适合初学者-sprungboot+mybatis实现增删改查
springboot初识
（适合初学）springboot+mybatis实现增删改查
前言
开发工具及版本：
window10
idea-2018.2.2
maven-3.54
navicat
效果图
目录结构
springboot框架简介
数据库
demo数据库，表名users
pom.xml
通过Maven导入，不知道怎么配置maven可以自行百度
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.2.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>mybits</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>mybits</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- mysql -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.16</version>
</dependency>
<!-- freemarker模板引擎视图 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-freemarker</artifactId>
</dependency>
<!-- 热部署，不用重启 ，这个在这里不需要-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
</dependency>
<!-- jsp解析器 -->
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
对于一个项目，从发起到响应流程
controller层
Controller层：控制层 控制业务逻辑
具体的业务模块流程的控制，controller层主要调用Service层里面的接口控制具体的业务流程，控制的配置也要在配置文件中进行。
package com.example.mybits.Controller;
import com.example.mybits.Model.User;
import com.example.mybits.Service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.servlet.ModelAndView;
@Controller
//@RestController
public class UserController {
@Autowired
private UserService userService;
//查询所有
@RequestMapping("/selectUserAll")
public ModelAndView selectUserAll(){
ModelAndView mav = new ModelAndView("selectUserAll");
mav.addObject("user", userService.selectUserAll());
return mav;
}
//根据id查询用户
@RequestMapping("/selectUserById")
public ModelAndView selectUserById(Integer id){
ModelAndView mav = new ModelAndView("selectUserById");
mav.addObject("user",userService.selectUserById(id));
return mav;
}
//根据number查询用户
@RequestMapping("/selectUserByNumber")
public ModelAndView selectUserByNumber(String number){
ModelAndView mav = new ModelAndView("selectUserByNumber");
mav.addObject("user",userService.selectUserByNumber(number));
return mav;
}
//根据工号查询用户（name）
@RequestMapping("/selectUserByName")
public ModelAndView selectUserByName(String name){
ModelAndView mav = new ModelAndView("selectUserByName");
mav.addObject("user",userService.selectUserByName(name));
return mav;
}
//根据id删除用户
@RequestMapping("/deleteUserById")
public String deleteUser(Integer id){
userService.deleteUser(id);
return "redirect:selectUserAll";
}
//添加用户
@RequestMapping("/addUser")
public String addUser(User user){
userService.addUser(user);
return "redirect:selectUserAll";
}
@RequestMapping("/add")
public ModelAndView addController(User user){
ModelAndView mav = new ModelAndView();
mav.setViewName("add");
return mav;
}
//通过id显示修改内容
@RequestMapping("/selectOneById")
public ModelAndView selectOneById(int id){
ModelAndView mav = new ModelAndView("update");
mav.addObject("user", userService.selectOneById(id));
return mav;
}
//根据id修改用户
@RequestMapping("/updateUserById")
public String updateUserById(User user){
userService.updateUser(user);
return "redirect:selectUserAll";
}
}
dao层（持久层）
Dao层：持久层，主要是和数据库进行交互
dao层首先胡创建dao接口，接着就可以在配置文件中定义该接口的实现类；接着就可以在模块中调用dao的接口进行数据业务的处理，而不用关注此接口的具体实现是哪一个类，dao层的数据源和数据库实在配置文件中进行配置的。
UserDao接口：
package com.example.mybits.Dao;
import com.example.mybits.Model.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.data.jdbc.repository.query.Query;
import org.springframework.stereotype.Repository;
import java.util.List;
//@Repository
@Mapper
public interface UserDao {
void addUser(User user);
void deleteUser(Integer id);
void updateUser(User user);
List<User> selectUserAll();
List<User> selectUserById(int id);
User selectOneById(Integer id);
List<User> selectUserByNumber(String number);
List<User> selectUserByName(String name);
}
Mapper——userMapper.xml
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.mybits.Dao.UserDao">
