整合 idea + SpringBoot + MybatisPlus

环境 idea 2020.3 + SpringBoot 2.4.1 + MybatisPlus 3.4.1 + MysqL 5.6

• 【第一步】新建一个 SpringBoot 工程。
• 【第二步】将 Maven 更换为阿里云仓库。

<!-- 修改 maven 根目录下的 conf 文件夹中的 setting.xml 文件 -->
<mirrors>
    <mirror>
      <id>alimaven</id>
      <name>aliyun maven</name>
      <url>http://maven.aliyun.com/nexus/content/groups/public/</url>
      <mirrorOf>central</mirrorOf>        
    </mirror>
</mirrors>

<!-- 配置pom.xml 文件 -->
<repositories>  
        <repository>  
            <id>alimaven</id>  
            <name>aliyun maven</name>  
            <url>http://maven.aliyun.com/nexus/content/groups/public/</url>  
            <releases>  
                <enabled>true</enabled>  
            </releases>  
            <snapshots>  
                <enabled>false</enabled>  
            </snapshots>  
        </repository>  
</repositories>

• 【第三步】pom 文件导入依赖

<!-- MybatisPlus 依赖 -->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.1</version>
</dependency>

<!-- MysqL 依赖 -->
<dependency>
    <groupId>MysqL</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

<!-- lombok 依赖 -->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>

• 【第四步】配置 yaml 文件

MysqL 配置

spring:
  datasource:
    driver-class-name: com.MysqL.cj.jdbc.Driver
    # 配置时区： serverTimezone=GMT%2B8 表示北京时间，UTC 表示全球标准时间，比北京晚了 8 小时。
    # 是否指定 SSL连接： useSSL=false 表示不使用。
    url: jdbc:MysqL://localhost:3306/cooper_mybatisplus?useSSL=false&useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8
    username: root
    password: MysqL123

• 【第五步】MysqL 数据库中创建 sys_user 表。

-- 创建数据库 cooper_mybatisplus ，默认字符集 latin1
CREATE DATABASE IF NOT EXISTS cooper_mybatisplus DEFAULT CHARSET utf8 COLLATE utf8_general_ci;

-- 创建数据表 sys_user
CREATE TABLE `sys_user` (
    `id` BIGINT(20) NOT NULL COMMENT '主键ID',
    `name` VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
    `age` INT(11) NULL DEFAULT NULL COMMENT '年龄',
    `email` VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
    PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='用户表';

-- 添加数据源
INSERT INTO sys_user (id, name, age, email) VALUES
(1, 'Jone', 18, '[email protected]'),
(2, 'Jack', 20, '[email protected]'),
(3, 'Tom', 28, '[email protected]'),
(4, 'Sandy', 21, '[email protected]'),
(5, 'Billie', 24, '[email protected]');

• 【第六步】创建 JavaBean ，任务就是: Write once, run anywhere, reuse everywhere

package com.example.cooper_mybatisplus.sys.pojo.entity;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

@Data
@TableName("sys_user")
public class SysUserEntity {
    private Long id;
    private String name;
    private Integer age;
    private String email;
}

• 【第七步】创建 Mapper

package com.example.cooper_mybatisplus.sys.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.cooper_mybatisplus.sys.pojo.entity.SysUserEntity;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface SysUserMapper extends BaseMapper<SysUserEntity> {
}

• 【第八步】测试

package com.example.cooper_mybatisplus;
import com.example.cooper_mybatisplus.sys.mapper.SysUserMapper;
import com.example.cooper_mybatisplus.sys.pojo.entity.SysUserEntity;
import org.junit.Assert;
import org.junit.jupiter.api.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBoottest;
import org.springframework.test.context.junit4.springrunner;
import java.util.List;

@RunWith(springrunner.class)
@SpringBoottest
class CooperMybatisplusApplicationTests {
    @Autowired
    private SysUserMapper sysUserMapper;

    @Test
    public void testSelect() {
        System.out.println(("----- selectAll method test ------"));
        List<SysUserEntity> userList = sysUserMapper.selectList(null);
        Assert.assertEquals(5, userList.size());
        userList.forEach(System.out::println);
    }
}

• 控制台输出

SysUserEntity(id=1, name=Jone, age=18, [email protected])
SysUserEntity(id=2, name=Jack, age=20, [email protected])
SysUserEntity(id=3, name=Tom, age=28, [email protected])
SysUserEntity(id=4, name=Sandy, age=21, [email protected])
SysUserEntity(id=5, name=Billie, age=24, [email protected])