The J2EE Connector Architecture (JCA) provides a Java technology solution to the problem of connectivity between the many application containers and today's enterprise information systems (EIS). In the 1.5 release of the JCA specification, the architecture defines an inbound communication model, whereby the EIS initiates all communication to an EJB application. The mechanism allows the inbound resource adapters to invoke Enterprise Java Beans (EJB).

Overview

This document will describe how to deploy an EJB application, so that it can receive inbound events from a JCA Adapter. It will first describe the key parts of the Resource Adapter that pertain to the inbound communication model, as well as the Geronimo-specific plans that will deploy the Resource Adapter stand-alone. It will then describe the
Enterprise Application that will be executed by the EIS, via the inbound communication mechanism.

Resource Adapter

The code described in this section are classes that will be deployed as part of a resource adapter. For the most part, there is nothing Geronimo-specific about these files. However, the end of this section will discuss how to deploy the resource adapter into a Geronimo container.

Inbound resource adapters use implementations of the interface javax.resource.spi.ActivationSpec. The interface itself has no methods, but the class implementing the interface

must be a JavaBean, providing both getter and setter methods to the bean's fields
must be serializable

According the the API documentation, "the ActivationSpec implementation will hold the activation configuration information for a message endpoint". The message endpoint, in this case, will be a Message-Driven Bean (MDB) in our enterprise application. Our ActivationSpec implementation is the class com.sample.connector.EventActivationSpec.

OrderRecvMDB.java

/*
 * EventActivationSpec.java
 */

package com.sample.connector;

import java.io.Serializable;
import javax.resource.spi.ActivationSpec;
import javax.resource.spi.InvalidPropertyException;
import javax.resource.spi.ResourceAdapter;

/**
 * Implementation of the <code>ActivationSpec</code> interface, which allows EIS Events
 * to be exposed to message-drive beans.  This <code>ActivationSpec</code> is used to
 * support inbound connection from our EIS to a message-driven bean.  This will open
 * an EIS connection and use its event mechanism provided by the EIS-specific connection
 * class.  The connection to the EIS will be held open while the application containing
 * the message-driven bean is available.
 *
 * @author Ed Hillmann
 */
public class EventActivationSpec implements ActivationSpec, Serializable  {

    private ResourceAdapter resourceAdapter;     private String serverName;
    private Integer portNumber;
    private String userName;
    private String password;
    private String eventPatterns;//A comma-delimeted string of patterns

    /**
     * Creates a new instance of the EventActivationSpec class.
     */
    public EventActivationSpec() {
    }

    /**
     * No validation is performed
     */
    public void validate() throws InvalidPropertyException {
    }

    //javadoc inherited
    public ResourceAdapter getResourceAdapter() {
        return resourceAdapter;
    }

    //javadoc inherited
    public void setResourceAdapter(ResourceAdapter resourceAdapter) {
        this.resourceAdapter = resourceAdapter;
    }     /**
     * Getter method for the ServerName attribute.  This allows the server name
     * to be defined against a Connection pool
     *
     * @return a <code>String</code> containing the server name value
     */
    public String getServerName() {
        return serverName;
    }

    /**
     * Setter method for the ServerName attribute.  This allows the server name to be
     * defined against a connection pool/.
     *
     * @param serverName the <code>String</code> that will be defined against this attribute
     */
    public void setServerName(String serverName) {
        this.serverName = serverName;
    }

    /**
     * Getter method for the PortNumber attribute.  This allows the port number
     * to be defined against a Connection pool
     *
     * @return a <code>Integer</code> containing the server port value
     */
    public Integer getPortNumber() {
        return portNumber;
    }     /**
     * Setter method for the PortNumber attribute.  This allows the server port to be
     * defined against a connection pool/.
     *
     * @param portNumber the <code>Integer</code> that will be defined against this attribute
     */
    public void setPortNumber(Integer portNumber) {
        this.portNumber = portNumber;
    }

    /**
     * Getter method for the UserName attribute.  This allows the user name
     * to be defined against a Connection pool
     *
     * @return a <code>String</code> containing the user name value
     */
    public String getUserName() {
        return userName;
    }

    /**
     * Setter method for the UserName attribute.  This allows the user name to be
     * defined against a connection pool/.
     *
     * @param userName the <code>String</code> that will be defined against this attribute
     */
    public void setUserName(String userName) {
        this.userName = userName;
    }
     /**
     * Getter method for the Password attribute.  This allows the password
     * to be defined against a Connection pool
     *
     * @return a <code>String</code> containing the password value
     */
    public String getPassword() {
        return password;
    }

    /**
     * Setter method for the Password attribute.  This allows the password to be
     * defined against a connection pool/.
     *
     * @param password the <code>String</code> that will be defined against this attribute
     */
    public void setPassword(String password) {
        this.password = password;
    }

    /**
     * Returns the event patterns that will be used when subscribing to Events.  This string can contain
     * comma-delimited value, in order to subscribe to multiple Events.
     *
     * @return a <code>String</code> containing the event patterns that will be subscribed
     */
    public String getEventPatterns() {
        return eventPatterns;
    }

    /**
     * Defines the event patterns that will be subscribed to by the message-driven beans.  The value can
     * contain comma-delimited patterns, such that multiple events can be subscribed to in the single bean.
     *
     * @param eventPatterns a <code>String</code> containing the single pattern or comma-delimited patterns
     */
    public void setEventPatterns(String eventPatterns) {
        this.eventPatterns = eventPatterns;
    }
}

Once an ActivationSpec has been implemented, the Resource Adapter's endpointActivation method can be updated.

Child pages

Inbound JCA example

Overview

Resource Adapter