<sql id="table">users</sql>
<resultMap id="BaseResultMap" type="com.example.mybits.Model.User" >
<id column="id" property="id" jdbcType="INTEGER" />
<result column="number" property="number" jdbcType="VARCHAR" />
<result column="name" property="name" jdbcType="VARCHAR" />
<result column="local" property="local" jdbcType="VARCHAR" />
<result column="ip" property="ip" jdbcType="VARCHAR" />
<result column="note" property="note" jdbcType="VARCHAR" />
</resultMap>
<insert id="addUser" parameterType="com.example.mybits.Model.User" useGeneratedKeys="true" keyProperty="id">
insert into users (id,number,name,local,ip,note) values (#{id}, #{number}, #{name}, #{local}, #{ip}, #{note})
</insert>
<delete id="deleteUser" parameterType="com.example.mybits.Model.User">
delete from users where id=#{id}
</delete>
<select id="selectUserAll" resultType="com.example.mybits.Model.User">
select * from users
</select>
<select id="selectUserById" resultType="com.example.mybits.Model.User">
select * from users where id like concat(concat('%',#{id}),'%');
</select>
<select id="selectOneById" resultType="com.example.mybits.Model.User">
select * from users where id like concat(concat('%',#{id}),'%');
</select>
<select id="selectUserByNumber" resultType="com.example.mybits.Model.User">
select * from users where number like concat(concat('%',#{number}),'%');
</select>
<select id="selectUserByName" resultType="com.example.mybits.Model.User">
select * from users where name like concat(concat('%',#{name}),'%');
</select>
<update id="updateUser" parameterType="com.example.mybits.Model.User">
update users set number=#{number}, name=#{name}, local=#{local}, ip=#{ip}, note=#{note} where id=#{id}
</update>
</mapper>
Model层
Mode层也称为po层和Entity层：实体层，数据库在项目中的类
主要用于定义与数据库对象的属性，提供get/set方法，带参和无参的构造方法。
User：
package com.example.mybits.Model;
public class User {
private Integer id;
private String number;
private String name;
private String local;
private String ip;
private String note;
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getNumber() {
return number;
}
public void setNumber(String number) {
this.number = number;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getLocal() {
return local;
}
public void setLocal(String local) {
this.local = local;
}
public String getIp() {
return ip;
}
public void setIp(String ip) {
this.ip = ip;
}
public String getNote() {
return note;
}
public void setNote(String note) {
this.note = note;
}
}
Service层
Service层：业务层控制业务
业务模块的逻辑应用设计，和DAO层一样都是先设计接口，再创建要实现的类，然后在配置文件中进行配置其实现的关联。接下来就可以在service层调用接口进行业务逻辑应用的处理。
好处：封装Service层的业务逻辑有利于业务逻辑的独立性和重复利用性。
UserService
package com.example.mybits.Service;
import com.example.mybits.Dao.UserDao;
import com.example.mybits.Model.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class UserService {
@Autowired
UserDao userDao;
public void addUser(User user){
userDao.addUser(user);
}
public void deleteUser(Integer id){
userDao.deleteUser(id);
}
public void updateUser(User user){
userDao.updateUser(user);
}
public List<User> selectUserAll(){
return userDao.selectUserAll();
}
public List<User> selectUserById(int id){
return userDao.selectUserById(id);
}
public User selectOneById(Integer id){
return userDao.selectOneById(id);
}
/**通过名字查询记录**/
public List<User> selectUserByNumber(String number){
return userDao.selectUserByNumber(new String(number));
}
/**通过职称查询记录**/
public List<User> selectUserByName(String name) {
return userDao.selectUserByName(new String(name));
}
}
MybitsApplication
package com.example.mybits;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
@MapperScan("com.example.mybits.Dao")
@SpringBootApplication
public class MybitsApplication extends SpringBootServletInitializer {
