Looking up an EJB 3.0 EJB

Using EJB 3.0, you can look up an EJB using resource injection (see "Using Annotations") or the InitialContext (see "Using Inital Context").

Using Annotations

Example 19-19 shows how to use annotations and dependency injection to access an EJB 3.0 EJB from an EJB client.

Example 19-19 Injecting an EJB 3.0 EJB in an EJB 3.0 EJB Client

@EJB AdminService bean;
 
    public void privilegedTask()
    {
        bean.adminTask();
    }

Example 19-20 shows how to use annotations and dependency injection to access an EJB 2.1 EJB from an EJB 3.0 EJB client.

Example 19-20 Injecting an EJB 2.1 EJB in an EJB 3.0 EJB Client

@EJB(
    name="ejb/shopping-cart", // optional
    beanName="cart1", // optional
    beanInterface=ShoppingCartHome.class, // optional
    description="The shopping cart for this application" //optional
)
private ShoppingCartHome myCartHome;

Using Inital Context

This section describes:

Looking Up the Remote Interface of an EJB 3.0 EJB Using ejb-ref
Looking Up the Remote Interface of an EJB 3.0 EJB Using location
Looking up the Local Interface of an EJB 3.0 EJB Using local-ref
Looking up the Local Interface of an EJB 3.0 EJB Using local-location

For more information, see "Configuring the Initial Context Factory".

Looking Up the Remote Interface of an EJB 3.0 EJB Using ejb-ref

To look up the remote interface of an EJB using an ejb-ref:

Define an ejb-ref for the EJB in the ejb-jar.xml file.
Example 19-21 ejb-jar.xml For an ejb-ref
```
<ejb-ref>
    <ejb-ref-name>ejb/Test</ejb-ref-name>
    <ejb-ref-type>Session</ejb-ref-type>
    <local>Test</local>
</ejb-ref>
```
For more information, see "Configuring an Environment Reference to a Remote EJB").
Determine whether or not a prefix is required (see "Selecting an EJB Reference").
Look up the EJB using the ejb-ref-name and the appropriate prefix (if required).
Example 19-22 Looking Up Using ejb-ref in an EJB 3.0 EJB Client Using Initial Context
```
InitialContext ic = new InitialContext();
Cart cart = (Cart)ic.lookup("java:comp/env/ejb/Test");
```
For more information, see "Configuring the Initial Context Factory".

Looking Up the Remote Interface of an EJB 3.0 EJB Using location

To look up the remote interface of an EJB using its location:

Define the entity-deployment attribute location in the orion-ejb-jar.xml file.
Example 19-23 orion-ejb-jar.xml For location
```
<entity-deployment
    name="Test"
    location="app/Test"
    ...
>
...
</entity-deployment>
```
The default value for location is the value of entity-deployment attribute name.
Determine whether or not a prefix is required (see "Selecting an EJB Reference").
Look up the EJB using the location.
Example 19-24 Looking Up Using location in an EJB 3.0 EJB Client Using Initial Context
```
InitialContext ic = new InitialContext();
Cart cart = (Cart)ic.lookup("java:comp/env/app/Test");
```
For more information, see "Configuring the Initial Context Factory".

Looking up the Local Interface of an EJB 3.0 EJB Using local-ref

To look up the remote interface of an EJB using an ejb-local-ref:

Define an ejb-local-ref for the EJB in the ejb-jar.xml file.
Example 19-25 ejb-jar.xml For an ejb-local-ref
```
<ejb-local-ref>
    <ejb-ref-name>ejb/Test</ejb-ref-name>
    <ejb-ref-type>Session</ejb-ref-type>
    <local>Test</local>
</ejb-local-ref>
```
For more information, see "Configuring an Environment Reference to a Local EJB").
Determine whether or not a prefix is required (see "Selecting an EJB Reference").
Look up the EJB using the ejb-ref-name and the appropriate prefix (if required).
Example 19-26 Looking Up Using local-ref in an EJB 3.0 EJB Client Using Initial Context
```
InitialContext ic = new InitialContext();
Cart cart = (Cart)ctx.lookup("java:comp/env/ejb/Test");
```
For more information, see "Configuring the Initial Context Factory".

Looking up the Local Interface of an EJB 3.0 EJB Using local-location

To look up the local interface of an EJB using its local-location:

Define the entity-deployment attribute local-location in the orion-ejb-jar.xml file.
Example 19-27 orion-ejb-jar.xml For local-location
```
<entity-deployment
    name="Test"
    local-location="app/Test"
    ...
>
...
</entity-deployment>
```
The default value for location is the value of entity-deployment attribute name.
Determine whether or not a prefix is required (see "Selecting an EJB Reference").
Look up the EJB using the local-location.
Example 19-28 Looking Up Using local-location in an EJB 3.0 EJB Client Using Initial Context
```
InitialContext ic = new InitialContext();
Cart cart = (Cart)ctx.lookup("java:comp/env/app/Test");
```
For more information, see "Configuring the Initial Context Factory".