Collections方法使用自定义Comparator对象排序。

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;
/*来自 nowjava - 时  代  Java*/

public class Main {

  public static void main(String[] args) {

    List<Time> list = new ArrayList<>(); // create List


    list.add(new Time(6, 24, 34));

    list.add(new Time(18, 14, 58));

    list.add(new Time(16, 15, 34));

    list.add(new Time(12, 14, 58));

    list.add(new Time(6, 24, 22));/** 来自 NowJava.com**/


    // output List elements

    System.out.printf("Unsorted array elements:%n%s%n", list);


    // sort in order using a comparator

    Collections.sort(list, new TimeComparator());


    // output List elements

    System.out.printf("Sorted list elements:%n%s%n", list);

  }

}


class Time {

  private int hour; // 0 - 23

  private int minute; // 0 - 59

  private int second; // 0 - 59


  // Time2 no-argument constructor:

  // initializes each instance variable to zero

  public Time() {

    this(0, 0, 0); // invoke Time2 constructor with three arguments

  }


  // Time2 constructor: hour supplied, minute and second defaulted to 0

  public Time(int h) {

    this(h, 0, 0); // invoke Time2 constructor with three arguments

  }


  // Time2 constructor: hour and minute supplied, second defaulted to 0

  public Time(int h, int m) {

    this(h, m, 0); // invoke Time2 constructor with three arguments

  }


  // Time2 constructor: hour, minute and second supplied

  public Time(int h, int m, int s) {

    setTime(h, m, s); // invoke setTime to validate time

  }


  // Time2 constructor: another Time2 object supplied

  public Time(Time time) {

    // invoke Time2 three-argument constructor

    this(time.getHour(), time.getMinute(), time.getSecond());

  }


  // Set Methods

  // set a new time value using universal time;

  // validate the data

  public void setTime(int h, int m, int s) {

    setHour(h); // set the hour

    setMinute(m); // set the minute

    setSecond(s); // set the second

  }


  // validate and set hour

  public void setHour(int h) {

    if (h >= 0 && h < 24)

      hour = h;

    else

      throw new IllegalArgumentException("hour must be 0-23");

  }


  // validate and set minute

  public void setMinute(int m) {

    if (m >= 0 && m < 60)

      minute = m;

    else

      throw new IllegalArgumentException("minute must be 0-59");

  }


  // validate and set second

  public void setSecond(int s) {

    if (s >= 0 && s < 60)

      second = ((s >= 0 && s < 60) ? s : 0);

    else

      throw new IllegalArgumentException("second must be 0-59");

  }


  // get hour value

  public int getHour() {

    return hour;

  }


  // get minute value

  public int getMinute() {

    return minute;

  }


  // get second value

  public int getSecond() {

    return second;

  }


  // convert to String in universal-time format (HH:MM:SS)

  public String toUniversalString() {

    return String.format("%02d:%02d:%02d", getHour(), getMinute(), getSecond());

  }


  // convert to String in standard-time format (H:MM:SS AM or PM)

  public String toString() {

    return String.format("%d:%02d:%02d %s",