public static void main(String[] args) {
SpringApplication.run(MybitsApplication.class, args);
}
protected SpringApplicationBuilder config(SpringApplicationBuilder applicationBuilder){
return applicationBuilder.sources(MybitsApplication.class);
}
}
application.yml
application为配置文件，用 配置文件去覆盖 SpringBoot 的默认配置，可以在resources 文件夹下创建 application.yml文件，这里就以手动配置 Tomcat 端口去覆盖SpringBoot 默认配置为例，我们知道 Tomcat 默认打开端口是8080。
server:port: 8089
workname: sy
field: 111
spring:
datasource:
url: jdbc:mysql://localhost/demo?serverTimezone=GMT%2B8&characterEncoding=utf8&allowMultiQueries=true
username: root
password: 123456
driver-class-name: com.mysql.cj.jdbc.Driver
mvc:
view:
prefix: /WEB-INF/jsp/
suffix: .jsp
mybatis:
mapper-locations: classpath:Mapper/*.xml
type-aliases-package: com.example.mybits.Model
前端jsp页面（首页）
selectUserAll
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<head>
</head>
<body>
<div>
<form action="selectUserById" method="get">
<div align='center'><input type="text" name="id"><button type="submit">按照工号搜索</button>
<form action="selectUserByNumber" method="get"><div align='center'><input type="text" name="number"><button type="submit">按照姓名搜索</button></div></form>
<form action="selectUserByName" method="get"><div align='center'><input type="text" name="name"><button type="submit">按照职称搜索</button></div></form>
<a href="add"><button type="button">新增</button></a>
</div>
</form>
</div>
<table align='center' border='1' cellspacing='0'>
<thead>
<tr>
<th>工号</th>
<th>姓名</th>
<th>职称</th>
<th>行政区</th>
<th>IP</th>
<th>备注</th>
<th>操作</th>
</tr>
</thead>
<tbody>
<c:forEach items="${user}" var="user">
<tr>
<td>${user.id}</td>
<td>${user.number}</td>
<td>${user.name}</td>
<td>${user.local}</td>
<td>${user.ip}</td>
<td>${user.note}</td>
<td><a href="deleteUserById?id=${user.id}"><button>删除</button></a>
<a href="selectOneById?id=${user.id}"><button>修改</button></a>
</td>
</tr>
</c:forEach>
</tbody>
</table>
</body></html>
增加页面
add.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<head>
</head>
<body>
<div id="section">
<form action="addUser" method="post">
<table class="tab" align='center' border='1' cellspacing="0" cellpadding="0" width="500" height="200">
<tr>
<td>姓名:</td>
<td><input type="text" name="number" value="${user.number}"></td>
</tr>
<tr>
<td>职称:</td>
<td><input type="text" name="name" value="${user.name}"></td>
</tr>
<tr>
<td>行政区:</td>
<td><input type="text" name="local" value="${user.local}"></td>
</tr>
<tr>
<td>IP:</td>
<td><input type="text" name="ip" value="${user.ip}"></td>
</tr>
<tr>
<td>备注:</td>
<td><input type="text" name="note" value="${user.note}"></td>
</tr>
<tr>
<td></td>
<td><input type="submit" value="确认新增" ></td>
<a href="javascript:history.go(-1)"><button type="button">返回</button></a>
</tr>
</table>
</form>
</div>
</body>
</html>
查询页面
selectUserById(通过id查询)
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<head>
</head>
<body>
<%--<div align='center'><a href="javascript:history.go(-1)"><button>Back</button></a></div>--%>
<table align='center' border='1' cellspacing='0'>
<thead>
<tr>
<th>工号</th>
<th>姓名</th>
<th>职称</th>
<th>行政区</th>
<th>IP</th>
<th>备注</th>
<th>操作</th>
</tr>
</thead>
<tbody>
<c:forEach items="${user}" var="user">
<tr>
<td>${user.id}</td>
<td>${user.number}</td>
<td>${user.name}</td>
<td>${user.local}</td>
<td>${user.ip}</td>
<td>${user.note}</td>
<td><a href="deleteUserById?id=${user.id}"><button>删除</button></a>
<a href="selectOneById?id=${user.id}"><button>修改</button></a>
</td>
</tr>
</c:forEach>
</tbody>
<a href="javascript:history.go(-1)"><button type="button">返回</button></a></td>
</table>
</body>
</html>
selectUserByName（通过name查询）
<%--
Created by IntelliJ IDEA.
