Circumventing Class Loader Isolation

Since each module class loader universe is isolated, a module cannot load classes from another module. This prevents two similarly named classes in different modules from interfering with each other.

To circumvent this limitation for libraries, utility classes, or individually deployed modules, you can include the relevant path to the required classes. See Using the Common Class Loader.

Using the Common Class Loader

To use the Common class loader, copy the JAR files into the domain-dir/lib or as-install/lib directory or copy the .class files into the domain-dir/lib/classes directory, then restart the server.

Using the Common class loader makes a module accessible to all modules deployed on servers that share the same configuration.

For example, using the Common class loader is the recommended way of adding JDBC drivers to the Enterprise Server. For a list of the JDBC drivers currently supported by the Enterprise Server, see the Sun GlassFish Enterprise Server v3 Prelude Release Notes. For configurations of supported and other drivers, see Configuration Specifics for JDBC Drivers in Sun GlassFish Enterprise Server v3 Prelude Administration Guide.

To activate custom login modules and realms, place the JAR files in the domain-dir/lib directory or the class files in the domain-dir/lib/classes directory, then restart the server.