Getting NullPointerException while parsing JSONArray

Question

Working on JSON for the first time. The problem is -

I am getting null pointer exception even after handling the empty json array. I have created a josn file file in which there is an empty array. my json file is like-

{
   "name" :"jsonObject",

   "myArray" : []
}

For parsing I am using json.simple-1.1.1.jar. My java code is -

JSONParser parser = new JSONParser();
        JSONObject rootObj = (JSONObject) parser.parse(new FileReader(filePath));           

        String str = (String) rootObj.get("name");

        JSONArray array = (JSONArray)rootObj.get("array");

        if(array.isEmpty())
            System.out.println("array is null");

In json file the array will be null sometimes and sometimes not. What is the proper way to handle it?

Maybe it's just a copy-paste typo, but shouldn't it be rootObj.get("myArray")? — Laura
– Laura, Commented Apr 23, 2014 at 12:26

theHacker · Accepted Answer · 2014-04-23 12:25:52Z

2

Your member's name is myArray not array. This works:

JSONArray array = (JSONArray) rootObj.get("myArray");

To check if the member is there use has():

if(rootObj.has("myArray")) {
    JSONArray array = rootObj.getJSONArray("myArray"); // getJSONArray avoids cast :-)
    // ...
}

See: http://www.json.org/javadoc/org/json/JSONObject.html#has%28java.lang.String%29

answered Apr 23, 2014 at 12:25

theHacker

4,0431 gold badge23 silver badges36 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Getting NullPointerException while parsing JSONArray

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related