How to display a JSON file in a TextView

Question

I'm very new to Android and having a lot of trouble understanding JSON. I have a separate JSON file with my values written out but no idea how to actually display those strings in an Android app.

Any comprehensive tutorials or basic-level explanations are very welcome. Thanks!

Answer 1

First of all try to understand AsyncTask also. It allows the user to perform a long background operations and to show the results back to the user in the MainUI Thread. You can perform JSON parsing and get values which is stored inside the JSON file via AsyncTask.

JSON is very light, easy to understand and it's the best alternative to XML. To parse your JSON file you need to know about JSONArray and JSONObject. In a JSON file , square bracket [ represents a JSON array and curly braces { represent the JSON objects. JSON is structured with Key and Value pairs. Get your string values with getString("key");and then just display it into TextView

JSONArray - It contains many JSON Objects.

JSONObjects - It contains key and value pairs.

1. [ -> It represents the JSON Array
2. { -> It represents the JSON Object

Two methods getJSONArray() and getJSONObject() are mainly used in the JSON to represent the json node.

Get your JSON Array node.

JSONArray booksArray = jsonObj.getJSONArray("books");

JSON Code :

 {
   "books": [                            //JSON array

      {                                  //represents JSON Object
         "id":"440",                     //Key and Value pair
         "edition": "Fourth",
         "language": "Java",
      },

      {
         "id":"407",
         "edition": "second",
         "language": "Python",

      }

   ]
}

Above code has one JSON Object(books) and one JSON Array it holds two json objects. See this for JSON Parsing in Android.

You can also upload your JSON file for free pastebin and view your JSON file as tree structure with JsonViewer

NOTICE : Comments are not officially supported in JSON. So I just added comments like in JAVA.