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Spring Boot整合MyBatis

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我真菜

被Spring整合MyBatis打击到了，所以转向Spring Boot

我太菜了！！！

事先准备

一个User对象

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@Data		//lombok插件简单粗暴
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public class User {
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    private int userId;
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    private String username;
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    private String password;
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}

一张User表

字段名和属性名对应

接口处理

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public interface IUserMapper {
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    String getFirst();
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    User getById(int id);
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}

启动类上开启扫描

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@MapperScan("com.czw.springbootmybatis.mapper")

XML文件编写SQL语句并映射到接口(mapper标签的namespace)且对应接口方法名(id)

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<?xml version="1.0" encoding="UTF-8" ?>
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<!DOCTYPE mapper
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        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
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        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
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<mapper namespace="com.czw.springbootmybatis.mapper.IUserMapper">
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    <select id="getFirst" resultType="String">
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        select username from user where user_id = 1
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    </select>
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    <select id="getById" resultType="com.czw.springbootmybatis.bean.User">
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        select * from user where user_id = #{userId}
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    </select>
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</mapper>

配置文件

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#数据源配置
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spring.datasource.username=root
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spring.datasource.password=root
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spring.datasource.url=jdbc:mysql://localhost:3306/learningssm?serverTimezone=UTC
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#映射xml文件并实现下划线和大写转化
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mybatis.mapper-locations=classpath:mapper/*.xml 
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mybatis.configuration.map-underscore-to-camel-case=true

业务层

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@Service//存入IoC容器
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public class UserService {
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    @Autowired
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    private IUserMapper userMapper;
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    //自动注入
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    public String getFirst(){
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        return userMapper.getFirst();
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    }
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    //调用方法
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    public User getById(int id) {
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        return userMapper.getById(id);
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    }
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}

测试

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@Autowired
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UserService userService;
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//注入Service
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@Test
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void contextLoads() {
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    String str=userService.getFirst();
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    System.out.println(str);
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    User user=userService.getById(1);
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    System.out.println(user.toString());
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}

结果

可想而知

总结

头发-0，舒服了，Spring Boot真好