true);/***方式一，使用TImer来切换图片*Swing下的Timer组件，个人觉得非常适合*Timer(200,newActionListener());意思就是每200毫秒执行一次ActionListener里面的方法**/Timertimer=newTimer(200,newActionListener(){@OverridepublicvoidactionPerformed(ActionEvente){mp.flag=!mp.flag;mp.repaint();}});timer.start();}publicstaticvoidmain(String[]args){newMousDemo();}classMyJPanelextendsJPanel{booleanflag;publicMyJPanel(booleanflag){this.flag=flag;}@Overridepublicvoidpaint(Graphicsg){super.paint(g);if(flag==false){g.drawImage(imgs[0].getImage(),0,0,this);}else{g.drawImage(imgs[1].getImage(),0,0,this);}}}}