According to the spec , if a container managed entity bean was passivated
and it had a reference to another entity bean, then the container is
responsible for re-establishing the reference to that bean. But if the
reference was a Java object that that was not a bean, then it seems to me
that upon activation, the bean could end up with that instance variable
referencing a different object and bean developer is responsible for
re-establishing the reference to the correct java object or re-setting it to
null. Thus whenever a new instance variable is added that is non
persistent, the bean developer should remember to change the activate *and*
create method and initialize the instance variable , atleast to null. Is
this correct ?
Thanks for your input. These things are not obvious from the spec ( atleast
to me ) and I want to be sure of my understanding of the spec. :-)
Sachin.
> -----Original Message-----
> From: A mailing list for Enterprise JavaBeans development
> [mailto:[EMAIL PROTECTED]]On Behalf Of Richard Monson-Haefel
> Sent: Wednesday, March 17, 1999 8:41 AM
> To: [EMAIL PROTECTED]
> Subject: Inital values of activated beans: (was RE: ejbCreate( ) -
> initial ize instance variables
>
>
> The initial values set for fields in an Entity bean by the container with
> regard to activation, should be the default values of the
> instance: null for
> objects, zero for number primitives, and false for boolean.
>
> The specification is clear that bean developer should not define a
> constructor in the bean. I think this implies that bean developers should
> not initialize values in field declarations also, since this is
> activity is
> done during instantiation.
>
> Any initialization of values by the bean developer should be done in
> ejbCreate and ejbActivate methods.
>
>
> Richard
>
>
> -----Original Message-----
> From: Imre Kifor
> To: [EMAIL PROTECTED]
> Sent: 3/17/99 8:25 AM
> Subject: Re: ejbCreate( ) - initialize instance variables
>
> The spec states that all bean instances must be created using
> newInstance()
> on the bean's class. This means that there will be only one valid
> initial
> state per bean class in a running server (and is created through the
> bean's
> default public constructor).
>
> We keep one such "template" instance around for all deployed bean
> classes
> and before the server releases an instance back to the pool, we "wipe"
> the
> instance's state clean with the template using reflection. No
> serialization
> is required in the process and, since we operate on the Java 2 platform,
> we
> can reset private members as well.
>
> Imre Kifor
> Valto Systems
>
> -----Original Message-----
> From: Constantine Plotnikov <[EMAIL PROTECTED]>
> To: [EMAIL PROTECTED] <[EMAIL PROTECTED]>
> Date: Wednesday, March 17, 1999 8:50 AM
> Subject: Re: ejbCreate( ) - initialize instance variables
>
>
> >Hi!
> >
> >1. Do I understand it correctly? In your server, initial values for
> all
> > fields are saved for each instance and they are restored right
> before
> > creation.
> >
> >2. If yes, how do you save values?
> > a) in serialized form
> > b) just pointers to values recived as Field.get()
> > c) other, please clarify what.
> >
> >3. If no, could you please clarify semantics of restoring values
> > in your server.
> >
> >Constantine
> >
> >Imre Kifor wrote:
> >>
> >> We believe that bean instances retrieved from the instance pool
> should
> >> always be in their initial state (i.e. the state right after
> construction)
> >> regardless of the used persistence management type.
> >>
> >> This means that with Ejipt your 'country' member will be predictably
> set
> to
> >> "USA" upon entering ejbCreate, ejbFindXXX and ejbActivate. Moreover,
> since
> >> Ejipt resets all instances before returning them to the pool, you
> will
> also
> >> be assured that your possibly sensitive or very large member data is
> not
> >> held by pooled instances.
> >>
> >> Imre Kifor
> >> Valto Systems
> >>
> >> -----Original Message-----
> >> From: Sachin Aggarwal <[EMAIL PROTECTED]>
> >> To: [EMAIL PROTECTED] <[EMAIL PROTECTED]>
> >> Date: Tuesday, March 16, 1999 11:26 PM
> >> Subject: ejbCreate( ) - initialize instance variables
> >>
> >> >The spec mentions that ejbCreate( ) initializes instance variables.
> >> >
> >> >Question 1. Who's reponsibility is that in CMP beans ? The
> containers or
> >> the
> >> >bean developers?
> >> >
> >> >If the answer to above is Bean Developer, then:
> >> >Q2. If the instance variable is declared as public String county =
> "USA";
> >> >and the bean developer does not reinitialize it in ejbCreate(), then
> does
> >> >the container have the right to initialize it to unpredicatable
> values ?
> >> >
> >> >Thanks for your help.
> >> >
> >>
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> >> >
> >> >
> >>
> >>
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