springboot 整合 mybatis 入门

springboot整合mybatis

0.yml 配置文件

1.创建数据库表。

2.创建实体类。

3.创建 Mapper 接口 ，添加 @Mapper 注解。

4.创建 Mapper 映射文件。

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.7.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <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>1.3.2</version>
    </dependency>

    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
    </plugins>
</build>

yml 配置文件

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/db2?serverTimezone=Asia/Shanghai
    username: root
    password: root

mybatis:
  type-aliases-package: com.mozq.boot.sbmybatis01.domain
  mapper-locations: classpath:mapper/*Mapper.xml

创建数据库表

use db2;

create table user(
	id int auto_increment,
	name varchar(50),
	password varchar(50),
	primary key(id)
) character set utf8;

insert into user values
(null, '刘备', 'liubei'),
(null, '孙权', 'sunquan'),
(null, '曹操', 'caocao');

创建实体类

package com.mozq.boot.sbmybatis01.domain;

public class User {
    private Integer id;
    private String name;
    private String password;
}

创建 Mapper 接口 使用 @Mapper 注解

package com.mozq.boot.sbmybatis01.mapper;

import com.mozq.boot.sbmybatis01.domain.User;
import org.apache.ibatis.annotations.Mapper;

import java.util.List;

@Mapper
public interface UserMapper {
    List<User> findAll();
}

创建 Mapper 映射文件

resources > 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.mozq.boot.sbmybatis01.mapper.UserMapper">

    <select id="findAll" resultType="User">
        select id, name, password
        from user
    </select>
</mapper>

测试 Mapper 接口

package com.mozq.boot.sbmybatis01.controller;

import com.mozq.boot.sbmybatis01.domain.User;
import com.mozq.boot.sbmybatis01.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserMapper userMapper;

    @RequestMapping("/findAll")
    public List<User> findAll(){
        List<User> userList = userMapper.findAll();
        return userList;
    }
}
/*
	运行结果：http://localhost:8080/user/findAll
	[{"id":1,"name":"刘备","password":"liubei"},{"id":2,"name":"孙权","password":"sunquan"},{"id":3,"name":"曹操","password":"caocao"}]
*/