Class loaders are part of the Java™ virtual
machine (JVM) code and are responsible for finding and loading class
files. Class loaders enable applications that are deployed on servers
to access repositories of available classes and resources. Application
developers and deployers must consider the location of class and resource
files, and the class loaders used to access those files, to make the
files available to deployed applications. Class loaders affect the
packaging of applications and the runtime behavior of packaged applications
of deployed applications.
Before you begin
This topic describes how to configure class loaders for application files or modules that
are installed on an application server.To better understand class loaders in WebSphere® Application Server, read Class loaders.
About this task
Configure class loaders for application files or modules
that are installed on an application server using the administrative
console. You configure class loaders to ensure that deployed application
files and modules can access the classes and resources that they need
to run successfully.
Procedure
- If an installed application module uses a resource, create
a resource provider that specifies the directory name of the resource
drivers.
Do not specify the resource Java archive (JAR)
file names. All JAR files in the specified directory are added into
the class path of the WebSphere Application Server extensions
class loader. If a resource driver requires a native library (.dll
or .so
file),
specify the name of the directory that contains the library in the
native path of the resource configuration.
- Specify class-loader
values for an application server.
- Specify class-loader
values for an installed enterprise application.
- Specify the class-loader
mode for an installed web module.
- If your deployed application uses shared library files,
associate the shared library files with your application.
Use
a library reference to associate a shared library file with your application.
- If you have not done so already, define shared libraries
for library files that your applications need.
- Define a library reference for each shared library that
your application uses.
What to do next
After configuring class loaders, ensure that your application
performs as desired. To diagnose and fix problems with class loaders,
refer to Troubleshooting class loaders.