java第一次上机实验--验证码

 1 package javashiyan;
 2 
 3 import java.awt.Color;
 4 import java.awt.event.ActionEvent;
 5 import java.awt.event.ActionListener;
 6 
 7 import javax.swing.*;
 8 
 9 public  class Yanzhen extends JFrame
10 {
11     //定义成员变量
12     private Mypanel mp;
13     private JButton b;
14     private JTextField txt;
15     private ActionListener listener;
16     
17     public Yanzhen()
18     {
19         Realize();
20     }
21     public void Realize()
22     {
23         JFrame f=new JFrame("验证码");
24         //实例化
25         b=new JButton();
26         b.addActionListener(listener);
27         ActionEvent e;
28         b.setIcon(new ImageIcon("D://button//刷新.jpg"));//载入图片
29         b.setLocation(200,100);//设置位置
30         b.setSize(32,32);//设置大小
31         b.setVisible(true);//设置显示
32         
33         txt=new JTextField();
34         txt.setSize(90,30);
35         txt.setLocation(10,100);
36         txt.setVisible(true);
37         
38         mp=new Mypanel();
39         mp.setSize(100,30);
40         mp.setLocation(100,100);
41         
42         JButton jb=new JButton();
43         
44         
45         f.add(mp);
46         f.add(b);
47         f.add(txt);
48         
49         f.setLayout(null);
50         f.setSize(400, 400);//设置界面大小
51         f.getContentPane().setBackground(Color.white);//设置界面的背景颜色
52         f.getContentPane().setVisible(true);
53         f.setVisible(true);
54     }
55 
56 
57 
58     public void actionPerformed(ActionEvent e) {
59         // TODO Auto-generated method stub
60         
61         
62     }
63 }

 1 package javashiyan;
 2 
 3 import java.awt.*;
 4 import java.util.*;
 5 
 6 public class Mypanel extends Panel {
 7     public void paint(Graphics g)
 8     {
 9         int height = 50;
10         int width = 90;
11         //验证码框背景颜色
12         g.setColor(Color.white);
13         //填充验证码背景
14         g.fillRect(0, 0, width, height);
15         g.setColor(Color.BLACK);
16         g.drawRect(0, 0, width-1, height-1);
17         Random r = new Random();
18         for(int i = 0;i<100;i++)
19         {
20             int x = r.nextInt(width)-1;
21             int y = r.nextInt(height)-1;
22             g.drawOval(x, y, 2, 2);//画干扰的圆点
23         }
24         for(int i=0;i<3;i++)
25         {
26             int x1=r.nextInt(width)-1;
27             int y1=r.nextInt(height)-1;
28             int x2=r.nextInt(width)-1;
29             int y2=r.nextInt(height)-1;
30             g.drawLine(x1, y1, x2, y2);//画干扰的线段
31         }
32         
33         g.setFont(new Font("黑体",Font.BOLD,20));//设置验证码字体以及大小
34         g.setColor(Color.BLUE);//设置验证码字体颜色
35         //生成随机验证码
36         char[] tmp = ("0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ").toCharArray();
37         StringBuilder sb = new StringBuilder();
38         for(int i = 0;i<4;i++)
39         {
40             int pos = r.nextInt(tmp.length);
41             char c = tmp[pos];
42             sb.append(c + " ");
43         }
44         g.drawString(sb.toString(), 10, 15);//写入验证码
45     }
46 }

 1 package javashiyan;
 2 
 3 
 4 
 5 import java.util.Random;
 6 
 7 public class main {
 8 
 9     public static void main(String[] args) 
10     {    
11             Yanzhen dang=new Yanzhen();
12     }
13 
14 }
15