I would make use of [Denodo4E](https://community.denodo.com/docs/html/browse/7.0/denodo4e/install_denodo4e/install_denodo4e#installing-denodo4e) extension to build a Custom Stored Procedure in Java using Eclipse. Then, I would deploy (using **deploy extension**) this Custom Stored Procedure directly into the Virtual DataPort Server.
In cases where I want to retrieve the Custom Stored Procedure as a **jar file**, I would **export** the project as a Jar file by choosing **Export > Java > Jar file** option. Then, I would import this Jar file manually into the Virtual DataPort using the [File > Extensions Management](https://community.denodo.com/docs/html/browse/7.0/vdp/administration/importing_extensions/importing_extensions#importing-extensions).
You could have a look at the [Developing Stored Procedures](https://community.denodo.com/docs/html/browse/7.0/vdp/developer/developing_extensions/developing_stored_procedures/developing_stored_procedures#developing-stored-procedures) section of Virtual DataPort Developer Guide for more information.
Hope this helps!