如何使用Hibernate正确映射MonetaryAmount？

Question

当我尝试将我的自定义Expenditure对象映射到MySQL中的关系模型时，我收到错误：

Initial SessionFactory creation failed.org.hibernate.MappingException: Could not determine type for: javax.money.MonetaryAmount, at table: Expenditure, for columns: [org.hibernate.mapping.Column(monetaryAmount)]

我的支出课程：

@Entity
public class Expenditure implements Comparable<Expenditure> {
    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Integer id;

    private String description;

    private MonetaryAmount monetaryAmount;

    private LocalDate date;

    private ExpenditureType type;

    @OneToOne
    private User client;
...
}

如何在此方案中执行映射？

Answer 1

你可以使用jpa'2 @Convert注释：

@Convert(converter = MonetaryAmountConverter.class)
private MonetaryAmount monetaryAmount;

然后像这样实现它：

@Converter
public class MonetaryAmountConverter implements AttributeConverter<MonetaryAmount, BigDecimal> {

    @Override
    public BigDecimal convertToDatabaseColumn(MonetaryAmount attribute) {...}

    @Override
    public MonetaryAmount convertToEntityAttribute(BigDecimal dbData) {...}
}

Answer 2

您无法直接映射MonetaryAmount。

您可以尝试将其映射到BigDecimal，然后在您的代码中执行转换，或者您可以尝试实现Hibernate自定义类型（尝试搜索@Type，或使用JPA转换（如果JPA是2.1或更高）。这个answer有一些很好的链接就此主题而言。