【分析解答题】

综合应用题下面是一个Applet程序，其功能是捕捉用户所按下的键，并将捕捉到的键时间，传给程序，程序再将所按下的字符显示在Applet中。请改正程序中的错误(有下划线的语句)，使程序能输出正确的结果。注意：不改动程序的结构，不得增行或删行。程序运行结果如下：

import jav
A、awt.*;import jav
A、applet.*;/**/public class ex15_3 extends JApplet{ private String str1; private String str2; private String str3; public void init(){ str1 = "Character:"; str2 = "Number:"; str3 = "Key State:"; } public void paint(Graphics g){ g.drawString(str1, 20, 30); g.drawString(str2, 20, 50); g.drawString(str3, 20, 70); } public boolean keyUpEvent e, int n){str1 = "Character:" + String.valueOf(n);str2 = "Number:" + n;str3 = "Key State:Key Up";repaint();return true;} public boolean keyDownEvent e, int n){ str1 = "Character:" + String.valueOf(n); str2 = "Number:" + n;str3 = "Key State:KeyDown";repaint(); return true; }}ex15_3.html