Using Heavy Class Loaders
Besides the normal class loader, an application can also have a heavy class loader. Its purpose is to load the classes from the archives bundled into the application with highest priority, before all other resources referenced by the application.
Heavy loaders behavior is switched on.
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1. Pack your custom classes as a bundled library in the application.
It is mandatory that:
○ The application packing your custom libraries is Java EE 5 application.
○ All the custom libraries are located in the /lib folder.
○ The EAR contains application-service.xml (even if practically empty) – this is achieved by adding the SAP Application Library Container facet to your project.
2. Deploy your application or applications.
You can check that your libraries have been loaded by the heavy loader with the llr command in Telnet.

>llr com.vendorX/Hibernate-library-loader
Loader name:
[com.vendorX/Hibernate-library-loader]
Direct parent loaders:
[library:javax~persistence~api]
[library:ejb_api]
Direct child loaders:
[com.vendorX/Hibernate]
Resources:
C:\usr\sap\CE1\...\app_libraries_container\lib\jboss-archive-browsing.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\lucene-core-2.0.0.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\asm-attrs.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\antlr-2.7.6.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\commons-collections-2.1.1.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\commons-logging-1.0.4.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\javassist.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\hibernate3.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\log4j-1.2.11.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\hibernate-annotations.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\hibernate-entitymanager.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\cglib-2.1.3.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\ehcache-1.2.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\dom4j-1.6.1.jar
C:\usr\sap\CE1\...\app_libraries_container\lib\asm.jar