[Spring Boot] Database persistence layer framework MyBatis — Spring Boot builds MyBatis applications

Spring Boot builds MyBatis application

Spring Boot is a framework for quickly building Spring applications. MyBatis is a Java persistence framework that helps developers manage databases easily. Using Spring Boot with MyBatis makes it easier for developers to create and manage database applications.

Here are the steps to build a MyBatis application using Spring Boot:

1. Add MyBatis dependencies: Add the following dependencies in the project's pom.xml file:

<dependency>
  <groupId>org.mybatis.spring.boot</groupId>
  <artifactId>mybatis-spring-boot-starter</artifactId>
  <version>2.2.0</version>
</dependency>

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

Introducing the MyBatis-spring-boot-starter component requires specifying the version number. In addition, the mysql-connector-java connection driver needs to be introduced.

2. Configure MyBatis: Add the following configuration in the application.properties file:

mybatis.mapper-locations=classpath:mapper/*.xml

This will tell MyBatis to look for the mapper folder on the classpath and use the XML file there.

3. Create MyBatis mapper interface: Create an interface that will define methods to operate on the database. For example:

@Mapper
public interface UserMapper {
    
    
  @Select("SELECT * FROM users WHERE id = #{id}")
  User findById(@Param("id") Long id);
}

This interface will define a findById method which will find a user with a given ID in the database.

4. Create a MyBatis XML mapper file: Create an XML file that will define the mapping relationship between database tables and Java classes. For example:

<mapper namespace="com.example.app.mapper.UserMapper">
  <resultMap id="userResultMap" type="com.example.app.model.User">
    <id property="id" column="id"/>
    <result property="name" column="name"/>
    <result property="email" column="email"/>
  </resultMap>

  <select id="findById" resultMap="userResultMap">
    SELECT * FROM users WHERE id = #{id}
  </select>
</mapper>

This XML file will define a findById query which will return users with a given ID.

5. Inject MyBatis mapper: Inject UserMapper in Spring Boot application and use it to perform database operations. For example:

@Service
public class UserService {
    
    
  @Autowired
  private UserMapper userMapper;

  public User findById(Long id) {
    
    
    return userMapper.findById(id);
  }
}

This UserService class will use UserMapper to perform database operations and return the results to the caller.

6. Run the application: Run the Spring Boot application and use UserService to find the user.

These are the basic steps to build a MyBatis application using Spring Boot. Database applications can be easily created and managed using Spring Boot and MyBatis.