I have the following method that returns a Person
object by Id:
private Person getPersonById(String client) {
Person output = null;
EntityManager entityManager = null;
try {
entityManager = entityManagement.createEntityManager(client);
output = entityManager.find(Person.class, id);
} catch (Exception e) {
// handle
} finally {
entityManagement.closeEntityManager(client, entityManager);
}
return output;
}
Is there a way I can make this method more generic so that I can pass in other object types, e.g.
Place
, Cost
as well? Note that these do not inherit the same super class.
E.g. should I pass e.g. Person.class
as a method parameter etc?
If you want to pass in a class object and make your method generic, you could do this:
private <E> E getObjectById(String client, Class<E> cls) {
E output = null;
EntityManager entityManager = null;
try {
entityManager = entityManagement.createEntityManager(client);
output = entityManager.find(cls, id);
} catch (Exception e) {
// handle
} finally {
entityManagement.closeEntityManager(client, entityManager);
}
return output;
}
If you pass Person.class
as the cls
argument, it would be equivalent to your original code.
That's supposing that entityManager.find
will accept any class and attempt to return an instance of that class.
If entityManager.find
has some restriction on the characteristics of the class it accepts, you would need to specify them in your generic type parameter <E>
.