TreeSet中自定义Comparator实现降序

 @Test
     public void test1() {
         TreeSet ts = new TreeSet<Integer>(new MyComparator());
         ts.add(3);
         ts.add(2);
         ts.add(100);

         for(Iterator i = ts.iterator();i.hasNext();)
         {
             System.out.println(i.next());
             }
         }
 }

 class MyComparator implements Comparator<Integer> {

     public int compare(Integer o1, Integer o2) {
         // TODO Auto-generated method stub
         //降序排列
         if(o1>o2) return -1;
         if(o1==o2)return 0;else return 1;
     }