User: admin
Date: 2021/6/15
Time: 11:12
To change this template use File | Settings | File Templates.
--%>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<head>
</head>
<body>
<%--<div align='center'><a href="javascript:history.go(-1)"><button>Back</button></a></div>--%>
<table align='center' border='1' cellspacing='0'>
<thead>
<tr>
<th>工号</th>
<th>姓名</th>
<th>职称</th>
<th>行政区</th>
<th>IP</th>
<th>备注</th>
<th>操作</th>
</tr>
</thead>
<tbody>
<c:forEach items="${user}" var="user">
<tr>
<td>${user.id}</td>
<td>${user.number}</td>
<td>${user.name}</td>
<td>${user.local}</td>
<td>${user.ip}</td>
<td>${user.note}</td>
<td><a href="deleteUserById?id=${user.id}"><button>删除</button></a>
<a href="selectOneById?id=${user.id}"><button>修改</button></a>
</td>
</tr>
</c:forEach>
</tbody>
<a href="javascript:history.go(-1)"><button type="button">返回</button></a></td>
</table>
</body>
</html>
selectUserNumber(通过Number查询)
<%--
Created by IntelliJ IDEA.
User: admin
Date: 2021/6/15
Time: 11:12
To change this template use File | Settings | File Templates.
--%>
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<head>
</head>
<body>
<%--<div align='center'><a href="javascript:history.go(-1)"><button>Back</button></a></div>--%>
<table align='center' border='1' cellspacing='0'>
<thead>
<tr>
<th>工号</th>
<th>姓名</th>
<th>职称</th>
<th>行政区</th>
<th>IP</th>
<th>备注</th>
<th>操作</th>
</tr>
</thead>
<tbody>
<c:forEach items="${user}" var="user">
<tr>
<td>${user.id}</td>
<td>${user.number}</td>
<td>${user.name}</td>
<td>${user.local}</td>
<td>${user.ip}</td>
<td>${user.note}</td>
<td><a href="deleteUserById?id=${user.id}"><button>删除</button></a>
<a href="selectOneById?id=${user.id}"><button>修改</button></a>
</td>
</tr>
</c:forEach>
</tbody>
<a href="javascript:history.go(-1)"><button type="button">返回</button></a></td>
</table>
</body>
</html>
修改页面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<head>
</head>
<body>
<div id="section">
<form action="updateUserById" method="post">
<table class="tab" align='center' border='1' cellspacing="0" cellpadding="0" width="600" height="200">
<tr>
<td>工号:</td>
<td><input type="text" name="id" value="${user.id}"></td>
</tr>
<tr>
<td>姓名:</td>
<td><input type="text" name="number" value="${user.number}"></td>
</tr>
<tr>
<td>职称:</td>
<td><input type="text" name="name" value="${user.name}"></td>
</tr>
<tr>
<td>行政区:</td>
<td><input type="text" name="local" value="${user.local}"></td>
</tr>
<tr>
<td>IP:</td>
<td><input type="text" name="ip" value="${user.ip}"></td>
</tr>
<tr>
<td>备注:</td>
<td><input type="text" name="note" value="${user.note}"></td>
</tr>
<tr>
<td></td>
<td><input type="submit" value="确认修改" ></td>
<a href="javascript:history.go(-1)"><button type="button">返回</button></a></td>
</tr>
</table>
</form>
</div>
</body>
</html>
注意
1.项目命名中的mybatis书写有误，请自行修改
2.项目中表单命名，number表示名字，name表示职称，请自行修改