code: public static void appendStringInto( String s, File outputFile ) throws IOException {
  
  		OutputStreamWriter fw = null;
  		try {
  			fw = new OutputStreamWriter( new FileOutputStream( outputFile, true ), StandardCharsets.UTF_8 );
  			fw.append( s );
  
  		} finally {
  			Utils.closeQuietly( fw );
  		}
  	}
docs: Appends a string into a file.
  
  @param s the string to write (not null)
  @param outputFile the file to write into
  @throws IOException if something went wrong