mybatis-jpa

        <dependency>
            <groupId>com.littlenb</groupId>
            <artifactId>mybatis-jpa</artifactId>
            <version>2.2.0</version>
        </dependency>

<settings>
    <!-- default : false -->
		<setting name="mapUnderscoreToCamelCase" value="true" />
</settings>

<configuration>
    <plugins>
		<plugin interceptor="com.littlenb.mybatisjpa.rs.ResultTypePlugin">
		</plugin>
	</plugins>
</configuration>

@Entity
public class UserArchive {// <resultMap id="xxx" type="userArchive">

    @Id
    private Long userId;// <id property="id" column="id" />
                           
    /** default mapping rule is camel(Java Field) to underline(SQL Column) */
    private String userName;// <result property="username" column="user_name"/>

    /** enum type */
    @Enumerated(EnumType.ORDINAL)
    private SexEnum sex;// <result property="sex" column="sex" typeHandler=EnumOrdinalTypeHandler/>
    
     /** enum type,custom value */
     @CodeEnum(CodeType.INT)
     private PoliticalEnum political;// <result property="political" column="political" typeHandler=IntCodeEnumTypeHandler/>

    /** java field differ from sql column in name */
    @Column(name = "gmt_create")
    private Date createTime;// <result property="createTime" column="gmt_create"/>
}// </resultMap>

<!-- in xml,declare the resultType -->
<select id="selectById" resultType="userArchive">
	SELECT * FROM t_sys_user_archive WHERE id = #{id}
</select>

@Component
public class AnnotationStatementInit {

  @Autowired
  private SqlSessionFactory sqlSessionFactory;

  @PostConstruct
  public void init() {
    Configuration configuration = sqlSessionFactory.getConfiguration();
    KeyGenerator keyGenerator = new IdentityKeyGenerator(new MyIdGenerator());
    configuration.addKeyGenerator(Constant.DEFAULT_KEY_GENERATOR, keyGenerator);
    AnnotationStatementScanner annotationStatementScanner = new AnnotationStatementScanner.Builder()
        .configuration(configuration)
        .basePackages(new String[]{"com.littlenb.mybatisjpa.demo.mapper"})
        .annotationStatementRegistry(AnnotationStatementRegistry.getDefaultRegistry()).build();
    annotationStatementScanner.scan();
  }
}

@Mapper
@Repository
public interface UserUpdateMapper {

    @InsertDefinition(strategy = SelectorStrategy.IGNORE_NULL)
    int insert(User user);

    @UpdateDefinition(strategy = SelectorStrategy.IGNORE_NULL, where = " id = #{id}")
    int updateById(User user);
}

/**
* Definition a Generic Interface as BaseMapper 
*/
public interface IBaseMapper<T> {

    @InsertDefinition
    int insert(T t);
  
    @InsertDefinition(strategy = SelectorStrategy.IGNORE_NULL)
    int insertIgnoreNull(T t);
  
    @InsertDefinition(strategy = SelectorStrategy.CERTAIN)
    int insertCertain(Certainty<T> certainty);
  
    @UpdateDefinition
    int updateById(T t);
  
    @UpdateDefinition(strategy = SelectorStrategy.IGNORE_NULL)
    int updateByIdIgnoreNull(T t);
  
    @UpdateDefinition(strategy = SelectorStrategy.CERTAIN, where = " id = #{entity.id}")
    int updateByIdCertain(Certainty<T> certainty);

}

/**
* extends BaseMapper
*/
@Mapper
@Repository
public interface UserMapper extends IBaseMapper<User> {

}