Manage shared libraries

Shared libraries are files used by multiple applications. Each shared library consists of a symbolic name, a Java class path, and a native path for loading Java Native Interface (JNI) libraries. You can use shared libraries to reduce the number of duplicate library files on your system.

Overview

Using the administrative console, you can define a shared library.

You can define a shared library at the cell, node, or server level.

On a V6.1.0.11 and later multiple-server product, you also can define a shared library at the cluster level.

A separate class loader is used for shared libraries that are associated with an application server. This class loader is the parent of the application class loader, and the WebSphere Application Server extensions class loader is its parent. Shared libraries that are associated with an application are loaded by the application class loader.

Defining a library at one of the these levels does not automatically place the library into the class loader for an application server. You must associate the library to an application or server before the classes represented by the shared library are loaded into either a server-wide or application-specific class loader.

Using the administrative console, you can then associate the library with an application, module, or server to load the classes represented by the shared library in either a server-wide or application-specific class loader.

Using an installed optional package, you can associate a shared library to an application by declaring the dependent library .jar file in the MANIFEST.MF file of the application. Refer to the J2EE 1.4 specification, section 8.2 for an example.

If your deployed applications use shared library files, define shared libraries for the library files and associate the libraries with specific applications or modules or with an application server. Associating a shared library file with a server associates the file with all applications on the server. Use the administrative console Shared Libraries page to define new shared library files to the system and to remove existing library files from the system.

Procedure

• Use the administrative console to define a shared library.

  1. Create a shared library for each library file that your applications need.

  2. Associate each shared library with an application or module.

     • Associate a shared library with an application or module that uses the shared library file.

     • Associate a shared library with an application server so every application on the server can use the shared library file.

• Use an installed optional package to declare a shared library for an application.

• Remove a shared library.

  1. Click Environment > Shared Libraries in the console navigation tree to access the Shared Libraries page.

  2. Select the library to be removed.

  3. Click Delete.

  The list of shared libraries is refreshed. The library file no longer displays in the list.

Related concepts

Related tasks

Related Reference