list去除重复数据

在java里面要想去除list中的重复数据可以使用两种方式实现: 
1. 循环list中的所有元素然后删除重复

public   static   List  removeDuplicate(List list)  {
  for  ( int  i  =   0 ; i  <  list.size()  -   1 ; i ++ )  {
      for  ( int  j  =  list.size()  -   1 ; j  >  i; j -- )  {
           if  (list.get(j).equals(list.get(i)))  {
              list.remove(j);
            }
        }
      }
    return list;
} 

    public   static   List  removeDuplicate(List list)  {
      for  ( int  i  =   0 ; i  <  list.size()  -   1 ; i ++ )  {
          for  ( int  j  =  list.size()  -   1 ; j  >  i; j -- )  {
               if  (list.get(j).equals(list.get(i)))  {
                  list.remove(j);
                }
            }
          }
        return list;
    }

2. 通过HashSet踢除重复元素

public   static   List  removeDuplicate(List list)  {
    HashSet h  =   new  HashSet(list);
    list.clear();
    list.addAll(h);
    return list;
 }