下面是一个Applet程序，程序的功能是用鼠标画图。本题是通过单击鼠标后画出一个Java字。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，不得增行或减行。源程序文件代码清单如下；import java.awt.*;import java.awt.event.*;import java.applet.*;/*＜applet code=SimpleHitMouse.java width=800 height=400＞＜/applet＞*/public class SimpleHitMouse implements Applet{private java.util.Vector points=new java.util.Vector();public void init(){addMouseListener(new MouseAdapter(){public void mousePressed(MouseEvent e){points.add(new Point(e.getX(),e.getY())paint();}}public void update(Graphics g)repaint(g);}public void paint(Graphics g){for(int i=0;i＜points.size();i++){Point dot=(Point)points.elementAt(i);g.drawString("x",dot.x,dot.y);}}public static void main(String args[ ]){Frame. fram=new Frame("CelayTree");SimpleHitMouse dot=new SimpleHitMouse();dot.init ();dot.start ();fram.add ( "Center", dot );fram.setSize( 400,300 );fram.addWindowListener( new WindowAdapter(){public void windowClosing( WindowEvent e ){System.exit(0);}});fram.show ();}}ex12_3.html:＜html＞＜head＞＜title＞A Simple Program＜/title＞＜/head＞＜body＞＜applet code=" SimpleHitMouse.class" width=800 height=400＞＜/applet＞＜/body＞＜/html＞
下面是一个Applet程序，程序的功能是用鼠标画图。本题是通过单击鼠标后画出一个Java字。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，不得增行或减行。
源程序文件代码清单如下；
import java.awt.*;
import java.awt.event.*;
import java.applet.*;
/*
＜applet code=SimpleHitMouse.java width=800 height=400＞
＜/applet＞
*/
public class SimpleHitMouse implements Applet
{
private java.util.Vector points=new java.util.Vector();
public void init()
{
addMouseListener(new MouseAdapter()
{
public void mousePressed(MouseEvent e)
{
points.add(new Point(e.getX(),e.getY())
paint();
}
}
public void update(Graphics g)
repaint(g);
}
public void paint(Graphics g)
{
for(int i=0;i＜points.size();i++)
{
Point dot=(Point)points.elementAt(i);
g.drawString("x",dot.x,dot.y);
}
}
public static void main(String args[ ])
{
Frame. fram=new Frame("CelayTree");
SimpleHitMouse dot=new SimpleHitMouse();
dot.init ();
dot.start ();
fram.add ( "Center", dot );
fram.setSize( 400,300 );
fram.addWindowListener( new WindowAdapter(){
public void windowClosing( WindowEvent e )
{
System.exit(0);
}
});
fram.show ();
}
}
ex12_3.html:
＜html＞
＜head＞
＜title＞A Simple Program＜/title＞
＜/head＞
＜body＞
＜applet code=" SimpleHitMouse.class" width=800 height=400＞
＜/applet＞
＜/body＞
＜/html＞