Get previous quarter with JodaTime and google RangeMap

JodaTimeUtils.java

import com.google.common.collect.Range;
import com.google.common.collect.RangeMap;
import com.google.common.collect.TreeRangeMap;
import org.joda.time.DateTime;
import org.joda.time.Interval;

import java.util.Iterator;
import java.util.Map;

/**
 * Created by qlehenaff on 11/23/15.
 */
public class JodaTimeUtils {

    public static Interval getQuarter(DateTime currentDate) {

        RangeMap<DateTime, Integer> quarters = buildQuartersRanges(currentDate);


        Range<DateTime> range = quarters.getEntry(currentDate).getKey();

        return new Interval(range.lowerEndpoint(), range.upperEndpoint());
    }

    public static Interval getPreviousQuarter(DateTime currentDate) {

        RangeMap<DateTime, Integer> quarters = buildQuartersRanges(currentDate);

        final int previousQuarter = getPreviousQuarterKey(currentDate, quarters);
        Range<DateTime> range = getDateTimeRange(quarters, previousQuarter);

        return new Interval(range.lowerEndpoint(), range.upperEndpoint());
    }

    protected static Range<DateTime> getDateTimeRange(RangeMap<DateTime, Integer> quarters, int previousQuarter) {
        final Iterator<Map.Entry<Range<DateTime>, Integer>> iterator = quarters.asMapOfRanges().entrySet().iterator();

        Range<DateTime> range = null;
        while (iterator.hasNext()) {
            final Map.Entry<Range<DateTime>, Integer> entry = iterator.next();
            if (entry.getValue() == previousQuarter) {
                range = entry.getKey();
                break;
            }
        }
        return range;
    }

    protected static int getPreviousQuarterKey(DateTime currentDate, RangeMap<DateTime, Integer> quarters) {
        return ((quarters.get(currentDate) - 1) +4) % 4;
    }

    protected static RangeMap<DateTime, Integer> buildQuartersRanges(DateTime currentDate) {
        RangeMap<DateTime, Integer> quarters = TreeRangeMap.create();

        // set quarters

        DateTime q0BeginDate = new DateTime(currentDate.getYear()-1, 10, 1, 0, 0, 0, 0);
        DateTime q0EndDate = new DateTime(currentDate.getYear()-1, 12, 31, 23, 59, 59, 999);

        DateTime q1BeginDate = new DateTime(currentDate.getYear(), 1, 1, 0, 0, 0, 0);
        DateTime q1EndDate = new DateTime(currentDate.getYear(), 3, 31, 23, 59, 59, 999);

        DateTime q2BeginDate = new DateTime(currentDate.getYear(), 4, 1, 0, 0, 0, 0);
        DateTime q2EndDate = new DateTime(currentDate.getYear(), 6, 30, 23, 59, 59, 999);

        DateTime q3BeginDate = new DateTime(currentDate.getYear(), 7, 1, 0, 0, 0, 0);
        DateTime q3EndDate = new DateTime(currentDate.getYear(), 9, 30, 23, 59, 59, 999);

        //add to quarters
        quarters.put(Range.closed(q0BeginDate, q0EndDate), 0);
        quarters.put(Range.closed(q1BeginDate, q1EndDate), 1);
        quarters.put(Range.closed(q2BeginDate, q2EndDate), 2);
        quarters.put(Range.closed(q3BeginDate, q3EndDate), 3);
        return quarters;
    }

}