Creating Message Driven Beans
Overview
A Message Driven Bean (MDB) is a stateless component invoked by the container as a result of the arrival of a JMS message. MDB does not have a Home or a component interface, and is an instance of a MDB class. MDB instance is created by the container to handle processing of messages, for which the bean is a consumer; the container controls its lifetime.
This document describes how to use Bean Wizard and create MDBs under a EJB 2.0 module.
Defining Message Driven Beans
Select Tools > Bean Wizard and define bean properties in the panel.
Table 1:
|
Attribute
|
Description
|
|
Module Name
|
Choose an EJB module from the dropdown. The bean when created is placed the chosen module
|
|
Bean Type
|
Define the type of bean to be created. Select bean type as Message Driven Bean from the dropdown
|
|
Transaction Type
|
Declare transaction as managed by the enterprise bean or container. Select transaction type as Container Managed or Bean Managed
|
|
Bean Class Name
|
Enter name of MDB class; if the bean is included under a package, the complete Java class name including the package name, should be entered
|
|
Adv
|
Click Adv to open the Advanced panel; enter custom interfaces implemented and custom classes extended by the bean class. Click OK to return to Bean Definition panel
|
|
EJB Name
|
Enter the logical name assigned to each bean in the ejb-jar here. This name is automatically added when the developer adds the bean class name. The name can be modified
|
|
Desc
|
Click Desc and enter the description of the EJB Name in the text box. This field is optional
|
Click Next to open the Define Message Driven Beans panel.
Defining Message Driven Beans
Provide the following details in Define Message Driven Beans panel:
Table 2:
|
Attribute
|
Description
|
|
Destination Type
|
Select destination type to which the MDB should be assigned. Destination type can be selected as Queue or Topic. Avoid associating more than one MDB with one JMS Queue
|
|
Destination Name
|
Enter name of the destination
|
|
Connection Factory
|
Select from the available Resource Manager Connection Factories in the container. Connection Factories are special entries in the enterprise bean environment and are used to create connections to the Resource Manager
|
|
Subscription Type
|
For destination type, Topic, this field is enabled. Select as durable or non-durable
|
|
Acknowledgement Mode
|
For transaction type, Bean Managed, this option is enabled. Container managed transactions handle message acknowledgement; these are used for a message received. Acknowledgement mode can be auto-acknowledge or dups-ok-acknowledge
|
Click Finish to create the MDB and the XML file under specified EJB 2.0 module.
