code: public static void put(Writer writer, Date value) throws IOException {
  		if (value == null) {
  			writer.write("null");
  		} else {
  			writer.write(String.valueOf(value.getTime()));
  		}
  	}
docs: Writes the given value with the given writer.
  @param writer
  @param value
  @throws IOException
  @author vvakame