[javaEE] 三层架构案例-用户模块（二）

使用junit测试框架，测试查找用户和添加用户功能

com.tsh.test.xmlUserDaoTest

package com.tsh.test;


import org.junit.Test;

import com.tsh.dao.XmlUserDao;
import com.tsh.domain.User;
/**
 * 测试用例
 * @author taoshihan
 *
 */
public class xmlUserDaoTest {
    @Test
    public void testFindUserByUsername(){
        XmlUserDao dao=new XmlUserDao();
        User user= dao.findUserByUsername("taoshihan");
        System.out.println(user);
    }
    @Test
    public void testAddUser(){
        XmlUserDao dao=new XmlUserDao();
        User user=new User();
        user.setUsername("taoshihan");
        user.setPassword("123456");
        dao.addUser(user);
    }
}

在逻辑层service层中，抛出自定义异常

com.tsh.service.UserService

package com.tsh.service;

import com.tsh.dao.XmlUserDao;
import com.tsh.domain.User;
import com.tsh.exception.MsgException;
/**
 * 用户逻辑
 * @author taoshihan
 *
 */
public class UserService {
    /**
     * 用户注册
     * @param user
     * @throws MsgException
     */
    public void registerUser(User user) throws MsgException{
        //检查用户名是否存在
        XmlUserDao dao=new XmlUserDao();
        if(dao.findUserByUsername(user.getUsername())!=null){
            throw new MsgException("用户名已经存在");
        }
        dao.addUser(user);
    }
}

在jsp中使用el标签判断登陆状态

<%@ 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 PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>用户中心</title>
</head>
<body>
<h1>用户中心</h1>
<hr>
<c:if test="${sessionScope.user==null }">
    欢迎光临，游客！
    <a href="${pageContext.request.contextPath }/login.jsp">登陆</a>
    <a href="${pageContext.request.contextPath }/register.jsp">注册</a>
</c:if>
<c:if test="${sessionScope.user!=null }">
    欢迎光临，${sessionScope.user.username }！
    <a href="${pageContext.request.contextPath }/Servlet/logout">注销</a>
</c:if>
</body>
</html>

在Servlet中对发送过来的数据进行处理

com.tsh.web.LoginServlet

package com.tsh.web;

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


import com.tsh.dao.XmlUserDao;
import com.tsh.domain.User;

/**
 * 登陆处理
 */
public class LoginServlet extends HttpServlet {
    /**
     */
    public LoginServlet() {
        super();
    }

    /**
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.getWriter().write("sss");
    }

    /**
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html; charset=utf-8");
        String username=request.getParameter("username");
        String password=request.getParameter("password");
        if("".equals(username) || "".equals(password==null)){
            request.setAttribute("msg", "用户名和密码不能为空！");
            request.getRequestDispatcher("/login.jsp").forward(request, response);
            return ;
        }
        XmlUserDao dao=new XmlUserDao();
        User user=dao.findUserByUsername(username);
        
        if(user!=null && user.getPassword().equals(password)){
            request.getSession().setAttribute("user", user);
            response.getWriter().write("登陆成功！");
        }else{
            response.getWriter().write("用户名或密码错误");
        }
    }

}

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原文地址：https://www.cnblogs.com/taoshihan/p/5640936.html