Equals and hashcode implementation considerations

When implementing equals() and hashCode() for JPA entities, generating the primary key before object creation simplifies the implementation significantly. By requiring the id in the constructor and asserting it is non-null, you can safely base both equals() and hashCode() solely on the id field. This approach aligns with the domain-driven design principle that entities are defined by their identity, not their attributes — two objects with the same id represent the same entity regardless of other field values.