import java. awt. *;import java applet. public class mark extends Applet int i; Point Marks; public void inito Marks =new Point 20; i=20;3 boolean mouseDown(Event evt, int x, int y) i Marks i++l=new Point(x, y); repaint: public void paint( graphics g) int k: for(k=0;k≤i;k++){ g fillOval(Marks kX, Marks[k y, 10, 109 . 3.2鼠标产生的事件 boolean mouseDown(Event evt, int x, int y) { Marks[i++]=new Point(x,y); repaint(); } public void paint(Graphics g) { int k; for (k=0;k<i;k++){ g.fillOval(Marks[k].x,Marks[k].y,10,10); } import java.awt.*;import java.applet.*; public class mark extends Applet { int i; Point Marks[]; public void init() {Marks[] =new Point[20]; i=20;}