What is local interface in EJB?

The local interface is a standard Java interface. It does not inherit from RMI. An enterprise bean uses the local interface to expose its methods to other beans that reside within the same container.

What is the difference between local and remote interface in EJB?

Using the remote and local interfaces appropriately means that clients can access EJB components efficiently. That is, local clients use the local interface with pass-by-reference semantics, while remote clients use the remote interface with pass-by-value semantics.

What is EJB stub?

Stub is used by the client to invoke methods on the remote EJB — it is basically a proxy object that implements the remote interface. It is responsible for serializing the invocation into a byte stream and sending it to the server hosting the EJB.

What do you mean by home interface?

The home interfaces are used to specify what methods a client uses to create or retrieve an entity bean instance. The home interface must contain a create method, which the client invokes to create the bean instance. The entity bean can have zero or more create methods, each with its own defined parameters.

What is no-interface view?

A no-interface view of an enterprise bean exposes the public methods of the enterprise bean implementation class to clients. Clients using the no-interface view of an enterprise bean may invoke any public methods in the enterprise bean implementation class or any superclasses of the implementation class.

What are the different types of interfaces used in EJB?

An EJB has two client interfaces:

• Remote interface–The remote interface specifies the business methods that the clients of the object can invoke.
• Home interface–The home interface defines EJB life cycle methods, such as a method to create and retrieve a reference to the bean object.

How do I access my EJB remote?

Steps for Accessing Any EJB

1. If you are remote, download the oc4j. jar file.
2. Set up JNDI properties for the connection, if necessary.
3. Determine which InitialContextFactory you will use for the connection.
4. Retrieve an EJB using either the JNDI name or an EJB reference, which is configured in the deployment descriptor.

What is EJBObject?

The EJBObject -> An instance of a generated class that implements the remote interface defined by the bean developer. This instance wraps the bean and all client interaction is made through this object. The EJBObject does not have persistent state.

When should I opt BMP over CMP?

The bottom line is that if your beans can be deployed in any application server, and you know what you are doing with JDBC and EJB (a very big concern!), BMP should always win out over CMP in performance.

Which EJB has no remote interface?

A Message driven bean has no remote interface.

Why do computer need a user interface?

User interfaces enable users to effectively control the computer or device they are interacting with. A successful user interface should be intuitive, efficient, and user-friendly.

Can EJB components have remote and local interfaces?

Prefer Local Interfaces An EJB component can have remote and local interfaces. Clients not located in the same application server instance as the bean (remote clients) use the remote interface to access the bean.

Why do we use pass-by-reference semantics in EJB?

In general, it is more efficient to use pass-by-reference semantics when possible. Using the remote and local interfaces appropriately means that clients can access EJB components efficiently. That is, local clients use the local interface with pass-by-reference semantics, while remote clients use the remote interface with pass-by-value semantics.

Why should I use the local interface instead of remote interface?

Thus, using the remote interface entails significant overhead. If an EJB component has a local interface, then local clients in the same application server instance can use it instead of the remote interface. Using the local interface is more efficient, since it does not require argument marshalling, transportation, and un-marshalling.

Should a bean have both a remote and local interface?

If, on the other hand, the bean is to be location-independent, then you should provide both the remote and local interfaces so that remote clients use the remote interface and local clients can use the local interface for efficiency. Using Pass-By-Reference Semantics