学不会你来砍我！spring boot 整合 mybatis-plus

简介

mybatis-plus

MyBatis-Plus（简称 MP）是一个 MyBatis 的增强工具，在 MyBatis 的基础上只做增强不做改变，为简化开发、提高效率而生。现最新版本为 3.3.0

添加依赖 pom.xml

• 引入 Spring Boot Starter 父工程：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.2.6.RELEASE</version>
    <relativePath/>
</dependency>

• 引入 spring-boot-starter、spring-boot-starter-test、mybatis-plus-boot-starter、lombok、mysql 依赖：

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.3.0</version>
    </dependency>
    <!-- MySQL -->
	<dependency>
		<groupId>mysql</groupId>
		<artifactId>mysql-connector-java</artifactId>
	</dependency>
</dependencies>
		

配置

1. application.yml 或 application.properties 配置文件中添加 mysql数据库的相关配置：

spring: 
  datasource:
    username: root
    password: 123456
    url: jdbc:mysql://localhost:3306/8timer_test?useUnicode=true&characterEncoding=UTF-8&serverTimezone=Asia/Shanghai&allowMultiQueries=true&zeroDateTimeBehavior=CONVERT_TO_NULL
    driver-class-name: com.mysql.cj.jdbc.Driver

2. Spring Boot 启动类中添加 @MapperScan 注解：

/* @MapperScan
 * 作用：指定要变成实现类的接口所在的包，然后包下面的所有接口在编译之后都会生成相应的实现类
 * 添加位置：是在Springboot启动类上面添加，
 */
@MapperScan("cn.timer.api.dao") // 扫描的mapper
@SpringBootApplication
public class Application {
	public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}

代码

创建实体类

People

@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class People {
    private Integer id;
    private String name;
    private Integer age;
    private String hobby;
    private String motto;
}

创建Mapper类

public interface PeopleMapper extends BaseMapper<People> {

}

调试

@RunWith(SpringRunner.class)
@SpringBootTest
public class SampleTest {

    @Autowired
    private PeopleMapper peopleMapper;

	//查询
    @Test
    public void selectList() {
        System.out.println(("selectList start"));
        // peopleMapper.selectList(queryWrapper); 
        // queryWrapper 是 MP 提供的 实体对象封装操作类，为 null 则无条件查询
        List<People> peopleList = peopleMapper.selectList(null);
        Assert.assertEquals(6, userList.size());
        for (People people : peopleList) {
			System.out.println(people);
		}
    }

}

控制台

selectList start
People(id=1001, name=Cxk, age=18, hobby=打篮球, motto=鸡你太美1)
People(id=1002, name=Cxk, age=18, hobby=嘻哈, motto=鸡你太美2)
People(id=1003, name=Cxk, age=18, hobby=唱, motto=鸡你太美3)
People(id=1004, name=Cxk, age=18, hobby=跳, motto=鸡你太美4)
People(id=1005, name=Cxk, age=18, hobby=rap, motto=鸡你太美5)
People(id=1006, name=Cxk, age=18, hobby=鸡, motto=鸡你太美6)

CRUD

新增

People p1 = People.builder().name("Cxk").age(18).hobby("打篮球").motto("鸡你太美1").build();
peopleMapper.insert(p1);

删除

peopleMapper.deleteById(id)

查询

People p3 = peopleMapper.selectById(id)

修改

People p4 = People.builder().id(1).hobby("唱").motto("ccccc").build();
peopleMapper.updateById(p4);

更多API请看官网： Mybatis Plus

总结

• 整合简易
• 不需要写 SQL和 XML 就可以实现简单的 CRUD 功能
• 快速开发项目

补充

• 【三分钟学会】spring boot 整合swagger2(knife4j-UI升级版)
• eclipse-lombok插件

感谢

感谢您的阅读，有收获？希望兄弟姐妹三叔六婶大姨大妈阿公阿婆来个三连击，给更多的同学看到这篇文章，感谢

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