[Enum] AttributeConverter 구현

1. Enum Interface

import com.fasterxml.jackson.annotation.JsonValue;

public interface SampleEnum {
    @JsonValue
    String getCode();
}

다음과 같은 SampleEnum 이라는 인터페이스를 작성한다

 

2. Enum Class

import java.util.Arrays;
import java.util.NoSuchElementException;
import lombok.Getter;
import lombok.RequiredArgsConstructor;


@Getter
@RequiredArgsConstructor
public enum SampleType implements SampleEnum {
    SAMPLE_ONE("sample1"),
    SAMPLE_TWO("sample2");

    private final String code;
    
    public static SampleType fromCode(String code) {
        return Arrays.stream(SampleType.values())
        .filter(type -> type.getCode().equals(code))
        .findAny()
        .orElseThrow(() -> new NoSuchElementException("Wrong code"));
    }
}

SampleEnum 인터페이스를 상속받은 Enum 클래스 SampleType을 작성한다

 

3. AttributeConverter

import java.util.EnumSet;
import java.util.NoSuchElementException;
import javax.persistence.AttributeConverter;

public class SampleCodeConverter<E extends Enum<E> & SampleEnum> implements AttributeConverter<E, String> {

    private Class<E> eClass;
    
    protected SampleCodeConverter(Class<E> eClass) {
        this.eClass = eClass;
    }
    
    @Override
    public String convertToDatabaseColumn(E attribute) {
        return attribute.getCode();
    }
    
    @Override
    public E convertToEntityAttribute(String dbData) {
        return EnumSet.allOf(eClass).stream()
        .filter(e -> e.getCode().equals(dbData))
        .findAny()
        .orElseThrow(() -> new NoSuchElementException("Wrong Code"));
    }
}

SampleEnum 인터페이스에 대한 AttributeConverter를 구현한다

 

4. Enum Class AttributeConverter

import javax.persistence.converter

@Converter
public class SampleTypeConverter extends SampleCodeConverter<SampleType> {

    SampleTypeConverter() {
        super(SampleType.class);
    }
}

5. JPA 사용

import javax.persistence.Entity;

@Entity
public class SampleEntity {

    @Id
    private Long id;
    
    @Convert(converter=SampleTypeConverter.class)
    private SampleType sampleType;
 
    // 생략
}