CODEWITHSUNDEEP
javaandroidjsonarraylist
sger
sger

Reputation: 740

ArrayList group items

I have a simple json file 

{"name":"item1",
 "category":"work",
 "id":1},
{"name":"item2",
 "category":"work",
 "id":2},
{"name":"item3",
 "category":"work",
 "id":3}
{"name":"item4",
 "category":"home",
 "id":4}

converted to ArrayList i want to group items by category like the following tree view

work -item1 -item2 -item3

home -item4

Any ideas?

    private List<Item> item = new ArrayList<Item>();

    try {

    JSONObject responseObject = new JSONObject(response);
    JSONObject itemsObject = responseObject.getJSONObject("items");

    Iterator<?> keysIterator = itemsObject.keys();

    while(keysIterator.hasNext()) {
         String keyString = (String)keysIterator.next();
         JSONObject coupon = couponsObject.getJSONObject(keyString);

         Item item = new Item();
         item.setName(item.getString("name"));
         item.setCategory(item.getString("category"));
         item.setID(item.getString("id"));
         itemList.add(item);
     }

   } catch (Exception e) {
     e.printStackTrace();
   }

   adapter.notifyDataSetChanged();

Upvotes: 1

Views: 2387

Answers (2)

user2590934
user2590934

Reputation:

a little bit logical. try using recursion if the categories and number of objects coming in are dynamic

public void itemSort(String response)
{
   map = new HashMap<>();
   JSONObject obj = new JSONObject("{\"list\":[" + messageJson + "]}");
   JSONArray arrrr = obj.getJSONArray("list");

   getItems (arrrr, 0);
   System.out.println(map + "");
}

private HashMap<String, String> map;
    private void getItems (JSONArray ar, int counter)
    {
        if (counter < ar.length())
        {
            JSONObject j = (JSONObject) ar.get(counter);
            if (!map.containsKey(j.get("category").toString()))
            {
                map.put(j.get("category").toString(), j.get("name").toString());
            } else
            {
                map.put(j.get("category").toString(), map.get(j.get("category").toString()) 
                        + "," + j.get("name").toString());
            }
            counter++;
            getItems (ar, counter);
        }
    }

Upvotes: 0

user902383
user902383

Reputation: 8640

as @Luiggi suggest, use Map map will reflect your tree view structure.

all what you need to do is change your code little bit, instead List define map

Map> items = new HashMap<>();

and other change is in your while loop where you are creating item

     Item item = new Item();
     item.setName(item.getString("name"));
     item.setCategory(item.getString("category"));
     item.setID(item.getString("id"));

     List<Item> itemList= items.get(item.getCategotry());
     if (itemList ==null){
     itemList = new ArrayList<>();
         items.put(item.getCategotry(),itemList);
     }
     itemList.add(item);

Upvotes: 0

Related Questions