JSP+JavaBean+Servlet的框架demo

package com.demo.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; import javax.servlet.http.HttpSession; import com.demo.javabean.UserBean; public class UserServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doGet(request, response); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String method = (String)request.getParameter("method"); if(method==null) { PrintWriter out = response.getWriter(); out.println("invalid request!"); } else if(method.equals("login")) { Login(request, response); } else if(method.equals("logout")) { Logout(request, response); } else if(method.equals("register")) { Register(request, response); } } protected void Login(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // get parameters String username = request.getParameter("username"); String password = request.getParameter("password"); // check null if (username == null || password == null) { response.sendRedirect("login.jsp"); return; } // validate UserBean userBean = new UserBean(); boolean isValid = userBean.valid(username, password); if (isValid) { HttpSession session = request.getSession(); session.setAttribute("username", username); response.sendRedirect("welcome.jsp"); return; } else { response.sendRedirect("login.jsp"); return; } } protected void Logout(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { HttpSession session = request.getSession(); session.removeAttribute("username"); response.sendRedirect("login.jsp"); } protected void Register(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // get parameters String username = request.getParameter("username"); String password1 = request.getParameter("password1"); String password2 = request.getParameter("password2"); String email = request.getParameter("email"); // check null if (username == null || password1 == null || password2 == null || !password1.equals(password2)) { response.sendRedirect("register.jsp"); return; } // validate UserBean userBean = new UserBean(); boolean isExist = userBean.isExist(username); if(!isExist) { userBean.add(username, password1, email); response.sendRedirect("login.jsp"); return; } else { response.sendRedirect("register.jsp"); return; } } }