使用AWT组件实现验证码功能 
 1 import java.awt.Color;
 2 import java.awt.Font;
 3 import java.awt.FontMetrics;
 4 import java.awt.Graphics2D;
 5 import java.awt.image.BufferedImage;
 6 import java.io.File;
 7 import java.io.IOException;
 8 import java.util.Random;
 9 
10 import javax.imageio.ImageIO;
11 
12 public class Test {
13 
14     /**
15      * @param args
16      * @throws IOException 
17      */
18     public static void main(String[] args) throws IOException {
19         //用于随机生成验证码的字符串集
20         String[] strs = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R"
21                         ,"S","T","U","V","W","X","Y","Z","a","b","c","d","e","f","g","h","i","j"
22                         ,"k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","0","1"
23                         ,"2","3","4","5","6","7","8","9"};
24         //随机生成干扰线的纵坐标y1和y2
25         Random y1Random = new Random();
26         Random y2Random = new Random();
27         int y1 = y1Random.nextInt(31);
28         int y2 = y2Random.nextInt(31);
29         
30         //随机生成用于组成验证码的字符串所在集的下标值
31         Random code1Random = new Random();
32         Random code2Random = new Random();
33         Random code3Random = new Random();
34         Random code4Random = new Random();
35         int code1Index = code1Random.nextInt(62);
36         int code2Index = code2Random.nextInt(62);
37         int code3Index = code3Random.nextInt(62);
38         int code4Index = code4Random.nextInt(62);
39         
40         //随机生成rgb颜色
41         Random rRandom = new Random();
42         Random gRandom = new Random();
43         Random bRandom = new Random();
44         int r = rRandom.nextInt(256);
45         int g = gRandom.nextInt(256);
46         int b = bRandom.nextInt(256);
47         Color color = new Color(r, g, b);
48         
49         //拼接成完整字符串
50         String codeString = strs[code1Index] + strs[code2Index] + strs[code3Index] + strs[code4Index];
51         
52         //定义一个宽70像素,高30像素的jpg图片
53         BufferedImage bi = new BufferedImage(70, 30, BufferedImage.TYPE_INT_RGB);
54         //定义graphis绘画对象
55         Graphics2D graphics2d = bi.createGraphics();        
56         graphics2d.setBackground(Color.WHITE);
57         graphics2d.setColor(color);
58         graphics2d.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 20));
59         graphics2d.clearRect(0, 0, 70, 30);
　　　　　　 //绘制干扰线
60         graphics2d.drawLine(0, y1, 70, y2);
61         
62         //居中绘制字符串
63         FontMetrics fontMetrics = graphics2d.getFontMetrics();
64         int stringWidth = fontMetrics.stringWidth(codeString);
65         int stringAscent = fontMetrics.getAscent();
66         int xCode = 70 / 2 - stringWidth / 2;
67         int yCode = 30 / 2 + stringAscent / 2;
68         graphics2d.drawString(codeString, xCode, yCode);
69         
70         //输出图片
71         File file = new File("C:\\Users\\zhengbing\\Desktop\\image.jpg");
72         ImageIO.write(bi, "jpeg", file);
73     }
74 
75 }

最后可以返回校验字符串codeString,来达到验证的功能

 posted on 2013-09-10 12:08  小网民  阅读(431)  评论(0)  编辑  收藏  举报