一个LIST中的重复与不重复

去掉一个LIST的重复

Set someSet = new HashSet(list);   
     Iterator iterator = someSet.iterator();     
     List tempList = new ArrayList();     
     int i = 0;     
     while(iterator.hasNext()){                 
       tempList.add(iterator.next().toString());     
       i++;     
     }     
     return tempList;   

另外一种情况

Integer[] aa={-1,4,5};
Integer[] ab={-15,1,3,4,5,7,8,9,10,15};
List<Integer> list1 = Arrays.asList(aa);  
List<Integer> list2=Arrays.asList(ab);
List<Integer> list3=new ArrayList<Integer>();
//求重复 
list3.addAll(list2);
list3.retainAll(list1);
System.out.println(list3);
//求不重复
List<Integer> list4=new ArrayList<Integer>();
list4.addAll(list1);
list4.addAll(list2);
list4.removeAll(list3);
System.out.println(list4);