Comprehensive Guide to Integrating MyBatis‑Plus with Spring Boot

This tutorial introduces MyBatis‑Plus, a powerful ORM plugin for Spring Boot users, and walks through a complete integration process.

1. Quick Start – Prepare a Spring Boot, Maven, JDK 1.8, MySQL environment and create the required database (UTF‑8 mb4 charset is recommended).

1.1 Dependency Preparation

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.5.0</version>
</dependency>

<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.27</version>
</dependency>

<!-- mybatis‑plus multi‑datasource -->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>dynamic-datasource-spring-boot-starter</artifactId>
    <version>3.5.0</version>
</dependency>

1.2 Configuration Preparation

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@EnableDiscoveryClient
@MapperScan("com.wjbgn.user.mapper")
@SpringBootApplication
public class RobNecessitiesUserApplication {
    public static void main(String[] args) {
        SpringApplication.run(RobNecessitiesUserApplication.class, args);
    }
}

Data source configuration (master‑slave example) and HikariCP pool settings are added under spring.datasource.dynamic in application.yml .

2. Usage

2.1 Entity Annotations – Example entity with @TableName , @TableId , @TableField and logical delete field isDelete .

@TableName("user")
public class UserDO {
    @TableId(value = "id", type = IdType.AUTO)
    private Long id;
    @TableField("nickname")
    private String nickname;
    @TableField("sex")
    private SexEnum sex;
    @TableField(value = "create_time", fill = FieldFill.INSERT)
    private LocalDateTime createTime;
}

2.2 CRUD – Service interface extends IService , implementation extends ServiceImpl , and mapper extends BaseMapper .

public interface IUserService extends IService
{}

public class UserServiceImpl extends ServiceImpl
implements IUserService {}

public interface UserMapper extends BaseMapper
{}

2.3 Pagination – Register MybatisPlusInterceptor with PaginationInnerInterceptor for MySQL.

@Configuration
@MapperScan("com.wjbgn.*.mapper*")
public class MybatisPlusConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

2.4 Logical Delete – Global config or @TableLogic on isDelete field.

mybatis-plus:
  global-config:
    db-config:
      logic-delete-field: isDelete
      logic-delete-value: 1
      logic-not-delete-value: 0

or

@TableLogic
private Integer isDelete;

2.5 Enum Mapping – Define enum implementing IEnum and use @JsonFormat for proper JSON output.

public enum SexEnum implements IEnum
{
    MAN(1, "男"),
    WOMAN(2, "女");
    private Integer code;
    private String name;
    // getters omitted
}

Configure typeEnumsPackage and a custom MybatisPlusPropertiesCustomizer to use MybatisEnumTypeHandler .

2.6 Automatic Field Filling – Implement MetaObjectHandler to set createTime and updateTime automatically.

@Component
public class MyMetaObjectHandler implements MetaObjectHandler {
    @Override
    public void insertFill(MetaObject metaObject) {
        this.strictInsertFill(metaObject, "createTime", LocalDateTime.class, LocalDateTime.now());
    }
    @Override
    public void updateFill(MetaObject metaObject) {
        this.strictUpdateFill(metaObject, "updateTime", LocalDateTime.class, LocalDateTime.now());
    }
}

2.7 Multi‑Datasource – Show master‑slave, multiple DB types, and mixed configurations using @DS annotation on classes or methods.

@DS("slave_1")
public class UserServiceImpl extends ServiceImpl
implements IUserService {
    @DS("master")
    public int saveUser(UserDO userDO) { /* ... */ }
}

3. Testing – Provide SQL to create the user table, a controller with endpoints for save, update, delete, list, and paginated list, and confirm that the service works as expected.

@RestController
@RequestMapping("/user")
public class UserController {
    @Autowired
    private IUserService userService;
    // /save, /update, /delete, /list, /page endpoints omitted for brevity
}

The article ends with a link to the full source code repository.