It is just an way to add hooks at different times. As you might have something available later that isn't available now.
However, now with EJB3 and AOP you can basically do the same thing without having all these interface methods like ejbPostCreate to get hooks in there.
ejbPostCreate() is called after the bean has been written to the database and the bean data has been assigned to an EJB object, so when the bean is available.
It is between ejbCreate and ejbPostCreate that the bean's proxy EJBObjectis created.
In an CMP Entity EJB, this method is normally used to manage the beans' container-managed relationship fields.
If you can imagine one to many relationship like One Customer can place multiple Orders (1..*)then you can understand that record in customer is a must to have a record(s) in order table right?
In ejbCreate() you(BMP....say container in case of CMP) can insert a row in Customer if this is successful then ejbPostCreate() will be called (where you cam do a data insertion in Order table)ensuring data integrity.
Obviously this is one of the use....One important thing to remember is Primary Key is avaialble in ejbPostCreate() & not in ejbCreate()method I hope this helps
Shrinivas
Reid M. Pinchback
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Joined: Jan 25, 2002
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Another difference, as you start mucking around with performance tuning options in a container, is that you'll find the database activities that correspond to ejbCreate and ejbPostCreate will shift around. Sometimes you can improve performance sometimes by delaying commits until after the post-create, but typically at a cost of a simple create exception instead of a duplicate key exception when you try to insert an already-used PK. [ March 13, 2006: Message edited by: Reid M. Pinchback ]
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