前台开发——处理用户的登录

在导航栏的header.jsp中的登录按钮进行处理：

<li><a href="${pageContext.request.contextPath }/user_login.jsp" >登录</a></li>

user_login.jsp给form表单一个链接的地址：

<form action="${pageContext.request.contextPath }/user_login" method="post"> 

在servlet层中加入一个servlet类，命名为：UserLoginServlet.java

定义两个变量：

String ue=request.getParameter("ue");
String password=request.getParameter("password");

在UserDao.java写入查询的语句，一个是根据用户名（username）查询，另一个是根据邮箱（email）查询：

public User selectByUsernamePassword(String username,String password) throws SQLException {
            
            QueryRunner r = new QueryRunner(DBUtil.getDataSource());
            String sql="select * from user where username=? and password=?";
            return r.query(sql, new BeanHandler<User>(User.class),username,password);
            
        }
        
public User selectByEmailPassword(String email,String password) throws SQLException {
            
            QueryRunner r = new QueryRunner(DBUtil.getDataSource());
            String sql="select * from user where  email=? and password=?";
            return r.query(sql, new BeanHandler<User>(User.class), email,password);
            
        }
        
        

在UserService.java中写入根据UserDao层查询出来的结果进行一个处理：

public User login(String ue,String password) {
        
        
            User user=null;
            try {
                user = uDao.selectByUsernamePassword(ue, password);
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        
        if(user!=null) {
            return user;
        }
    try {
        user=uDao.selectByEmailPassword(ue, password);
    } catch (SQLException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    if(user!=null)
    {
        return user;
    }
    return null;
        
    }
    
    

UserLoginServlrt.java中通过由service层中处理的结果从而获取数据，当登录失败时候的结果：

package com.guiyan.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.guiyan.model.User;
import com.guiyan.service.UserService;

/**
 * Servlet implementation class UserLoginServlet
 */
@WebServlet("/user_login")
public class UserLoginServlet extends HttpServlet {
    private UserService uService=new UserService();
    
    
    
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String ue=request.getParameter("ue");
        String password=request.getParameter("password");
        User user=uService.login(ue, password);
        if(user==null) {
            request.setAttribute("failMsg", "用户名、邮箱或者密码错误，请重新登录！！！");
            request.getRequestDispatcher("/user_login.jsp").forward(request, response);
        }
    }

}

数据库里的内容：

其登录失败的效果图：

 上图是登录失败的结果

 

处理登录成功后跳转到个人中心

最终效果：

 

 UserLoginServlet.java进行登录成功的处理：

package com.guiyan.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.guiyan.model.User;
import com.guiyan.service.UserService;

/**
 * Servlet implementation class UserLoginServlet
 */
@WebServlet("/user_login")
public class UserLoginServlet extends HttpServlet {
    
    private UserService uService = new UserService();

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String ue = request.getParameter("ue");
        String password = request.getParameter("password");
        User user = uService.login(ue, password);
        if(user==null) {
            request.setAttribute("failMsg", "用户名、邮箱或者密码错误，请重新登录!!!");
            request.getRequestDispatcher("/user_login.jsp").forward(request, response);
        }else {
            request.getSession().setAttribute("user", user);
            request.getRequestDispatcher("/user_center.jsp").forward(request, response);
        }
        
    }

}

user_center.jsp的创建：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>


<!DOCTYPE html>
<html>
<head>
    <title>个人中心</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
    <link type="text/css" rel="stylesheet" href="css/bootstrap.css">
    <link type="text/css" rel="stylesheet" href="css/style.css">
    <script type="text/javascript" src="js/jquery.min.js"></script>
    <script type="text/javascript" src="js/bootstrap.min.js"></script>
    <script type="text/javascript" src="js/simpleCart.min.js"></script>
</head>
<body>

    





    <!--header-->
    <jsp:include page="/header.jsp"></jsp:include>
    
    
    <!--//header-->

    
    <!--account-->
    <div class="account">
        <div class="container">
            <div class="register">
                
                <form action="my.action" method="post"> 
                    <input type="hidden" name="user.id" value="1">
                    <div class="register-top-grid">
                        <h3>个人中心</h3>
                        
                        <h4>收货信息</h4>
                        <div class="input">
                            <span>收货人<label></label></span>
                            <input type="text" name="user.name" value="${user.name }" placeholder="请输入收货"> 
                        </div>
                        <div class="input">
                            <span>收货电话</span>
                            <input type="text" name="user.phone" value="${user.phone }" placeholder="请输入收货电话"> 
                        </div>
                        <div class="input">
                            <span>收货地址</span>
                            <input type="text" name="user.address" value="${user.address }" placeholder="请输入收货地址"> 
                        </div>
                        <div class="register-but text-center">
                           <input type="submit" value="提交">
                        </div>    
                        <hr>
                        <h4>安全信息</h4>
                        <div class="input">
                            <span>原密码</span>
                            <input type="password" name="user.password" placeholder="请输入原密码"> 
                        </div>
                        <div class="input">
                            <span>新密码</span>
                            <input type="password" name="user.passwordNew" placeholder="请输入新密码"> 
                        </div>
                        <div class="clearfix"> </div>
                        <div class="register-but text-center">
                           <input type="submit" value="提交">
                        </div>    
                    </div>
                </form>
                <div class="clearfix"> </div>
            </div>
        </div>
    </div>
    <!--//account-->

    




    <!--footer-->
    <jsp:include page="/footer.jsp"></jsp:include>
    <!--//footer-->

</body>
</html>