彩色验证码实现
public class VerifyCode {
2 static Random r = new Random();
3 static String ssource = " ABCDEFGHIJKLMNOPQRSTUVWXYZ " + " abcdefghijklmnopqrstuvwxyz " + " 0123456789 " ;
4 static char [] src = ssource.toCharArray();
5
6
7 // 产生随机字符串
8
9 private static String randString ( int length) {
10 char [] buf = new char [length];
11 int rnd;
12 for ( int i = 0 ;i < length;i ++ ) {
13 rnd = Math.abs(r.nextInt()) % src.length;
14
15 buf[i] = src[rnd];
16 }
17 return new String(buf);
18 }
19
20 // 调用该方法，产生随机字符串,
21 // 参数i: 为字符串的长度
22 public String runVerifyCode( int i) {
23 String VerifyCode = randString(i);
24 return VerifyCode;
25 }
26
27
28 // 给定范围获得随机颜色
29 public Color getRandColor( int fc, int bc)
30 {
31 Random random = new Random();
32 if (fc > 255 ) fc = 255 ;
33 if (bc > 255 ) bc = 255 ;
34 int r = fc + random.nextInt(bc - fc);
35 int g = fc + random.nextInt(bc - fc);
36 int b = fc + random.nextInt(bc - fc);
37 return new Color(r,g,b);
38 }
39
40 // 调用该方法将得到的验证码生成图象
41 // sCode:传递验证码 w:图象宽度 h:图象高度
42 public BufferedImage CreateImage(String sCode)
43 {
44 try {
45 // 字符的字体
46 Font CodeFont = new Font( " Arial Black " ,Font.PLAIN, 16 );
47 int iLength = sCode.length(); // 得到验证码长度
48 int width = 22 * iLength, height = 20 ; // 图象宽度与高度
49 int CharWidth = ( int )(width - 24 ) / iLength; // 字符距左边宽度
50 int CharHeight = 16 ; // 字符距上边高度
51
52 // 在内存中创建图象
53 BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
54
55 // 获取图形上下文
56 Graphics g = image.getGraphics();
57
58 // 生成随机类
59 Random random = new Random();
60
61 // 设定背景色
62 g.setColor(getRandColor( 200 , 240 ));
63 g.fillRect( 0 , 0 , width, height);
64
65 // 设定字体
66 g.setFont(CodeFont);
67
68 // 画随机颜色的边框
69 g.setColor(getRandColor( 10 , 50 ));
70 g.drawRect( 0 , 0 ,width - 1 ,height - 1 );
71
72 // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
73 g.setColor(getRandColor( 160 , 200 ));
74 for ( int i = 0 ;i < 155 ;i ++ )
75 {
76 int x = random.nextInt(width);
77 int y = random.nextInt(height);
78 int xl = random.nextInt( 12 );
79 int yl = random.nextInt( 12 );
80 g.drawLine(x,y,x + xl,y + yl);
81 }
82
83
84 for ( int i = 0 ;i < iLength;i ++ )
85 {
86 String rand = sCode.substring(i,i + 1 );
87 // 将认证码显示到图象中
88 g.setColor( new Color( 20 + random.nextInt( 60 ), 20 + random.nextInt( 120 ), 20 + random.nextInt( 180 )));
89 g.drawString(rand,CharWidth * i + 14 ,CharHeight);
90 }
91 // 图象生效
92 g.dispose();
93 return image;
94 } catch (Exception e) {
95 // e.printStackTrace();
96 // System.out.println(e.getMessage());
97 }
98 return null ;
99 }
100
101 // 测试
102 public static void main(String[] args) {
103 // VerifyCode vc = new VerifyCode();
104 // String s1 = vc.runVerifyCode(4);
105 // Fun.DreamNewsTitle;System.out.println(s1);
106 // Image im = vc.CreateImage(s1);
107 // Graphics g = im.getGraphics();
108 // g.drawImage(im,20,20,this);
109 // g.drawString(s1,20,20);
110
111 }
112 }