Remote Clients

A remote client of an enterprise bean has the following traits.

• It can run on a different machine and a different JVM from the enterprise bean it accesses. (It is not required to run on a different JVM.)

• It can be a web component, an application client, or another enterprise bean.

• To a remote client, the location of the enterprise bean is transparent.

• The enterprise bean must implement a business interface. That is, remote clients may not access an enterprise bean through a no-interface view.

To create an enterprise bean that allows remote access, you must either

• Decorate the business interface of the enterprise bean with the @Remote annotation:

  @Remote
  public interface InterfaceName { ... }

• Decorate the bean class with @Remote, specifying the business interface or interfaces:

  @Remote(InterfaceName.class)
  public class BeanName implements InterfaceName { ... }

The remote interface defines the business and lifecycle methods that are specific to the bean. For example, the remote interface of a bean named BankAccountBean might have business methods named deposit and credit. Figure 14–1 shows how the interface controls the client’s view of an enterprise bean.

Figure 14–1 Interfaces for an Enterprise Bean with Remote Access

Client access to an enterprise bean that implements a remote business interface is accomplished through either dependency injection or JNDI lookup.

• To obtain a reference to the remote business interface of an enterprise bean through dependency injection, use the javax.ejb.EJB annotation and specify the enterprise bean’s remote business interface name:

  @EJB
  Example example;

• To obtain a reference to a remote business interface of an enterprise bean through JNDI lookup, use the javax.naming.InitialContext interface’s lookup method:

  ExampleRemote example = (ExampleRemote)
          InitialContext.lookup("java:global/myApp/ExampleRemote");