因爲跨域 導致 session中的id不一致.
String captchaId = request.getSession().getId();
解決方案: 1.跨域後傳送cookie,保持兩個請求sessionid一致. 2.將生成的驗證碼存放到內存的緩存中. 然後驗證就從緩存中對比. (近似驗證) 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"; // 隨機產生的字符串 private int width = 80; // 圖片寬 private int height = 26; // 圖片高 private int lineSize = 40; // 干擾線數量 private int stringNum = 4; // 隨機產生字符數量 /* * 獲得字體 */ private Font getFont() { return new Font("Fixedsys", Font.CENTER_BASELINE, 18); } /* * 獲得顏色 */ 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); } /** * 生成隨機圖片 */ public String getRandcode(HttpServletRequest request, HttpServletResponse response) { // HttpSession session = request.getSession(); // BufferedImage類是具有緩衝區的Image類,Image類是用於描述圖像信息的類 String randomString = ""; try { BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR); Graphics g = image.getGraphics();// 產生Image對象的Graphics對象,改對象可以在圖像上進行各種繪製操作 g.fillRect(0, 0, width, height); g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18)); g.setColor(getRandColor(110, 133)); // 繪製干擾線 for (int i = 0; i <= lineSize; i++) { drowLine(g); } // 繪製隨機字符 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());// 將內存中的圖片通過流動形式輸出到客戶端 } catch (Exception e) { logger.error(e, "生成隨機圖片失敗!"); } return randomString; } /* * 繪製字符串 */ 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; } /* * 繪製干擾線 */ 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); } /* * 獲取隨機的字符 */ public String getRandomString(int num) { return String.valueOf(randString.charAt(num)); } }