com.elastisys.scale.commons.util.time.TimeUtils Maven / Gradle / Ivy

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package com.elastisys.scale.commons.util.time;

import org.joda.time.DateTime;
import org.joda.time.Duration;
import org.joda.time.Period;
import org.joda.time.format.PeriodFormatter;
import org.joda.time.format.PeriodFormatterBuilder;

/**
 * Convenience methods for working with time.
 */
public class TimeUtils {

	/**
	 * Null-safe comparison that compares if two {@link DateTime} instances
	 * represent the same time instant. In the case of two non-null
	 * objects, the semantics is the same as for {@link DateTime#isEqual(long)}.
	 * That is, the comparison is based solely on milliseconds, which allows
	 * timestamps with different time zones to be correctly compared (which is
	 * not the case with {@link DateTime#equals(Object)}).
	 *
	 * @param instant1
	 *            First {@link DateTime} instance. May be null.
	 * @param instant2
	 *            Second {@link DateTime} instance. May be null.
	 * @return true if the {@link DateTime} instances represent the
	 *         same time instant.
	 *
	 */
	public static boolean equal(DateTime instant1, DateTime instant2) {
		return (instant1 == instant2)
				|| ((instant1 != null) && instant1.isEqual(instant2));
	}

	/**
	 * Returns a human-readable string representation of a {@link Duration},
	 * which expresses the duration in hours, minutes and seconds using the
	 * highest possible units.
	 *
	 * @param duration
	 * @return A duration such as "48 hours, 10 minutes, 1 second"
	 */
	public static String durationAsString(Duration duration) {
		if (duration.isShorterThan(new Duration(1))) {
			return "0 seconds";
		}

		PeriodFormatter formatter = new PeriodFormatterBuilder()
				.printZeroNever().appendHours().appendSuffix(" hour", " hours")
				.appendSeparator(", ").printZeroNever().appendMinutes()
				.appendSuffix(" minute", " minutes").appendSeparator(", ")
				.printZeroNever().appendSeconds()
				.appendSuffix(" second", " seconds").toFormatter();
		new Period(duration.getStandardDays());
		return formatter.print(duration.toPeriod());
	}
}