Using ext folder in websphere
What you need to know is that if you are using the default (Parent First) loading policy on your WebSphere server or at your application level, all the classes included in the jars inside lib / ext will definitely load the same classes into your application (for example jars in your WEB-INF / lib directory in a web application).
Inside lib / ext there are usually non-standard libraries used by WebSphere, or you can also leave your own libraries so they can be seen from any other class in WebSphere ( WARNING : This can sometimes be a source of problems).
A more flexible way to install native libraries at the WAS level is to use the WebSphere Shared Libraries...
The difference with lib / ext libraries is that you can more easily manage and install shared libraries at the server or application level, rather than dictating that every class on your server will use the lib / ext library.
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The main difference between WebSphere/AppServer/lib/ext
and shared library is that lib / ext libraries are included in all profiles and on all servers . They are also read by the server extension class loader, which is not configurable.
On the other hand, shared libraries are configured in profile specific and can be associated with a given server or specific application.
For more information, see the following pages:
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Bad idea to change / add to ext / lib content. See http://www-01.ibm.com/support/docview.wss?uid=swg27006159
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Holding global shared libraries (so there is only one global instance on the server instead of the library being packaged in every single module).
Enjoy the detailed reading material at the bottom of this technote: http://www-01.ibm.com/support/docview.wss?uid=swg21322617
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