Returning a remote interface as a polymorphic form of its superinterface.

Question

Hi all
I have a remote interface 'remoteinterface1'
of a statless session enterprise java bean extending an interface 'BusinessInterface' that has some business methods.
Can a business method 'getObj()' of the bean return a polymorphic form of the above remote interface as 'BusinessInterface' i.e.
public BusinessInterface getObj()
//some conditional check is done here; if true
return remoteinterface1;
Does doing as above violate any EJB specifications. If so what could be the alternative.
Any input at the earliest is highly appreciated.
Thanks.

Answer 1

Hello,
Hi
Thanks for the quick reply.
I guess I might be asking the same question but just
wanted to confirm again by expressing one more doubt:
If the remote interface is casted to Business
Interface;
Later when I check if the business interface is an
instanceof the remoteinterface, will it be actual
remote interface i.e. since we are casting to
business interface(a simple interface and thus not an
RMI aware object), would the remote interface loose
any RMI features and thus violate EJB
specifications.You don't have to worry at all if you access a remote object (in an RMI or EJB context) through a particular interface. You just have to make sure that the interface follows the RMI rules.
This could be very useful if you want to create a number of different "views" for a remote object.
Consider for example the following:
class SomeRemoteObject implements A, B, ... {
   public void doSomething1() throws RemoteException {
   public void doSomething2() throws RemoteException {
interface A {
   public void doSomething1() throws RemoteException;
interface B {
   public void doSomething2() throws RemoteException;
interface RemoteInterfaceOfSomeRemoteObject extends A, B, ... {
}Interfaces A and B follow the RMI regulations. In this case you could access the remote object through A which disables access to doSomething2() which in turn is only accessible through B. Ofcourse the remote interface should contain the methods that you want to access remote for example by extending A and B.
public A getAnAObject() {
A anAObject = getAnAObject();
anAObject.doSomething1();
System.out.println(anAObject instanceof RemoteInterfaceOfSomeRemoteObject); // true
System.out.println(anAObject instanceof B); // true
System.out.println(anAObject instanceof java.rmi.Remote); // trueThere are indeed subtle differences in setting up the remote system (EJB or plain RMI) but the same principles always apply.
Hope it helps.
>
Thanks in advance.