很好用的验证码

很好用的验证码 非常好用的验证码程序 // index.jsp页面 <%@ page contentType="text/html;charset=gbk"%> body> <

系统产生的认证码:	换一张
输入上面的认证码:

// image.jsp页面 <%@ page contentType="image/jpeg" pageEncoding="gbk" import="java.awt.*,java.awt.image.*,java.util.*,javax. imageio.*"%> <%!Color getRandColor(int fc, int 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); }%> <% //设置页面不缓存 response.setHeader("Pragma", "No-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); // 在内存中创建图象(图像显示的大小) int width = 60, height = 20; BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); // 获取图形上下文 Graphics g = image.getGraphics(); //生成随机类 Random random = 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("方正舒体", Font.PLAIN, 18));//Times New Roman //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 (int 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) String codeList = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234 567890"; String sRand = ""; for (int i = 0; i < 4; i++) { int a = random.nextInt(codeList.length() - 1); String rand = codeList.substring(a, a + 1); sRand += rand; // 将认证码显示到图象中 g.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); } // 将认证码存入SESSION session.setAttribute("rand", sRand); // 图象生效 g.dispose(); // 输出图象到页面 ImageIO.write(image, "JPEG", response.getOutputStream()); %> // check.jsp页面 <%@ page contentType="text/html; charset=gbk" language="java" import="java.sql.*" errorPage=""%> <% String rand = (String) session.getAttribute("rand"); String input = request.getParameter("verification"); %> 系统产生的认证码为: <%=rand%>
您输入的认证码为: <%=input%>

<% if (rand.equalsIgnoreCase(input)) { %> o(?_?)o Yes <% } else { %> o(,，,)o No <% } %> 效果图: