I looked in the list, but these restrictions seemed to apply to the EJB Bean
itself. I understand the container-managed instance pooling imposes this
restriction somehow, although I dont understand exactly why.
In particular, I'm wondering if static data can be moved into a utility
class which is created by the EJB bean code, and therefore get around the
static restriction.
Purpose: cache object handle JNDI lookups on bean home interfaces,
transaction mgr, etc.
Since I know these will never change, I'd like to find it once and
hold onto it.
I have a number of EJBs which will need to call each other.
Rather than
looking up the home interface via JNDI each time I need to call
another bean,
I'd like to cache it.
Something like:
class JNDICache {
private static Context initialContext_;
private static UserTransaction userTransaction_;
static public Context getInitialContext( ) {
if ( initialContext_ == null )
{
Context initialContext= null;
Properties env = System.getProperties();
env.put("java.naming.factory.initial",
"com.sun.jndi.rmi.registry.RegistryContextFactory");
try {
initialContext = new InitialContext(env);
} catch (Exception e) {
System.exit(2);
}
initialContext_= initialContext;
}
return initialContext_;
}
public UserTransaction getUserTransaction( ) {
if ( userTransaction_ == null )
{
UserTransaction utx= null;
try {
Context initialContext = getInitialContext();
utx =
(UserTransaction)initialContext.lookup("javax.transaction.UserTransaction");
} catch (Exception e) {
System.exit(2);
}
userTransaction_= utx;
}
return userTransaction_;
}
public EJBHome getEJBHome( String beanName ) {
// code to return handle to EJBHome for a given name
// via caching, using JNDI only for first call.
}
}
CODE IN EJB:
-----------
JNDICache jc= new JNDICache();
EJBHome eh= jc.getEJBHome( "BankAccount" ); // nonstatic method, static
data
EJBObject eo= eh.findByPrimaryKey( ... );
-OR-
EJBHome eh= JNDICache.getEJBHome( "BankAccount" ); // static method,
static data
EJBObject eo= eh.findByPrimaryKey( ... );
Thanks
-Steve Roth, [EMAIL PROTECTED]
> -----Original Message-----
> From: A mailing list for Enterprise JavaBeans development
> [mailto:[EMAIL PROTECTED]]On Behalf Of Rickard �berg
> Sent: Tuesday, October 26, 1999 9:52 AM
> To: [EMAIL PROTECTED]
> Subject: Re: EJB Restrictions-- threads, io
>
>
> Hey
>
> Steve Roth wrote:
> > I forgot to mention the most important restriction I've seen-- no static
> > methods/data members
> >
> > Can U have static methods/data members?
>
> No. This is strictly fobidden, for good reasons. See archive for
> details: http://archives.java.sun.com/archives/ejb-interest.html
>
> /Rickard
>
> --
> Rickard �berg
>
> @home: +46 13 177937
> Email: [EMAIL PROTECTED]
> Homepage: http://www-und.ida.liu.se/~ricob684
>
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>
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