SortedSet intSet=new Treeset; intset. add (new Integer(50)); intSet. add (new Integer(25)); intSet. add (new Integer(100)); intset. add (new Integer(-15); System. out. printIn(intSet. first) System. out. printIn(intSet last) SortedSet subSet=intSet tailSet(new Integer(25)); Iterator it=sub Set. iterator; while(it. hasNexto System. out. printIn(it. nextO); 15 100 25 50 100java.util.SortedSet Interface • 该接口扩展了接口Set，新增了与有序集合 相关的操作： public Object first() public Object last() public SortedSet subSet(Object min, Object max) public SortedSet headSet(Object max) public SortedSet tailSet(Object min) public Comparator comparator() SortedSet intSet=new TreeSet(); intSet.add(new Integer(50)); intSet.add(new Integer(25)); intSet.add(new Integer(100)); intSet.add(new Integer(-15)); System.out.println(intSet.first()); System.out.println(intSet.last()); SortedSet subSet=intSet.tailSet(new Integer(25)); Iterator it=subSet.iterator(); while(it.hasNext()){ System.out.println(it.next()); } -15 100 25 50 100