login.java

JSP+servlet 登陆注册模块还可以进行信息的修改

package com.weishuang.servlet;

import java.io.IOException;

import javax.servlet.RequestDispatcher;
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.weishuang.dao.UserDAO;
import com.weishuang.pojo.Message;
import com.weishuang.pojo.User;
import com.weishuang.util.StringEncoder;

/**
 * Servlet implementation class Login
 */
public class Login extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Login() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		String username=StringEncoder.encode(request.getParameter("username"));
		String password=request.getParameter("password");
		boolean loginSuccess=false;
		UserDAO dao=new UserDAO();
		User u=(User)dao.queryUser(username, password);
		String success="index.jsp";
		String back="login.jsp";
		if(u!=null){
			loginSuccess=true;
			HttpSession session=request.getSession();
			session.setAttribute("user", u);
//			response.sendRedirect(success);
			RequestDispatcher rd=request.getRequestDispatcher(success);
			rd.forward(request, response);
			return ;
		}
		else{
			loginSuccess=false;
			Message msg=new Message();
			msg.setMsg("用户名或密码不正确");
			request.setAttribute("error",msg );
			RequestDispatcher rd=request.getRequestDispatcher(back);
			rd.forward(request, response);
//			response.sendRedirect(back);
			return ;
		}
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		this.doGet(request, response);
	}

}