WebLogic Filtering ClassLoader and ClassLoader Analysis Tool Demo
- 1. WebLogic Server 11gR1 PS3 (10.3.4) DEMOFiltering ClassLoader & Classloader Analysis ToolJeffrey WestApplication Grid Product Management
- 2. AgendaOverview of WebLogic’s ClassLoadersOverview of WebLogic’s ClassLoader Analysis ToolDemo of WebLogic’s ClassLoader Analysis ToolConclusion & WebLogic Resources
- 3. WebLogic ClassLoader HierarchyTop-Down Class Loading (Default)SYSTEM ClassLoader loads:WebLogic Implementation classes
- 4. Classes on the System Classpath
- 5. PRE_CLASSPATH and EXT_PRE_CLASSPATHSYSTEMDOMAIN ClassLoader loads:Classes from <domain_dir>/lib DOMAINAPPLICATION ClassLoader loads:Java EE Shared Libraries referenced in weblogic-application.xml
- 6. Any Modules defined in the application
- 7. Libraries from Java EE 5 <library-directory> directive or /lib if none configured
- 8. Libraries from <EAR>/APP-INF/lib APPLICATIONWEB APP ClassLoader loads:Java EE Shared Libraries referenced in weblogic.xml
- 10. WEB-INF/lib
- 11. Enables Servlets and JSPs to see EJB classes
- 12. Enables redeployment of Web Apps w/o redeploying EJBsWEB APP
- 13. APPLICATIONWEB APPWebLogic Filtering ClassLoaderForce classes to be loaded from the APPLICATIONThe FilteringClassLoader mechanism allows you to specify classes that should always be loaded from the application (not the SYSTEM ClassLoader)This allows you to use alternate versions of applications, such as Xerces and Ant, than those that are packed with WebLogicEnables resources from the child of the FilteringClassLoader (an Application classloader) down to the calling classloader are returned before the ones from the system classloaderThe FilteringClassLoader is configured with a list of packages specified in weblogic-application.xml or weblogic.xml (introduced in 10.3.3) files. SYSTEMDOMAINFILTERINGClassLoader
- 14. Filtering ClassLoader ConfigurationSpecify Packages to load from APP-INF/lib & WEB-INF/libSpecify the packages that should be loaded by the Application including:Java EE Shared LibrariesEAR: /lib (preferred)EAR: APP-INF/lib WAR: WEB-INF/libOverrides the classes that are loaded with WebLogic allowing you to use libraries that may conflict with those included in WebLogic
- 15. There are two options for configuring the classloader in at the Web Application level<container-descriptor> / <prefer-application-packages><container-descriptor> / <prefer-web-inf-classes>Only one of these options can be used at a timeOracle recommends using <prefer-application-packages> to configure the FilteringClassLoader<prefer-application-packages>(Recommended)<prefer-web-inf-classes>Allows a Web Application to use its own third-party libraries from WEB-INF/lib by specifying certain packages that should always be loaded from the Web ApplicationAllows a Web application to use its own version third-party classes from WEB-INF/classes, which might also be part of WebLogic ServerWeb Filtering ClassLoader ConfigurationLoad Classes from WEB-INF
- 16. Customer ClassLoader StructureAdvanced Configuration for Reloading ClassesCustom classloader hierarchies allow better control over class visibility and reload-abilityThe ability to create custom module ClassLoaders provides a mechanism to declare alternate classloader organizations that allow the following:Reloading individual EJB modules independentlyReloading groups of modules to be reloaded togetherReversing the parent child relationship between specific Web modules and EJB modulesNamespace separation between EJB modules
- 17. AgendaOverview of WebLogic’s ClassLoadersOverview of WebLogic’s ClassLoader Analysis ToolDemo of WebLogic’s ClassLoader Analysis ToolConclusion & WebLogic Resources
- 18. WebLogic ClassLoader Analysis ToolNEW in WebLogic 11gR1 (10.3.4)Application provided libraries can collide with 3rd party libraries used by WebLogic ServerHard to diagnose class and library conflictsFiltering Classloader feature enables applications to use their own librariesCorrectly configuring it can be a challengeClassloader Analysis Tool Helps Identify and Resolve Conflicts QuicklyCAT cracks open the classloader black boxDisplays classloaders’ hierarchies and sourcesAllows you to search for a class/resource on a classloaderViews class definitions, interfacesAnalyzes classpath conflicts, generates corresponding filtering classloader configurationCATWebLogicClassLoaders
- 19. Analyze Classpath ConflictsWebLogic 10.3.4 ClassLoader Analysis ToolThe ClassLoader Analysis tool shows you where the class conflicts areThis allows you to see the conflicting libraries, where they are located and allows you to decide how to resolve itClassLoader Configuration SuggestionWebLogic 10.3.4 ClassLoader Analysis ToolThe ClassLoader Analysis tool provides the XML configuration necessary for configuring the Filtering ClassLoaderThis significantly eases the configuration required to take advantage of this advanced featureOnly available in WebLogic 10.3.4 and later
- 20. AgendaOverview of WebLogic’s ClassLoadersOverview of WebLogic’s ClassLoader Analysis ToolDemo of WebLogic’s ClassLoader Analysis ToolConclusion & WebLogic Resources
- 21. AgendaOverview of WebLogic’s ClassLoadersOverview of WebLogic’s ClassLoader Analysis ToolDemo of WebLogic’s ClassLoader Analysis ToolConclusion & WebLogic Resources
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