title: How to write on file having its url from a servlet
body: <p>How can I write on a file having its URL such as <code>/WebContent/Database/myFile.json</code> from a Servlet?</p>
  
  <p>Constraint: I can't use absolute paths to write on this file.</p>
  
  <p>Additional info: the servlet receives a string as a POST parameter, then her should write this string on a file located in the same servlet context.</p>