jar files imported through variable method in NWDS not working

Dear All,

My purpose is to create an adapter module to read an Excel File. The module adapter is based on the following jar files apart from the basic packages

1. EJB jar files - aii_adapter_xi_svc.jar, aii_af_cci.jar etc

2. Module jar files - com.sap.aii.af.cpa.svc.api.jar, com.sap.aii.af.lib.mod.jar etc

3. Excel jar files - poi-3.10.1-20140818.jar etc

The first two sets are available in the server. So while creating the EAR, the jar files for the last set should only be included.

I have added the first two sets via variable method i.e. Windows --> Preferences --> Java --> Build Path --> Classpath Variable --> Selected the folder with the required jar files. But the java files in the project are not getting the corresponding packages.

But if they are directly imported in the project as External Jar files, they are accessible.

Any idea. Why?

Thanks and Regards,

Rana Brata De