How to deep copy a Hibernate entity while using a newly generated entity identifier

I’m using a relational DB using a single column pk with a few nested tables.

I need to add a simple archiving to my project. The archiving only happens when the application reaches a particular state, so what I was hoping to do was copy my existing hibernate object into a new instance where the new instance would be saved with a new ID while leaving the existing object intact.

I can’t seem to figure out how to copy the existing object into a new instance without manually having to set every single new instance field.

Does anybody know of a simple way of doing this?

Answer

I am also working with Hibernate and I got the same requirement you got. What I followed was to implement Cloneable. Below is a code example of how to do it.

class Person implements Cloneable {

        private String firstName;
        private String lastName;

        public Object clone() {

            Person obj = new Person();
            obj.setFirstName(this.firstName);
            obj.setLastName(this.lastName);

            return obj;
        }

        public String getFirstName() {
            return firstName;
        }

        public void setFirstName(String firstName) {
            this.firstName = firstName;
        }

        public String getLastName() {
            return lastName;
        }

        public void setLastName(String lastName) {
            this.lastName = lastName;
        }
    }

Or you could go to a reflection based solution but I won’t recommend that. Check this website for more details.