title: Liferay document library API - help required for a beginner
body: <p>I am completely new to Liferay and unfortunately have limited knowledge of portlet, liferay APIs etc. 
  I have been asked to use liferay's document library API to add documents in one of our portlet.
  We are using 5.2.3 version currently. I could find the javadocs which has methods like addFileEntry, addFile in classes such as DLFileEntryLocalServiceUtil, DLLocalServiceUtil etc, but having a very hard time to understand which method to use or which class to use. </p>
  
  <p>Also, most of these APIs takes parameters such as userId, groupId, companyId etc etc. From where can I get that?</p>
  
  <p>I know I am asking some very basic questions and should first try to understand the key concepts behind liferay, but unfortunately have been given very limited time :(. My bad luck.</p>
  
  <p>It would be really helpful, if anyone can provide some sample code base with some explanation on it or guide me to any link.</p>
  
  <p>Thanks,
  Ashish </p>