因为跨域 导致 session中的id不一致.
String captchaId = request.getSession().getId();
解决方案: 1.跨域后传送cookie,保持两个请求sessionid一致. 2.将生成的验证码存放到内存的缓存中. 然后验证就从缓存中对比. (近似验证) package com.hupun.console.dubbo.http.proxy.rest.controller; import com.bstek.common.log.Logger; import com.bstek.common.log.LoggerFactory; import java.awt.Color; import java.awt.Font; import java.awt.Graphics; import java.awt.image.BufferedImage; import java.util.Random; import javax.imageio.ImageIO; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; public class RandomValidateCode { private static Logger logger = LoggerFactory.getInstance().getLogger(RandomValidateCode.class); private Random random = new Random(); private String randString = "123456789ABCDEFGHIJKLMNPQRSTUVWXYZ"; // 随机产生的字符串 private int width = 80; // 图片宽 private int height = 26; // 图片高 private int lineSize = 40; // 干扰线数量 private int stringNum = 4; // 随机产生字符数量 /* * 获得字体 */ private Font getFont() { return new Font("Fixedsys", Font.CENTER_BASELINE, 18); } /* * 获得颜色 */ private Color getRandColor(int fc, int bc) { if (fc > 255) fc = 255; if (bc > 255) bc = 255; int r = fc + random.nextInt(bc - fc - 16); int g = fc + random.nextInt(bc - fc - 14); int b = fc + random.nextInt(bc - fc - 18); return new Color(r, g, b); } /** * 生成随机图片 */ public String getRandcode(HttpServletRequest request, HttpServletResponse response) { // HttpSession session = request.getSession(); // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类 String randomString = ""; try { BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR); Graphics g = image.getGraphics();// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作 g.fillRect(0, 0, width, height); g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18)); g.setColor(getRandColor(110, 133)); // 绘制干扰线 for (int i = 0; i <= lineSize; i++) { drowLine(g); } // 绘制随机字符 for (int i = 1; i <= stringNum; i++) { randomString = drowString(g, randomString, i); } // session.removeAttribute(Constant.RANDOMCODEKEY); // session.setAttribute(Constant.RANDOMCODEKEY, randomString); g.dispose(); ImageIO.setUseCache(false); ImageIO.write(image, "JPEG", response.getOutputStream());// 将内存中的图片通过流动形式输出到客户端 } catch (Exception e) { logger.error(e, "生成随机图片失败!"); } return randomString; } /* * 绘制字符串 */ private String drowString(Graphics g, String randomString, int i) { g.setFont(getFont()); g.setColor(new Color(random.nextInt(101), random.nextInt(111), random.nextInt(121))); String rand = String.valueOf(getRandomString(random.nextInt(randString.length()))); randomString += rand; g.translate(random.nextInt(3), random.nextInt(3)); g.drawString(rand, 13 * i, 16); return randomString; } /* * 绘制干扰线 */ private void drowLine(Graphics g) { int x = random.nextInt(width); int y = random.nextInt(height); int xl = random.nextInt(13); int yl = random.nextInt(15); g.drawLine(x, y, x + xl, y + yl); } /* * 获取随机的字符 */ public String getRandomString(int num) { return String.valueOf(randString.charAt(num)); } }