How to implement hashCode and equals method

Question

How should I implement hashCode() and equals() for the following class in Java?

class Emp 
{
  int empid ; // unique across all the         


        

Answer 1

If code is unique (i.e. your business key), it's best to only use the code for equals and hashCode - it's good practice to seperate business key (code) from object id (id).

Here's a nice read: Hibernate Documentation: Equals and HashCode (valid not only for Hibernate itself)