Jsp+Servlet+Mysql简单的登录

图片

JSP:

 

         

             
                 
                   
                   
                 
                 
                   
                   
                 
                 
                   
                 
             

用户名:
密    码:

         

     

Servlet:

package com.syh.servlet;


import java.io.IOException;


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.syh.pojo.User;
import com.syh.service.UserService;


public class LoginServlet extends HttpServlet{


@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, IOException {
doPost(req, resp);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

//获取从jsp页面传过来的数据
String username = request.getParameter("username");
String password = request.getParameter("password");

//获取service对象，用来处理逻辑事务
UserService service = new UserService();

User user = new User();
user = service.findSimpleUser(username);
if(password != null && password != "" && password.equals(user.getPassword())){
HttpSession session = request.getSession();
session.setAttribute("user", user);
request.getRequestDispatcher("/success.jsp").forward(request, response);
}else{
request.getRequestDispatcher("/error.jsp").forward(request, response);
}
}
}

Service:

package com.syh.service;


import com.syh.dao.UserDao;
import com.syh.pojo.User;


public class UserService {


UserDao dao = new UserDao();


public User findSimpleUser(String username) {
return dao.findSimpleUser(username);
}


}

dao:

package com.syh.dao;


import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;


import com.syh.pojo.User;
import com.syh.utils.DataSourseUtil;


public class UserDao {


private DataSourseUtil util = null;
public User findSimpleUser(String username) {
String sql = "select * from user where  username = ?";
Map map = new HashMap();
List