Class loader viewer settings

Class loader viewer settings

Use this page to examine the class loaders visible to a web module (.war file) or enterprise bean (.ejb file) in an installed enterprise application

This page helps you to determine which class loaders loaded files of a module and to diagnose problems with class loaders.

From the admin console, click Troubleshooting > Class loader viewer > module_name.

The module is currently running on all nodes and servers listed.

To learn more about classes used by the module and their class loaders, click a button:

Button Resulting action
Export Opens a dialog that enables us to view or save the class loader information on this page in an XML file.
Table View Display the Table view page, which provides information about class loaders visible to the module in an HTML table format for each class loader. Such information includes:

Delegation

Whether the class loader delegates a load operation to its immediate parent before searching its local classpath for a class or resource

Classpath

The local classpath, which includes the paths over which the class loader searches for classes and resources, excluding the classpaths of any parent class loaders.

Classes

The names of classes loaded by the class loader

Search Display the Search page, on which we can search class loaders for the following:

Specific strings
Specific .jar files
The names of files in a specific directory
The names of files loaded by a specific class loader

Class Loader

Display a hierarchy of class loaders that affect the loading of classes used by the web or EJB module. The Hierarchy tab displays the class loaders in a tree hierarchy. The Search Order tabs lists the class loaders in the order in which the runtime environment uses them to find and load classes.

Expand a hierarchy of class loaders to view the following:

Class loader names
Arrows that point towards the right direction indicate that it is a special class loader that does not delegate the requests to the parent.
Arrows that point upwards beside class loader names, indicating that requests can go to a parent class loader only and not go to a child class loader
The names of classes that are loaded by a class loader
The paths of property files and .jar files used by the classes

The following class loaders might be in a hierarchy:

Class loader name Description
JDK Extension Loader The JDK extensions class loader is a composite class loader that is comprised of the Java virtual machine (JVM) bootstrap class loader, the JVM extensions class loader and the JVM system class loader, which load the core SDK classes and resources as well as classes and resources visible on the JVM classpath.
WAS Extension Class Loader The WAS Extension Class Loader loads the WebSphere Application Server classes, stand-alone resource classes, custom service classes, and custom registry classes. At bootstrap, this class loader uses the ws.ext.dirs system property to determine the path used to load classes. Each directory in the ws.ext.dirs class path and every .jar file or compressed .zip file in these directories is added to the class path used by this class loader.
WAS Compound Class Loader The WAS Compound Class Loaders load classes and resources of EAR modules, web application archive (WAR) modules, and server-associated shared libraries. Under default class loader policies, an instance of a WAS Compound Class Loader exists for each running EAR and WAR module and for each class loader defined in the server configuration.

Click on Classes to view a list of classes loaded by a class loader.

The class loader viewer service must be enabled to view the list of classes.

Related:

Class loaders
Troubleshoot class loaders
Class loading
Enterprise application topology
Search settings
Web module deployment settings
EJB module settings

Class loader name	Description
JDK Extension Loader	The JDK extensions class loader is a composite class loader that is comprised of the Java virtual machine (JVM) bootstrap class loader, the JVM extensions class loader and the JVM system class loader, which load the core SDK classes and resources as well as classes and resources visible on the JVM classpath.
WAS Extension Class Loader	The WAS Extension Class Loader loads the WebSphere Application Server classes, stand-alone resource classes, custom service classes, and custom registry classes. At bootstrap, this class loader uses the ws.ext.dirs system property to determine the path used to load classes. Each directory in the ws.ext.dirs class path and every .jar file or compressed .zip file in these directories is added to the class path used by this class loader.
WAS Compound Class Loader	The WAS Compound Class Loaders load classes and resources of EAR modules, web application archive (WAR) modules, and server-associated shared libraries. Under default class loader policies, an instance of a WAS Compound Class Loader exists for each running EAR and WAR module and for each class loader defined in the server configuration.