Problems in JPA with a Collection of Dates

[Stevie Braga]

Hi!
I'm using JPA to do my O/R mapping, and I'm facing this problem: one User have a Set of quitting dates. So my mapping look like this:

@OneToMany
@JoinTable(name = "user_x_quitting_date", 
           joinColumns = @JoinColumn(name = "user"))
private Set<Date> quittingDates;

But I keep getting this message when I try to run a test:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'entityManagerFactory' defined in class path resource [com/packagename/applicationContext.xml]: Invocation of init method failed; nested exception is org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class: com.packagename.quittingDates[java.util.Date]
Caused by: org.hibernate.AnnotationException: Use of @OneToMany or @ManyToMany targeting an unmapped class: com.packagename.quittingDates[java.util.Date]

Can anyone tell me what I'm doing wrong?

Thanks

[ July 04, 2007: Message edited by: Stevie Braga ]
[ July 04, 2007: Message edited by: Stevie Braga ]

[Ali Hussain]

Note sure but it seems to be a bug in hibernate release. A possible workaround could be: private Date[] quittingDates;

Let us know if you find some other solution.

[Ali Hussain]

This would also work:

@Lob
private Set quittingDates = new HashSet<Date>();

See this bug report and the workaround

[Stevie Braga]

I found out what I was doing wrong!

The @OneToMany annotation is use for relationships between entities, and I was trying to map a simple collection, not a collection of entities.
So I used the @CollectionOfElements annotation from hibernate, and it's working allright now! So now the code look like this:

@CollectionOfElements(targetElement = java.util.Date.class)
@JoinTable(name = "user_x_qutting_date", 
           joinColumns = @JoinColumn(name = "user"))
@IndexColumn(name = "position")
@Column(name = "quitting_date")
private List<Date> quittingDates;

Thanks for the attention Ali!

[Ali Hussain]

Are you sure you want to use a hibernate annotation @CollectionOfElements in your code (I assume you want your code to be JPA compatible so you can change to any other implementation without changing the code)?

[Erik Bengtson]

JPA does not support collections of dates. it only support collection of entities...

You need to wrap your date within an Entity (argh)...

FYI, JDO supports collections of any type.