java.lang.IllegalArgumentException: You have provided an instance of an incorrect PK class for this find operation. - jpa

Question

I'm trying to create a URI and returns an object looking for NIF. (One custom filter)
I have tried to replicate the search by id but does not work, the truth, I'm not sure what I do. I have two classes with these functions
ClientesAbstractFacade.java
public T findNif(Object nif) {
return getEntityManager().find(entityClass, nif);
}
lientesFacadeREST.java
#GET
#Path("nif/{nif}")
#Produces({MediaType.APPLICATION_JSON})
public Clientes findNif(#PathParam("nif") String nif) {
return super.findNif(nif);
}
And here POJO
#Entity
#Table(name = "clientes")
public class Clientes implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
#Basic(optional = false)
#Column(name = "id")
private Integer id;
As you can see, I'm trying to do custom searches, something easy, and then implement a login.
But I can not even filter by nif, these return error 500
java.lang.IllegalArgumentException: You have provided an instance of an incorrect PK class for this find operation. Class expected : class java.lang.Integer, Class received : class java.lang.String.

Answer 1

The exception says it all:
IllegalArgumentException: You have provided an instance of an incorrect PK class for this find operation. Class expected : class java.lang.Integer, Class received : class java.lang.String
The getEntityManager().find(entityClass, nif) is working on the Primary Key column of your Table. This is, as the exception states, an Integer.
I guess you want to use your NamedQueries and have thus to use createNamedQuery-methods of the EntityManager.
So your find-method should look something like that:
public T findNif(String nif) {
return (T) getEntityManager().createNamedQuery("Clientes.findByNif", Clientes.class)
.setParameter("nif", nif).getSingleResult();
}