[spring - mybatis tip] MyBatis(iBatis)에서 Java Enum code custom typeHandler 사용하기

요즘에야 JPA - Hibernate를 많이 쓰는 추세라 이런 고민은 안하겠지만..

프로젝트는 spring - mybatis기반이고.. 객체 지향 설계를 하다보니 enum들은 많아지고

그렇다고 mybatis에서 기본 제공되는 EnumTypeHandler를 쓰자니 DB에 저장되는 값이 커지고..

뭐 그래서 암튼 enum 요소에 매핑되는 code값들을 db에 넣고 싶은데

이놈들을 코드값으로 넣고 빼고 하는건.. 아무래도 customizing이 필요함.

사용법은 아래처럼..

MediaEnumUtil.java

public class MediaEnumUtils {

   public static <T extends Enum<T> & CodeEnum> T getCodeEnum(Class<T> enumClass, String code) {
      return EnumSet.allOf(enumClass).stream()
            .filter(type -> type.getCode().equals(code))
            .findFirst()
            .orElseGet(null);
   }
}

CodeEnum.java

public interface CodeEnum extends Serializable{
   public String getCode();
   public Enum getEnumByCode(String code);
}

MediaTypeEnumHandler.java

public class MediaEnumTypeHandler<E extends Enum<E> & CodeEnum> extends BaseTypeHandler<E> {

   private Class<E> type;

   public MediaEnumTypeHandler(Class<E> type) {
      if (type == null) throw new IllegalArgumentException("Type argument cannot be null");
      this.type = type;
   }

   @Override
   public void setNonNullParameter(PreparedStatement ps, int i, E parameter, JdbcType jdbcType) throws SQLException {
      if (jdbcType == null) {
         ps.setString(i, parameter.getCode());
      } else {
         ps.setObject(i, parameter.getCode(), jdbcType.TYPE_CODE);
      }
   }

   public E getNullableResult(ResultSet rs, String columnName) throws SQLException {
      String s = rs.getString(columnName);
      return MediaEnumUtils.getCodeEnum(type, s);
   }

   @Override
   public E getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
      String s = rs.getString(columnIndex);
      return MediaEnumUtils.getCodeEnum(type, s);
   }

   @Override
   public E getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
      String s = cs.getString(columnIndex);
      return MediaEnumUtils.getCodeEnum(type, s);
   }

}

MediaResourceType.java

public enum MediaResourceType implements CodeEnum {

   IMAGE("I") {
      @Override public Enum getEnumByCode(String code) {
         return IMAGE;
      }
   },
   VIDEO("V") {
      @Override public Enum getEnumByCode(String code) {
         return VIDEO;
      }
   },
   LIVE("L") {
      @Override public Enum getEnumByCode(String code) {
         return LIVE;
      }
   };

   final private String code;

   private MediaResourceType(String code) {
      this.code = code;
   }

   public String getCode() {
      return code;
   }
}

sql.xml - 해당되는 컬럼에 typeHandler 사용한부분.

<resultMap id="resourceMap" type="com.tmoncorp.api.domain.entity.resource.MediaResource">
    <id column="resource_seqno" property="resourceSeqno" jdbcType="BIGINT"/>
    <result column="resource_tp" property="resourceType" jdbcType="VARCHAR" typeHandler="com.tmoncorp.api.domain.enums.MediaEnumTypeHandler"/>
    <result column="tp_seqno" property="typeSeqno" jdbcType="INTEGER"/>
    <result column="file_nm" property="fileName" jdbcType="VARCHAR"/>
    <result column="org_file_nm" property="orgFileName" jdbcType="VARCHAR"/>
    <result column="file_path" property="filePath" jdbcType="VARCHAR"/>
    <result column="file_url" property="fileUrl" jdbcType="VARCHAR"/>
</resultMap>

MediaResource.java - Enum으로 변수 선언한 부분.

public class MediaResource implements Serializable {

   protected Long resourceSeqno;
   protected String orgFileName;
   protected String fileName;
   protected Integer fileSize;
   protected Short width;
   protected Short height;
   protected String filePath;
   protected MediaResourceType resourceType;
   protected Integer typeSeqno;
   protected String fileUrl;

   // getter, setter
}