第三天：实现简单的添加和删除功能
实现用户管理系统的添加和删除用户信息功能
- 开发环境
- 具体实现
- .java文件
- .xml文件
- .jsp文件
- 运行界面
开发环境
- 64位的Windows系统
- Server version: 5.5.58
- MySQL Community Server (GPL)
- java version “1.8.0_211”
- SQLyog
- IDEA
- Apache Maven 3.6.0
具体实现
.java文件
//UserDao.java
package com.ldb.dao;
import com.ldb.bean.User;
import java.util.List;
//UserDao -- 数据库交互层
public interface UserDao {
//查询全部; ListUser user = new ArrayList<>()
List<User> findAllUser();
//添加用户
int save(User user);
//删除用户
int delete(User user);
}
//UserService.java
package com.ldb.service;
import com.ldb.bean.User;
import java.util.List;
//业务逻辑层
public interface UserService {
// 查询全部
List<User> findAllUser();
//添加用户
int save(User user);
//删除用户
int delete(User user);
}
//UserServiceImpl.java
package com.ldb.service.impl;
import com.ldb.bean.User;
import com.ldb.dao.UserDao;
import com.ldb.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
//Spring通过扫描注解来控制每个层，告诉Spring这里是service层
public class UserServiceImpl implements UserService {
@Autowired
//自动注入注解
private UserDao userDao;
@Override
//查询全部
public List<User> findAllUser() {
return userDao.findAllUser();
}
@Override
//添加用户
public int save(User user) {
return userDao.save(user);
}
//删除用户
public int delete(User user){
return userDao.delete(user);
}
}
//UserController.java
package com.ldb.controller;
import com.ldb.bean.User;
import com.ldb.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import java.util.List;
@Controller
@RequestMapping("/user")
//RequestMapping地址映射器，所有访问controller层都会访问这个地址，"/user"(根目录路径)指当前地址
public class UserController {
@Autowired
//controller层需要访问service层
private UserService userService;
private int num;
//查询全部用户
@RequestMapping("/findAllUser.do")
//所有需要返回数据到页面的，全部都要放在ModelAndView中返回
public ModelAndView findAllUser(){
//1. 调用service方法查询并得到结果
List<User> userList = userService.findAllUser();
//2. 实例化ModelAndView
ModelAndView mv = new ModelAndView();
//3. 接受数据
mv.addObject("userList", userList);
//4. 返回数据到页面，已经在spring-mvc.xml文件中的视图的解析器中添加了文件的前缀/jsp/和后缀.jsp
mv.setViewName("allUser");
return mv;
}
//添加用户
@RequestMapping("/toAddUser.do")
public String toAddUser(){
return "addUser";
}
@RequestMapping("/save.do")
public ModelAndView save(User user){
userService.save(user);
return findAllUser();
}
//删除用户
@RequestMapping("/delete.do")
public ModelAndView delete(User user){
userService.delete(user);
return findAllUser();
}
}
.xml文件
UserMapper.xml
<mapper namespace="com.ldb.dao.UserDao" >
<select id="findAllUser" resultType="com.ldb.bean.User">
select * from tb_user
select>
<insert id="save" parameterType="com.ldb.bean.User">
insert into tb_user value (#{id}, #{username}, #{password})
insert>
<delete id="delete" parameterType="com.ldb.bean.User">
delete from tb_user where id = #{id}
delete>
mapper>
.jsp文件
//显示所有用户界面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" isELIgnored="false"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>user列表</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<!-- 引入 Bootstrap -->
<link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
<div class="container">
<div class="row clearfix">
<div class="col-md-12 column">
<div class="page-header">
<h1>
基于SSM框架的管理系统：简单实现增、删、改、查。
</h1>
</div>
</div>
</div>
<div class="row clearfix">
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small>用户列表 —— 显示所有用户</small>
</h1>
</div>
</div>
</div>
<div class="row">
<div class="col-md-4 column">
<a class="btn btn-primary" href="${pageContext.request.contextPath}/user/toAddUser.do">新增</a>
</div>
</div>
<div class="row clearfix">
<div class="col-md-12 column">
<table class="table table-hover table-striped">
<thead>
<tr>
<th>id</th>
<th>用户名</th>
<th>密码</th>
<th>操作</th>
</tr>
</thead>
<tbody>
<c:forEach items="${userList}" var="userInfo">
<tr>
<td>${userInfo.id}</td>
<td>${userInfo.username}</td>
<td>${userInfo.password}</td>
<td>
<a href="${pageContext.request.contextPath}/user/toUpdate.do?id=${userInfo.id}">更改</a> |
//删除功能按键
<a href="${pageContext.request.contextPath}/user/delete.do?id=${userInfo.id}">删除</a>
</td>
</tr>
</c:forEach>
</tbody>
</table>
</div>
</div>
</div>
//addUser.jsp
//添加用户界面
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8" isELIgnored="false"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head>
<title>新增用户</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<!-- 引入 Bootstrap -->
<link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
<div class="container">
<div class="row clearfix">
<div class="col-md-12 column">
<div class="page-header">
<h1>
基于SSM框架的管理系统：简单实现增、删、改、查。
</h1>
</div>
</div>
</div>
<div class="row clearfix">
<div class="col-md-12 column">
<div class="page-header">
<h1>
<small>新增用户</small>
</h1>
</div>
</div>
</div>
<form action="${pageContext.request.contextPath}/user/save.do"
method="post">
用 户 id：<input type="text" name="id"><br><br><br>
用户姓名：<input type="text" name="username"><br><br><br>
用户密码：<input type="text" name="password"><br><br><br>
<input type="submit" value="添加" >
</form>
</div>
运行界面
添加用户界面，输入完成点击添加按钮，自动跳转到全部用户界面
点击删除选项，自动删除该项并刷新显示全部用户界面
