@Enumerated(Enumtype.STRING) Hibernate JPA

Question

I have the following field classificacao in a table.

This field is filled in elsewhere and is filled with, only, 'P' or 'N', acronyms for Positive and Negative.

I then created the enum Java.

Classificacao.

public enum Classificacao {
    POSITIVO('P'), NEGATIVO('N');

    private char classificacao;

    Classificacao(char classificacao) {
        this.classificacao = classificacao;
    }

    public char getClassificacao() {
        return classificacao;
    }
}

In my entity, I have the attribute:

@Enumerated(EnumType.STRING)
@Convert(converter = ClassificacaoEnumConverter.class)
@Column(name = "classificacao", length = 1)
private Classificacao classificacao;

When I try to list this table, the following Exception is launched:

java.lang.IllegalArgumentException: Unknown name value [N] for enum class [br.com.jpalab.enums.Classificacao]

I understand why, from his mistake, he seeks the value N, where there is only POSTIVO and NEGATIVO, but how could I solve this problem?

I created this Converter

@Converter
public class ClassificacaoEnumConverter implements AttributeConverter<Classificacao, String> {

    @Override
    public String convertToDatabaseColumn(Classificacao classificacao) {
        return String.valueOf(classificacao.getClassificacao());
    }

    @Override
    public Classificacao convertToEntityAttribute(String classificacaoFromDb) {
        if (classificacao == null) return null;
        switch (classificacaoFromDb) {
            case "P":
                return Classificacao.POSITIVO;
            case "N":
                return Classificacao.NEGATIVO;
        }

        throw new IllegalStateException();
    }
}

Answer 1

Try using a Converter with a AttributeConverter:

import javax.persistence.AttributeConverter;
import javax.persistence.Converter;

public enum Classificacao {
    POSITIVO('P'), NEGATIVO('N');

    private final char classificacao;

    Classificacao(char classificacao) {
        this.classificacao = classificacao;
    }

    public char getClassificacao() {
        return classificacao;
    }

    @Converter(autoApply = true)
    public static class Mapeador implements AttributeConverter<Classificacao, String> {

        @Override
        public String convertToDatabaseColumn(Classificacao x) {
            return String.valueOf(x.getClassificacao());
        }

        @Override
        public Classificacao convertToEntityAttribute(String y) {
            if (y == null) return null;
            if ("P".equals(y)) return POSITIVO;
            if ("N".equals(y)) return NEGATIVO;
            throw new IllegalStateException("Valor inválido: " + y);
        }
    }
}

import javax.persistence.Convert;

// ...

    //@Enumerated(EnumType.STRING)
    @Convert(converter = Classificacao.Mapeador.class)
    @Column(name = "classificacao", length = 1)
    private Classificacao classificacao;

Note that the @Enumerated was removed from the mapping.