In addition to Tim’s comment, if you are looking at trying to load files into a Mendix application, have a look at the Community Commons module in the App Store. For example, the StringFromFile action will load a file from the resources folder into a String. Other actions may also be of use.
Java runs serverside, and there is no "C:/Users/destination.jcoDestination"
on the server.
More info here: https://docs.mendix.com/studio/page-editor-widgets-images-and-files