TimeUtils.java

package org.npr.android.util;

/**
 * http://stackoverflow.com/questions/3859288/how-to-calculate-time-ago-in-java#5062810
 * Author: David Blevins (http://stackoverflow.com/users/190816/david-blevins)
 */


import static org.npr.android.util.TimeUnit.MILLISECONDS;

public class TimeUtils {

  /**
   * Converts time to a human readable format within the specified range
   *
   *
   *
   * @param duration the time in milliseconds to be converted
   * @param max      the highest time unit of interest
   * @param min      the lowest time unit of interest
   * @return A human readable time expression
   */
  public static String formatMillis(long duration, TimeUnit max, TimeUnit min) {
    StringBuilder res = new StringBuilder();

    TimeUnit current = max;

    while (duration > 0) {
      long temp = current.convert(duration, MILLISECONDS);

      if (temp > 0) {
        duration -= current.toMillis(temp);
        res.append(temp).append(" ").append(current.name().toLowerCase());
        if (temp < 2) res.deleteCharAt(res.length() - 1);
        res.append(", ");
      }

      if (current == min) break;

      current = TimeUnit.values()[current.ordinal() - 1];
    }

    // clean up our formatting....

    // we never got a hit, the time is lower than we care about
    if (res.lastIndexOf(", ") < 0) return "0 " + min.name().toLowerCase();

    // yank trailing  ", "
    res.deleteCharAt(res.length() - 2);

    //  convert last ", " to " and"
    int i = res.lastIndexOf(", ");
    if (i > 0) {
      res.deleteCharAt(i);
      res.insert(i, " and");
    }

    return res.toString();
  }
}