Session and Message Bean will have only ejbCreate() method and no ejbPostCreate() method. Entity bean will have both ejbCreate() and ejbPostCreate() methods.

The ejbPostCreate method returns void, and it has the same input parameters as the ejbCreate method. If we want to set a relationship field to initialize the bean instance, we should do so in the ejbPostCreate method. we cannot set a relationship field in the ejbCreate method.

The ejbPostCreate() allows the bean to do any post-create processing before it begins serving client requests. For every ejbCreate() there must be a matching (matching arguments) ejbPostCreate() method.

Hellow this is manojkumar,
I am writing simple answer for this,
Session and Message Bean will have only ejbCreate() method and no ejbPostCreate() method.

ejbpostCreate () differs from ejbCreate

Hellow this is d.pradeep
I am writing answer
Session and Message Bean will have only ejbCreate() method and no ejbPostCreate() method.

When client makes a request with homestub.create()
-->container picks one intance from the pool.
-->on that instance container calls ejbCreate() as a result insert operation takes place in the database and the instance is given with primarykey associated since the return type of ejbCreate() is primary key

-->on that container calls ejbPostCreate(),as a result,we can perforam post operation over here.....

.................Follows.............
Think hard so u can work Hard

ejbCreate :- Before Ready state all object are created. (ex :- Session Bean)
ejbPostCreate :- some object are created for initialised there state and rest object are created late (ex :- Entity Bean)

There is only ejbcreate() Method no ejbpostcreate method

session and message bean has only ejbcreate() method where as entity bean only has both ejbpostcreate() method

ejbcreate() method is only applicable to session bean... its a volatile storage whereas ejbpostcreate() method is used in entitybean as operation are taken to the updations of the database...