New2EJB: Why do we write default ejbCreate() ?

Hi Java Gurus,
I have 3 related questions. These may be a very trivial but I am new :-)
1. Why do we need a default constructors in JavaBeans?
2. Why do we need ejbCreate() with no parametres in Enterprise JavaBeans?
3. What do I need to do to if I need to pass parameters to perform initializations for both JavaBeans and Enterprise JavaBeans?
Thanks in advance.
sledge_hammer

I'll add to that...
The first question, i am sorry that i dont know
exactly. If you are creating a java bean (not ejb),
is the default constructor mandatory?No, it is not necessary to have a default constructor (i.e. no-arg constructor) for a Java bean. If you don't define one, the compiler will creaste it. But if you define anything other than the no-arg constructor, the default constructor would not be present.
2, yes, you should provide an ejbCreate(int x) and an
ejbPostCreate(int x) in your EJB class. The first
method returns the primary key object while the
second returns null. The ejbCreate() is not
required.In case of an entity bean, it is mostly required to have an ejbCreate(some param) method with some arg. There is no restriction that the no-arg version should be defined too.

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