List set to remove duplicate data

[Conversion] Java list set to remove duplicate data

1. Loop all elements in the list and delete duplicates

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. Use hashset to remove duplicate elements

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

3. Delete repeated elements in the arraylist in order

// Delete repeated elements in the arraylist in the order of public static void removeduplicatewithorder (list) {set = new hashset (); List newlist = new arraylist (); for (iterator iter = List. iterator (); ITER. hasnext ();) {object element = ITER. next (); If (set. add (element) newlist. add (element);} List. clear (); list. addall (newlist); system. out. println ("Remove duplicate" + list );}

4. traverse the objects in the list and use list. contain (). If it does not exist, store the objects in another list set.

public static List removeDuplicate(List list){          List listTemp = new ArrayList();          for(int i=0;i<list.size();i++){              if(!listTemp.contains(list.get(i))){                  listTemp.add(list.get(i));              }          }          return listTemp;      }  

Reprinted: http://blog.csdn.net/u011728105/article/details/46594963

List set to remove duplicate data