code: public static String createPeriodString(final ReadablePeriod period) {
      String periodStr = "null";
  
      if (period == null) {
        return periodStr;
      }
  
      if (period.get(DurationFieldType.years()) > 0) {
        final int years = period.get(DurationFieldType.years());
        periodStr = years + "y";
      } else if (period.get(DurationFieldType.months()) > 0) {
        final int months = period.get(DurationFieldType.months());
        periodStr = months + "M";
      } else if (period.get(DurationFieldType.weeks()) > 0) {
        final int weeks = period.get(DurationFieldType.weeks());
        periodStr = weeks + "w";
      } else if (period.get(DurationFieldType.days()) > 0) {
        final int days = period.get(DurationFieldType.days());
        periodStr = days + "d";
      } else if (period.get(DurationFieldType.hours()) > 0) {
        final int hours = period.get(DurationFieldType.hours());
        periodStr = hours + "h";
      } else if (period.get(DurationFieldType.minutes()) > 0) {
        final int minutes = period.get(DurationFieldType.minutes());
        periodStr = minutes + "m";
      } else if (period.get(DurationFieldType.seconds()) > 0) {
        final int seconds = period.get(DurationFieldType.seconds());
        periodStr = seconds + "s";
      }
  
      return periodStr;
    }
docs: Convert ReadablePeriod Object to string
  
  @param period ReadablePeriod Object
  @return string formatted ReadablePeriod Object