JavaWeb实现servlet登录

package com.wyw.text.servlet; import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import com.wyw.text.Dao.UserDao; import com.wyw.text.Dao.impl.UserDaoimpl; import com.wyw.text.domin.User; @WebServlet("/loginservlet") public class loginservlet extends HttpServlet { private static final long serialVersionUID = 1L; public loginservlet() { super(); // TODO Auto-generated constructor stub } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.getWriter().append("Served at: ").append(request.getContextPath()); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/heml;charset=utf-8"); request.setCharacterEncoding("utf-8"); String username=request.getParameter("username"); String password=request.getParameter("password"); UserDao userDao=new UserDaoimpl(); User user=userDao.addfind(username, password); if(user==null){ request.setAttribute("pwd", "用户名或者密码错误"); request.getRequestDispatcher("/login.jsp").forward(request,response); return ; }else{ request.getSession().setAttribute("user", user); response.sendRedirect(request.getContextPath()+"/index.jsp"); return ; } } }