「在關係屬性」中使用非實體[類java.lang.Double]作爲目標實體，我該怎麼做？

Question

我不能運行我的項目，因爲我得到這個錯誤：

Exception Description: Predeployment of PersistenceUnit [RekeningAdministratiePU] failed. 
Internal Exception: Exception [EclipseLink-7250] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.ValidationException 
Exception Description: [class domain.Regio] uses a non-entity [class java.lang.Double] as target entity in the relationship attribute [field wegCategoriePrijzen]. 
javax.persistence.PersistenceException: Exception [EclipseLink-28018] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.EntityManagerSetupException 
Exception Description: Predeployment of PersistenceUnit [RekeningAdministratiePU] failed. 
Internal Exception: Exception [EclipseLink-7250] (Eclipse Persistence Services - 2.3.2.v20111125-r10461): org.eclipse.persistence.exceptions.ValidationException 
Exception Description: [class domain.Regio] uses a non-entity [class java.lang.Double] as target entity in the relationship attribute [field wegCategoriePrijzen]. 

我的實體類看起來像這樣

@Id 
@GeneratedValue(strategy= GenerationType.IDENTITY) 
private Long id; 
private String naam; 
@OneToMany(cascade= { CascadeType.PERSIST,CascadeType.MERGE,CascadeType.REMOVE}) 
private Collection<Locatie> locaties; 
@OneToMany(cascade= { CascadeType.PERSIST,CascadeType.MERGE,CascadeType.REMOVE}) 
private Collection<Double> autoCategorieMutaties; 
@OneToMany(cascade= { CascadeType.PERSIST,CascadeType.MERGE,CascadeType.REMOVE}) 
private Collection<Double> wegCategoriePrijzen; 
private Double binnenrijTarief; 

我在做什麼錯在這裏？

Answer 1

@OneToMany映射的目標必須是有效的JPA實體。在你的情況下，Double類肯定不是一個實體類，因此是錯誤信息。如果您只是想存儲值的集合，請考慮使用@ElementCollection。

@ElementCollection 
private Collection<Double> wegCategoriePrijzen;