Cascade persist error with JPA and EclipseLink on ManyToOne relationship

问题

Using JPA with EclipseLink I have 2 classes: User and Address.

Simplifying, in the same transaction I creates a new user, a new address and add that address to the user knowing that each user can have many addresses:

User = new User();
Address address= new Address();
user.addAddress(address);

This is the mapping in User class:

@OneToMany(mappedBy = "idUser")
private Set<Address> addresses;

This is the mapping in Address class:

@ManyToOne(cascade = { javax.persistence.CascadeType.REFRESH, javax.persistence.CascadeType.MERGE })
@JoinColumn(name = "id_user", referencedColumnName = "id", nullable = false)
private User user;

I am using a Spring Data JPA Custom Repository where I inject the entitymanager and is called from a service:

public void saveUser(TUsuario user) 
{
    em.persist(user);
}

After, I persist the Address

address.setDay(1);
address.setMonth(2);
address.setYear(3);
address.setUser(user);

public void saveUserAddress(Address address) 
{
    em.persist(address);
}

And finally, when the service method has finished, the transaction is made.

When I try to commit the thansaction an error raises:

'A new object was found through a relationship that was not marked cascade PERSIST'

If I mark the user addresses list as cascade PERSIST, then eclipselink tries to save the user twice (I think one when I persist the user and second when the user address is persisted).

How can I do it to eclipselink not to persist it, but detect it as an existing object?

PS: I tried to use merge instead of persist and didn't work.

回答1:

One error is:

@OneToMany(mappedBy = "user")//you have idUser

Then add Try the following:

User user = new User();
Address address = new Address();

address.setUser(User);
user.addAddress(address);

em.persist(user);//you can delete this, if you add PERSIST (address.user field) to the @ManyToOne(cascade = { javax.persistence.CascadeType.REFRESH, javax.persistence.CascadeType.MERGE })
em.persist(address);

来源：https://stackoverflow.com/questions/20092198/cascade-persist-error-with-jpa-and-eclipselink-on-manytoone-relationship

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java

Spring

jpa

eclipselink