Sun GlassFish Enterprise Server 2.1 Developer's Guide

Application-Specific Class Loading

You can specify application-specific library classes during deployment in one of the following ways:

Application libraries are included in the Application class loader. Paths to libraries can be relative or absolute. A relative path is relative to domain-dir/lib/applibs. If the path is absolute, the path must be accessible to the domain administration server (DAS). The Enterprise Server automatically synchronizes these libraries to all remote cluster instances when the cluster is restarted. However, libraries specified by absolute paths are not guaranteed to be synchronized.


Tip –

You can use application-specific class loading to specify a different XML parser than the default Enterprise Server XML parser. For details, see http://blogs.sun.com/sivakumart/entry/classloaders_in_glassfish_an_attempt.

You can also use application-specific class loading to access different versions of a library from different applications.


If multiple applications or modules refer to the same libraries, classes in those libraries are automatically shared. This can reduce the memory footprint and allow sharing of static information. However, applications or modules using application-specific libraries are not portable. Other ways to make libraries available are described in Circumventing Class Loader Isolation.

For general information about deployment, see the Sun GlassFish Enterprise Server 2.1 Application Deployment Guide.


Note –

If you see an access control error message when you try to use a library, you may need to grant permission to the library in the server.policy file. For more information, see Changing Permissions for an Application.