title: SharePoint REST API for Fetching custom Metadata Columns
body: <p>I am Developing a plugin that exports Documents to SharePoint Repository after processing them. Along with the document, I need to send values for Custom Metadata columns defined in SharePoint.</p>
  
  <p>I have figured out how to send across Files and Metadata to a specified location.</p>
  
  <p>Problem: Initially, I do not know what custom metadata columns are available in the given folder. 
  Could someone shed light on any REST webservice that can fetch the available Metadata Columns for a given location in the repository.</p>
  
  <p>Note: I am using pure Java for REST Requests using Apache HTTP Client. </p>