code: public static Integer parserInteger(JsonPullParser parser) throws IOException,
  			JsonFormatException {
  
  		State eventType = parser.getEventType();
  		if (eventType == State.VALUE_NULL) {
  			return null;
  		} else if (eventType == State.VALUE_LONG) {
  			return (int) parser.getValueLong();
  		} else {
  			throw new IllegalStateException("unexpected state. expected=VALUE_LONG, but get="
  					+ eventType.toString());
  		}
  	}
docs: Parses the current token as an integer.
  @param parser
  @return {@link Integer}
  @throws IOException
  @throws JsonFormatException
  @author vvakame