这篇主要介绍Springboot整合MybatisPlus，另外介绍一个插件JBLSpringbootAppGen,以及一个经常用于测试的基于内存的h2数据库。
Mybatisplus是mybatis的增强工具，和tk-mybatis相似，但功能更强大，可避免重复CRUD语句，先来一个简单入门：
1.安装一个插件：JBLSpringbootAppGen：
File->Setting->Plugin: 搜索点击Install,重启IDEA
这个工具主要用于创建启动类时自动创建配置文件。
2.新建一个modle: mybatis-plus-demo;
3.添加pom依赖：
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.lxj</groupId>
<artifactId>mybatis-plus-demo</artifactId>
<version>1.0-SNAPSHOT</version>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.0.RELEASE</version>
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<mybatisplus.version>3.3.2</mybatisplus.version>
<skipTests>true</skipTests>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency><!--基于内存的数据库-->
<groupId>com.h2database</groupId>
<artifactId>h2</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>${mybatisplus.version}</version>
</dependency>
<dependency><!--测试框架-->
<groupId>org.assertj</groupId>
<artifactId>assertj-core</artifactId>
<scope>test</scope>
</dependency>
<dependency><!--简化实体类开发，加@Data注解不用写get、set方法-->
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
</project>4.通过工具添加启动类：
5.设置配置项：（注意每一项冒号后面有个空格！）
自动创建的配置文件为yml，和properties文件比结构层级更清晰一些：
#Datasource Configspring:spring:
spring:
datasource:
driver-class-name: org.h2.Driver
schema: classpath:db/schema-h2.sql
data: classpath:db/data-h2.sql
#y用于测试可随便写
url: jdbc:h2:mem:test
username: roottest
passworld: test123
#Logger Config
logging:
level:
com.lxj.quickstart: debug6.引入测试用的数据库：
一个是创建表的sql文件：
DROP TABLE IF EXISTS user;
CREATE TABLE 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)
)一个是插入数据的sql文件：
DELETE FROM user;
INSERT INTO user (id,name,age,email) VALUES
(1,'Jone',18,'test1@abc.com'),
(2,'Jack',19,'test2@abc.com'),
(3,'Tom',20,'test3@abc.com'),
(4,'Sandy',18,'test4@abc.com'),
(5,'hahaha',19,'test5@abc.com'),
(6,'Billie',18,'test6@abc.com');
将两个文件放到classpath下：
7.编写实体类：
package com.lxj.quickstart.entity;
import lombok.Data;
@Data
public class User {
private Long id;
private String name;
private Integer age;
private String email;
}
@Data注解可给类中属性自动添加get/set方法。
8.编写dao类：
package com.lxj.quickstart.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.lxj.quickstart.entity.User;
public interface UserMapper extends BaseMapper<User> {
}
9.启动类中别忘了添加扫描包路径：
@MapperScan("com.lxj.quickstart.mapper")10.添加测试类测试：
package com.lxj.quickstart.mapper;
import com.lxj.quickstart.entity.User;
import org.junit.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 com.lxj.quickstart.mapper.UserMapper;
import java.util.List;
import static org.junit.Assert.*;
@RunWith(SpringRunner.class)
@SpringBootTest
public class UserMapperTest {
@Autowired
private UserMapper userMapper;
@Test
public void testSelect(){
List<User> list = userMapper.selectList(null);
list.forEach(System.out::println);
}
}11.结果：
