1. response.setHeader("Cache-Control","no-cache"); This is used to prevent the browser from caching your dynamic content generated by a JSP or Servlet. You set this attribute in the HTTP header of the response object which would tell
创建验证码的jsp页面提示错误:has already been called for this response <%@ page contentType="image/jpeg" %><%@ page import="java.awt.*,java.awt.image.*,java.util.*,javax.imageio.*"%><%!Color getRandColor(int fc,int bc){ //在确定的范围中获得随机