自己寫的類要能夠添加到TreeSet中進行排序，該類需要實現Comparable接口
?1?
class?MyClass?implements?Comparable?{
?2?
????
?3?
?4?
????public?int?compareTo(Object?o)?{
?5?
????????int?i;
?6?
????????MyClass?mc?=?(MyClass)o;
?7?
???????????//比較
?8?
????????return?i;?//相等為0，大于則i>0，小于i<0
?9?
????}
10?
11?
????
12?
} 或者，另寫一個類實現Comparator，然后初始化TreeSet時，new TreeSet(new MyComparator())
?1?
public?class?MyComparator?implements?Comparator?{
?2?
?3?
????public?int?compare(Object?o1,?Object?o2)?{
?4?
????????int?i;
?5?
????????MyClass?mc1?=?(MyClass)o1;
?6?
????????MyClass?mc2?=?(MyClass)o2;
?7?
??????????//比較
?8?
????????return?i;
?9?
????}
10?
11?
}