Should embeddable jpa class implement equals and hashCode?

问题

Let's say I have the following scenario:

@Entity
public class Person {
    @Id
    private Long id; //Surrogate key

    @Embedded
    private Name name; //Natural key

    public int hashCode() {
        ... //based on natural key Name
    }
    public boolean equals(Object obj) {
        ... //based on natural key Name
    }
}

@Embeddable
public class Name {
    private String firstName;
    private String middleName;
    private String lastName;

    //Should I implement equals/hashCode baseed on the three fields?
}

Should Name class implement equals and hashCode on Name class in order that Person equals work properly?.

For an Embeddable object that will be used as an EmbeddedId is a must. But in this example I'm using surrogate key.

回答1:

I don't believe JPA ever requires you to implement equals and hashcode. Hibernate used to, but a recent review of the docs shows that this is no longer a requirement.

But of course it's always a good idea to implement hashcode and equals.

来源：https://stackoverflow.com/questions/4762573/should-embeddable-jpa-class-implement-equals-and-hashcode