You can associate one or more shared libraries with an application
using an installed optional package that declares the shared libraries in
the application's manifest file. Classes represented by the shared libraries
are then loaded in the application's class loader, making the classes available
to the application.
About this task
Installed optional packages expand the existing shared library capabilities
of an application server. Prior to Version 6, an administrator was required
to associate a shared library to an application or server. Installed optional
packages enable an administrator to declare a dependency in an application's
manifest file to a shared library, with installed optional package elements
listed in the manifest file, and automatically associate the application to
the shared library. During application installation, the shared library
.jar file
is added to the class path of the application class loader.
If you use
an installed optional package to associate a shared library with an application,
do not associate the same shared library with an application class loader or a server class loader using the administrative console.
Procedure
- Assemble the library file, including the manifest information that
identifies it as an extension. Two sample manifest files follow.
The first sample manifest file has application app1.ear refer to
a single shared library file util.jar:
app1.ear:
META-INF/application.xml
ejb1.jar:
META-INF/MANIFEST.MF:
Extension-List: util
util-Extension-Name: com/example/util
util-Specification-Version: 1.4
META-INF/ejb-jar.xml
util.jar:
META-INF/MANIFEST.MF:
Extension-Name: com/example/util
Specification-Title: example.com's util package
Specification-Version: 1.4
Specification-Vendor: example.com
Implementation-Version: build96
The second sample manifest file has application app1.ear refer
to multiple shared library .jar files:app1.ear:
META-INF/application.xml
ejb1.jar:
META-INF/MANIFEST.MF:
Extension-List: util1 util2 util3
Util1-Extension-Name: com/example/util1
Util1-Specification-Version: 1.4
Util2-Extension-Name: com/example/util2
Util2-Specification-Version: 1.4
Util3-Extension-Name: com/example/util3
Util3-Specification-Version: 1.4
META-INF/ejb-jar.xml
util1.jar:
META-INF/MANIFEST.MF:
Extension-Name: com/example/util1
Specification-Title: example.com's util package
Specification-Version: 1.4
Specification-Vendor: example.com
Implementation-Version: build96
util2.jar:
META-INF/MANIFEST.MF:
Extension-Name: com/example/util2
Specification-Title: example.com's util package
Specification-Version: 1.4
Specification-Vendor: example.com
Implementation-Version: build96
util3.jar:
META-INF/MANIFEST.MF:
Extension-Name: com/example/util3
Specification-Title: example.com's util package
Specification-Version: 1.4
Specification-Vendor: example.com
Implementation-Version: build96
- Create a shared
library that represents the library file assembled in step 1.
This installs the library file as a WebSphere Application Server shared
library.
- Copy the shared library .jar file
to the cluster members.
- Assemble the application, declaring in the application manifest
file dependencies to the library files named the manifest created for step
1.
See Assemble
the application for more information.
- Install the application on the server or
cluster.
See Install the application for more information.
Results
During application installation, the shared library .jar files
are added to the class path of the application class loader.