【JavaWeb】(11)Java实现验证码制作

package com.thr.servlet; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class LoginServlet extends HttpServlet { /** * The doGet method of the servlet. <br> * * This method is called when a form has its tag value method equals to get. * * @param request * the request send by the client to the server * @param response * the response send by the server to the client * @throws ServletException * if an error occurred * @throws IOException * if an error occurred */ public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=utf-8"); String checkCode = (String) request.getSession().getAttribute( "check_code"); String userCode = (request.getParameter("check_code")).toUpperCase(); PrintWriter out = response.getWriter(); if (checkCode.equals(userCode)) { out.print("验证码输入正确"); } else { out.print("验证码输入错误"); } out.close(); } }