基于jsp+servlet的javaweb实现最基本的用户注册登陆注销功能

package cn.javabs.login.controller; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.lang3.StringUtils; import cn.javabs.login.entity.User; import cn.javabs.login.service.UserService; import cn.javabs.login.service.impl.UserServiceImpl; /** * * @author Mryang StringUtilsz中的isNotbBlock：判断某字符串是否不为空且长度不为0且不由空白符构成 * */ public class UserServlet extends HttpServlet { private static final long serialVersionUID = 1L; // 引入UserService UserService userService = new UserServiceImpl(); protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String method = request.getParameter("method"); // 如果传入的参数是login if ("login".equals(method)) { login(request, response); // 如果传入的参数是regist } else if ("regist".equals(method)) { regist(request, response); // 如果传入的参数是logout } else if ("logout".equals(method)) { logout(request, response); // 如果传入的参数是tologin } else if ("tologin".equals(method)) { tologin(request, response); // 如果传入的参数是toregist } else if ("toregist".equals(method)) { toregist(request, response); // 如果传入的参数是对应不上 } else { request.setAttribute("msg", "该功能正在开发..."); request.getRequestDispatcher("/message.jsp").forward(request, response); } } /** * 用户登录 * * @param request * @param response */ private void login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { /* * 1. 获取前台jsp表单传递的参数 */ String username = request.getParameter("username"); String password = request.getParameter("password"); // 如果测试传入的参数。可以打开72行的注释 // System.out.println("用户名：" + username + "<br/>" + "密码" + password); /* * 2.根据参数进行判断 */ // 2.1 如果用户名和密码都不为空 if (StringUtils.isNotBlank(username) && StringUtils.isNotBlank(password)) { // 2.1.1 传递到service层登录方法 User user = userService.userLogin(username, password); // 2.1.2 判断用户信息是否查询到 if (user != null) { // 查询到，存入session request.getSession().setAttribute("USER_SESSION", user); // 登录成功，转向主页 request.getRequestDispatcher("/WEB-INF/jsp/main.jsp").forward( request, response); } else { // 未查询到或者用户名和密码不匹配，将失败的信息存储到msg中 request.setAttribute("msg", "用户名或者密码不对！"); // 登录失败，转向错误信息提示页面，根据存入的msg取出相对应的内容 request.getRequestDispatcher("/message.jsp").forward(request, response);// } // 2.2 如果用户名或者密码为空 } else { request.setAttribute("msg", "用户名或者密码不许为空！"); request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward( request, response);// } } /** * 用户注册 * * @param request * @param response * @throws ServletException * @throws IOException */ private void regist(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { User user = new User(); // 1. 获取前台jsp页面的参数 String username = request.getParameter("username"); String password = request.getParameter("password"); String sex = request.getParameter("sex"); String email = request.getParameter("email"); // 2. 将获取到的参数封装到user对象中去 user.setUsername(username); user.setPassword(password); user.setEmail(email); user.setSex(sex); if (StringUtils.isNotBlank(user.getUsername()) && StringUtils.isNotBlank(user.getPassword())) { int rows = userService.userRegister(user); if (rows > 0) { response.setHeader("refresh", "1;url=UserServlet?method=tologin"); } else { request.setAttribute("msg", "注册失败！"); request.getRequestDispatcher("/message").forward(request, response); } }else{ request.setAttribute("msg", "用户名或者密码不许为空"); request.getRequestDispatcher("/message").forward(request, response); } } /** * 转向到登录页面 * * @param request * @param response * @throws ServletException * @throws IOException */ private void tologin(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward(request, response);// } /** * 转向到注册页面 * * @param request * @param response * @throws ServletException * @throws IOException */ private void toregist(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.getRequestDispatcher("/WEB-INF/jsp/regist.jsp").forward( request, response);// } /** * 用户注销 * @param request * @param response * @throws ServletException * @throws IOException */ private void logout(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.getSession().invalidate(); request.getRequestDispatcher("/WEB-INF/jsp/login.jsp").forward( request, response);// } }