I want to parse json object from firebase realtime database into arraylist (android) : I want to parse json object from firebase realtime database into arraylist<br> 
<br>
ArrayList<String> username = new ArrayList<String>();<br>
ArrayList<String> password= new ArrayList<String>();<br>
ArrayList<String> picture_profile= new ArrayList<String>();<br>
<br>
-----------------------------------json object--------------------<br>
{<br>
   "testuser1": {<br>
      "password": "123456",<br>
      "picture_profile": "default"<br>
   },<br>
   "testuser2": {<br>
      "password": "123456",<br>
      "picture_profile": "default"<br>
   }<br>
}


