java 删除List 中的重复数据

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)  {
HashSet h  =   new  HashSet(list);
list.clear();
list.addAll(h);
return list;
}

def list = [1, 2, 3, 2, 4, 1, 5]
list.unique()  // [1, 2, 3, 4, 5]