EJB modules
Enterprise Java bean (EJB) modules are used to assemble one or more enterprise beans into a single deployable unit. An EJB module is stored in a standard Java archive (JAR) file.
An EJB module can be used as a standalone module, or it can be combined with other modules to create an enterprise module. An EJB module is installed and run in an enterprise bean container. An EJB project must be referenced by an enterprise module project (defined as a module in an EAR file) ) in order to be deployed successfully and run on a server.
An EJB module has the following characteristics:
- It contains one or more deployable enterprise beans.
- Optional: It might contain a deployment descriptor, stored in an Extensible Markup Language (XML) file. This file declares the contents of the module, defines the structure and external dependencies of the beans in the module, and describes how the enterprise beans are to be used at run time.
- It targets one of the following:
- IBM WebSphere® Application Server v7.0, which is already enabled with EJB 3.0 support.
- IBM WAS v6.1 with the Feature Pack for Enterprise Java Beans 3.0 installed.
An EJB module contains these elements:
- One or more deployable enterprise beans.
- A deployment descriptor, stored in an XML file. This file declares the contents of the module, defines the structure and external dependencies of the beans in the module, and describes how the beans are to be used at run time.
Note: It is not necessary to use XML deployment descriptors in EJB 3.0 modules, although XML descriptors are supported. Instead of deployment descriptors, use annotations to provide component metadata.
You can deploy an EJB module as a stand alone application, or combine it with other EJB modules or with Web modules to create a Java application. An EJB module is installed and run in an enterprise bean container.
Note: EJB modules that contain EJB 3.0 beans must be at the EJB 3.0 specification level when running on the product. To set the EJB module to support EJB 3.0 beans, you can set the EJB version in the project facet to 3.0, or you can make sure that the module does not contain an ejb-jar.xml deployment descriptor. If the module level is EJB 2.1 or earlier, no EJB 3.0 functions, including annotation scanning or resource injection, is performed at runtime.
Related concepts
Developing EJB 3.0 Applications
Differences between EJB 3.0 and EJB 2.1
Securing enterprise applications
Deploying EJB 3.0 applications
Related tasks
Related reference
Considerations for developing EJB 3.0 modules for the Feature Pack for EJB 3.0