小弟刚学了做验证码,可是想把产生的验证码放到seesion中可老是为空 ?求大神帮下response.setContentType("image/jpeg");
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
createImages image=new createImages();
ImageIO.write(image.createIamge(), "JPEG", response.getOutputStream());
HttpSession session=request.getSession();
String s=image.Rf;
session.setAttribute("shuzhi", s);
String im=(String)session.getAttribute("shuzi");
System.out.println("hhhhhhhhhh"+im);结果:hhhhhhhhhhnull
response.setHeader("Pragma", "No-cache");
response.setHeader("Cache-Control", "no-cache");
response.setDateHeader("Expires", 0);
createImages image=new createImages();
ImageIO.write(image.createIamge(), "JPEG", response.getOutputStream());
HttpSession session=request.getSession();
String s=image.Rf;
session.setAttribute("shuzhi", s);
String im=(String)session.getAttribute("shuzi");
System.out.println("hhhhhhhhhh"+im);结果:hhhhhhhhhhnull
String im=(String)session.getAttribute("shuzi");
System.out.println("hhhhhhhhhh"+im);你拼音错误 看到了么 少了一个 “h” 一个是 "shuzhi" 一个是 "shuzi"