code: public File getOutputFile(String relativeServerPath) {
          if (relativeServerPath == null)
              return outputDir;
          else
              return new File(outputDir, relativeServerPath);
      }
docs: Allocate a file in the server output directory, e.g.
  server-data/serverName/relativeServerPath
  
  @param relativeServerPath
  relative path of file to create in the server directory
  @return File object for relative path, or for the server directory itself
  if the relative path argument is null