[Java] Java比较器实现方法项目案例

public class entity implements comparable<entity> {
  @override
  public int compareto(entity o) {
  return 0;
  }
}

public class entitycomparator implements comparator<entity> {
  @override
  public int compare(entity o1, entity o2) {
  return 0;
  }
}

public class record {
  //状态
  private string state;
  //时长
  private string time;
  public record(string state, string time) {
  this.state = state;
  this.time = time;
  }
  public string getstate() {
  return state;
  }
  public string gettime() {
  return time;
  }
  @override
  public string tostring() {
  return "record{" +
    "state='" + state + '\'' +
    ", time='" + time + '\'' +
    '}';
  }
}

public class recordcomparator implements comparator<record> {
  @override
  public int compare(record o1, record o2) {
  final int statecompare = o1.getstate().compareto(o2.getstate());
  if (statecompare == 0) {
    return o1.gettime().compareto(o2.gettime());
  }
  return statecompare;
  }
}

public class recordtimedesccomparator implements comparator<record> {
  @override
  public int compare(record o1, record o2) {
  final int statecompare = o1.getstate().compareto(o2.getstate());
  if (statecompare == 0) {
    return o2.gettime().compareto(o1.gettime());
  }
  return statecompare;
  }
}

record record1 = new record("通话中", "00:01:08");
record record2 = new record("空闲", "00:18:02");
record record3 = new record("通话中", "00:04:04");
record record4 = new record("空闲", "00:01:57");
list<record> recordlist = new arraylist<>();
recordlist.add(record1);
recordlist.add(record2);
recordlist.add(record3);
recordlist.add(record4);
system.out.println("排序前：" + recordlist);
collections.sort(recordlist, new recordcomparator());
system.out.println("排序后【时间正序】：" + recordlist);
recordlist = new arraylist<>();
recordlist.add(record1);
recordlist.add(record2);
recordlist.add(record3);
recordlist.add(record4);
system.out.println("排序前：" + recordlist);
collections.sort(recordlist, new recordtimedesccomparator());
system.out.println("排序后【时间倒序】：" + recordlist);

排序前：[record{state='通话中', time='00:01:08'}, record{state='空闲', time='00:18:02'}, record{state='通话中', time='00:04:04'}, record{state='空闲', time='00:01:57'}]
排序后【时间正序】：[record{state='空闲', time='00:01:57'}, record{state='空闲', time='00:18:02'}, record{state='通话中', time='00:01:08'}, record{state='通话中', time='00:04:04'}]
排序前：[record{state='通话中', time='00:01:08'}, record{state='空闲', time='00:18:02'}, record{state='通话中', time='00:04:04'}, record{state='空闲', time='00:01:57'}]
排序后【时间倒序】：[record{state='空闲', time='00:18:02'}, record{state='空闲', time='00:01:57'}, record{state='通话中', time='00:04:04'}, record{state='通话中', time='00:01:08'}]