Interstage Studio User's Guide

3.3.5 Creating EJB Clients

This section describes how to create a client that invokes a session bean business method and a client that sends messages to a message-driven bean.

3.3.5.1 Creating Clients that invoke Session Beans

A special definition file is not required when creating a client that invokes a session bean. In the Java class (servlet or similar) that is used as the client, code the processing that gets the session bean business interface and the processing that uses the interface to invoke the business method.

Creating the Business Interface

The business interface can be fetched easily using the Dependency Injection.
Use @EJB annotation as shown below to get the business interface.

Example of using EJB Annotation

@EJB
private Calc calc;

Coding Example	Explanation
ejb/Calc	Specify the JNDI name associated with the session bean.
Calc	This is the business interface. (It is a local interface.)
Calc#add(int, int)	This is the business method.

Note

The Dependency Injection can be used only in Java EE components managed in Java EE containers, such as servlets, EJB, and so on. For other classes, use JNDI lookup to get objects.
For details, refer to "10.2.2 Using JNDI Lookup to Obtain Objects".

Invoking the Business Method

To invoke the business method, use the obtained business interface to invoke the method.

Example of Invoking a Business Method

int result = calc.add(100,200);

3.3.5.2 Creating Clients that send Messages to Message-driven Beans

A special definition file is not required when creating a client that sends messages to a message-driven bean. In the Java class (servlet or similar) that is used as the client, code the processing that fetches the message-driven bean JMS connection factory or similar and the processing that uses this to send messages.

The explanation below is for sending messages to a point-to-point model message-driven bean.

Fetching the JMS Connection Factory and the JMS Destination

The JMS connection factory and the JMS Destination can be fetched easily using a Dependency Injection.
Use an @Resource annotation such as the following to fetch the JMS connection factory and the JMS Destination.

Example of Using Resource Annotation

@Resource(name="jms/QueueCF001")
private QueueConnectionFactory qcf;
@Resource(name="jms/Queue")
private Queue queue;

Coding Example	Explanation
jms/QueueCF001	JMS connection factory name
jms/Queue	JMS Destination name

Note

The Dependency Injection can be used only in Java EE components managed in Java EE containers, such as servlets, EJB, and so on. For other classes, use JNDI lookup to fetch objects.
For details, refer to "10.2.2 Using JNDI Lookup to Obtain Objects".

Sending Messages

After the JMS connection factory and the JMS Destination are fetched, the message sending procedure is the same as for up to EJB 2.1. An example is below.

Example of Sending a Message

// Create connection, session, and sender
QueueConnection connection = qcf.createQueueConnection();
QueueSession session = connection.createQueueSession(false, Session.AUTO_ACKNOWLEDGE);
QueueSender sender = session.createSender(queue);
// Send a text message
TextMessage msg = session.createTestMessage();
msg.setText("Hello World!");
sender.send(msg);
// Close
connection.close();