DI, JNDI question

[Prasad Shindikar]

Imagine that you have a business interface by name 'Template'. Which of the following ways can be used by the Client Application to acquire a reference to the business interface (assuming that this interface is bound in the JNDI Context)?

1. 


      @Resource
      SessionContext context;
      Template template = (Template)context.lookup("template");
2. 

      @EJB
      Template template;
3. 


      Template template = null;
      InitialContext context = new InitialContext();
      template = (Template)Context.lookup("java:comp/ejb/template");
4. All the above. 

Correct Answer: 4. I agree with 1 and 2.

In answer option 3, should'nt the context look up be something like

template = (Template)Context.lookup("java:comp/env/ejb/template");

[Ralph Jaus]

I agree. But don't worry, it's unlikely that such mistakes occur in the exam (unless the oracle guys turn it upside down ).

[Tomas Klubal]

Hm. If you change option 3. to use

template = (Template)Context.lookup("java:comp/env/ejb/template");

then options 1. and 2. are no longer correct unless you change them as well.

Option 1.

...
Template template = (Template)context.lookup("ejb/template");

Option 2.

@EJB(name="ejb/template")
Template template;

[Siva Masilamani]

I think it depends on what kind of client you are using.

J2EE component clients or stand-alone client.

If you are using J2EE component clients(Servlet,EJBs,APPlication-client) then all of the above is true but if you are using stand-alone client,none of them is true.

You have to use traditional JNDI look up...

Correct me if i am wrong....

[Tomas Klubal]

The last option 3. is correct even for stand alone client. You can use no arg constructor for initial context if you supply jndi.properties and there is no need to narrow if what you retieve is a business interface.

[Siva Masilamani]

Yes. You are correct.

Sorry i saw this line "java:comp/ejb/template" as "java:comp/env/ejb/template"