To remove key from hashmap and rearrange keys when used in recycler view

Question

Please any one can help how to remove particular key from hashmap and then rearrange the keys in hashmap accordingly.

Below is my code.

Set<Integer> integerSet = hashMap.keySet();
                int removekey = pos;
                ArrayList<Integer> integers = new ArrayList<>();
                for (Integer integer : integerSet) {
                    if (integer > removekey) {
                        integers.add(integer);
                    }
                }

                for (Integer integer : integers) {
                    if (hashMap.containsKey(integer)) {
                        AddCardPojo pojo = hashMap.get(integer);
                        pojo.setImagCard(cardImage[integer - 1]);
                        hashMap.remove(integer);
                        hashMap.put(integer - 1, pojo);
                    }
                }[![enter image description here][1]][1]

I have attached screenshot of error

what do you mean by re arrange? can you explain what you are trying to do? — Suraj Rao, Dec 08 '16 at 05:53
I mean when I add more than 7 items in hashmap and try to remove 4th item from hashmap then it gives me error "ArrayIndexOutOfBoundsException" — Alps Rana, Dec 08 '16 at 06:07
pojo.setImagCard(cardImage[integer - 1]); is probably where you have the exception — Suraj Rao, Dec 08 '16 at 06:17

score 0 · Answer 1 · edited May 23 '17 at 11:52

0

You can directly remove a key value pair,you can directly do

 hashMap.remove(removeKey);

as for 're arranging keys in hashmap', it is a data structure which makes no guarantees of order of data. Check this answer for more

If you need a particular order as per integer, you could use arraylist

edited May 23 '17 at 11:52

Community

1
1

answered Dec 08 '16 at 06:02

Suraj Rao

29,388
11
94
103

score 0 · Answer 2 · answered Dec 08 '16 at 12:12

Finally it could be done. Below is my answer.

               hashMap.remove(key);

               List<AddCardPojo> hashMapsList=new ArrayList<>();

                Iterator it = hashMap.entrySet().iterator();
                while (it.hasNext()) {

                    Map.Entry pair = (Map.Entry)it.next();
                    hashMapsList.add((AddCardPojo) pair.getValue());
                }

                hashMap = new HashMap<>();
                for(int i=0; i<hashMapsList.size();i++){
                    hashMap.put(i,hashMapsList.get(i));
                }

To remove key from hashmap and rearrange keys when used in recycler view

2 Answers2