How to filter data from Json in android?

Question

i am getting the data in json form like

{\"Users\":[
{\"category_id\":\"1\",\"user_email\":\"a@a.com\"},
{\"category_id\":\"5\",\"user_ema         


        

Answer 1

First you need to create your variables in your activity

//URL to get JSON
private static String url = "your url to parse data";

//JSON Node Names
private static final String TAG_USERS = "users";
private static final String TAG_CATEGORY_ID = "category_id";
private static final String TAG_USER_EMAIL = "user_email";

// Data JSONArray
JSONArray users = null;

//HashMap to keep your data
ArrayList> userList;

inside onCreate() function instantiate your userList

userList = new ArrayList>();

then you need to parse your data and populate this ArrayList in doInBackground() function

//Create service handler class instance
ServiceHandler sh = new ServiceHandler();

//Url request and response
String jsonStr = sh.makeServiceCall(url, ServiceHandler.GET);
Log.d("Response: ", "> " + jsonStr);

if(jsonStr != null) {
    try {
        JSONObject jsonObj = new JSONObject(jsonStr);

        //Get Json Array Node
        users = jsonObj.getJSONArray(TAG_USERS);

        // Looping through all data
        for(int i = 0; i < users.length(); i++) {
            JSONObject u = users.getJSONObject(i);

            String category_id = u.getString(TAG_CATEGORY_ID);
            String user_email = u.getString(TAG_USER_EMAIL);

            // Temporary HashMap for single data
            HashMap user = new HashMap();

            // Adding each child node to Hashmap key -> value
            user.put(TAG_CATEGORY_ID, category_id);
            user.put(TAG_USER_EMAIL, user_email);

            //Adding user to userList
            userList.add(user);
        }
    }catch (JSONException e) {
        e.printStackTrace();
    }
} else {
    Log.e("ServiceHandler", "Couldn't get any data from url");
}

Now you have your data stored in your userList. You can use your userList however you want. To get the category_id field in the list you can use this syntax

// i being the counter of your loop
String catId = userList.get(i).get("category_id");
if(catId == 3) {
    ... your code
}