Question about perfomance in persistence of objects

[kodaky]

Hello,

Supose we have an EntityBean called Person.java

Person.java

private Long id;
private String name;
private Country country;

A Second Entity obiously is Country :)

Country.java

private Long id;
private String name;

And finally we have a method called savePerson which uses EJB 3.0 API internally, so


public savePerson(String name, long countryId) {
...
}

MI QUESTION:

We have only countryId, but not the entire object Country, so
is necesary retrieve first the Country object from database using entitymanager?

is posible avoid this foo step and use a proxy or what ever you like?

in hibernate is posible using load() i think, but i like avoid use hibernate api explicity (in my source code)

thanks in advance

kodaky

[chochis]

You dont have to retrieve the object from the database.

Pretty simple:

create a Country object and insert the pk:
Country country = new Country();
country.setId(2);

Then create the person object and insert the contry object:
Person person = Person();
person.setCountry(country);

....
Then
em.persist(person);


About the load method, with the EntityManager you have to use find
find retrieves the class of the object and the PK;

Regards