J2EE Libraries

The J2EE library feature in WebLogic Server 9.0 provides an easy way to share one or more types of J2EE modules among multiple Enterprise Applications.

A J2EE library is a standalone EJB or Web Application module, multiple EJB or Web Application modules packaged in an Enterprise Application (EAR), or a single plain JAR file that is registered with the J2EE application container upon deployment. After the library has been registered, you can deploy Enterprise Applications that reference the library. Each referencing application receives a reference to the required library module(s) on deployment, and can use those modules as if they were packaged as part of the referencing application itself. The shared library classes are added to the classpath of the referencing application, and the referencing application's deployment descriptors are merged (in memory) with those of the J2EE library modules

After you install a J2EE library, its name is always followed by a version of the form (Specification@Implementation), where Specification identifies the version number of the specification (for example, the J2EE specification version) to which a library or package conforms and Implementation Identifies the version number of the actual code implementation for the library or package. This versioning of J2EE libraries enables referencing applications to specify a required minimum version of the library to use, or an exact, required version.

Although not required, BEA recommends that you package and deploy J2EE libraries as part of an Enterprise application for both production and development purposes.

The following links provide information about the tasks you can perform for J2EE libraries using the Administration Console:

For detailed information about creating J2EE libraries, see Creating Shared J2EE Libraries and Optional Packages

For detailed information about deploying J2EE libraries, see Deploying Applications to WebLogic Server.