验证码的实验

1、public class VerifyCode private String sRand = ; protected String sNode =AaBbCcDdEeFfGgHhIiJjKkLlMmNnOoPpQqRrSsTtUuVvWwXxYyZz; protected String sFonts = new StringTimes New Roman,Comic Sans MS,华文行楷, MS Mincho,Gungsuh,Sylfaen,Arial, Franklin Gothic Medium,Century; public Color getRandColor(int fc, in

2、t bc) / 给定范围获得随机颜色 Random random = new Random(); if (fc 255) fc = 255; if (bc 255) bc = 255; int r = fc + random.nextInt(bc - fc); int g = fc + random.nextInt(bc - fc); int b = fc + random.nextInt(bc - fc); return new Color(r, g, b); public BufferedImage creatImage() / 在内存中创建图象 int width = 80, heigh

3、t = 20; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); / 获取图形上下文 /Graphics g = image.getGraphics(); Graphics2D g = image.createGraphics(); AffineTransform tx =new AffineTransform(); /调整字体变形,可以产生效果,但不理想 /tx.scale(1.2, 0.9); g.transform(tx); / 生成随机类 Random random =

4、 new Random(); / 设定背景色 g.setColor(getRandColor(200, 250); g.fillRect(0, 0, width, height); / 设定字体 g.setFont(new Font(this.getCurrentFonts(), Font.PLAIN, 18); / 画边框 / g.setColor(new Color(); / g.drawRect(0,0,width-1,height-1); / 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 g.setColor(getRandColor(160, 200); for (i

5、nt i = 0; i 155; i+) int x = random.nextInt(width); int y = random.nextInt(height); int xl = random.nextInt(12); int yl = random.nextInt(12); g.drawLine(x, y, x + xl, y + yl); / 取随机产生的认证码(4位数字) for (int i = 0; i =50) ii=50; else rand = String.valueOf(random.nextInt(10); sRand += rand; / 将认证码显示到图象中 g

6、.setColor(new Color(20 + random.nextInt(110), 20 + random .nextInt(110), 20 + random.nextInt(110); /调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成 g.drawString(rand, 13 * i + 6, 16); / 图象生效 g.dispose(); return image; public String getSRand() return sRand; public void setSRand(String rand) sRand = rand; /* * 随机产生是数

7、字还是字符 */ public boolean getRandomBoolResult() int i =(int) (Math.round(Math.random() * 4) ); if(i%2=0) return true; return false; 二使用方法public class VerifyCodeAction extends Action Override public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletRes

8、ponse response) throws Excep tion VerifyCode verify = new VerifyCode(); /获得一个实例 response.setHeader(Pragma, No-cache); /设置头属性 response.setHeader(Cache-Control, no-cache); response.setDateHeader(Expires, 0); BufferedImage buffImage = verify.creatImage(); /得到验证码图片 HttpSession session = request.getSession(true); session.setAttribute