How to replace a JSON value stored in a JSON file and use that in a Rest Assured test

Question

I have a set of input data files in JSON and I am trying to replace a value present in a JSON file and use that value to do a post request in restAssured

The JSON file has

{
    "items": [
        {
            "item_ref": 241,
            "price": 100
        }
    ]
}

jsonbody below is a String of the above JSON file

This is the code that fails:

JSONObject jObject  = new JSONObject(jsonbody);
        jObject.remove("item_ref");
        jObject.put("item_ref","251");
        System.out.println(jObject);

This is what I am getting:

{"item_ref":"251","items":[{"item_ref":241,"price":100}]}

What I want is {"items":[{"item_ref":251,"price":100}]}

I also tried

JSONObject jObject  = new JSONObject(jsonbody);
        jObject.getJSONObject("items").remove("item_ref");
        jObject.getJSONObject("items").put("item_ref","251");
        System

But it says JSONObject["items"] is not a JSONObject.

All I need is to replace the 241 with 251. Is there an easier way to do this?

In general if we have a predefined JSON body file and if we want to replace some of the values in the body and use that in our POST calls within RestAssured, is there any easier way to do it?

Answer 1

The problem is - field item_ref and price are not in JSON Object as you think they are. They are in JSON Array which contains JSON Objects. In order to modify that value, you have to get elements of the array and THEN execute very similar code you wrote.

Check this out:

JSONObject jObject  = new JSONObject(jsonbody);
JSONArray array = jObject.getJSONArray("items");
JSONObject itemObject = (JSONObject) array.get(0); //here we get first JSON Object in the JSON Array
itemObject.remove("item_ref");
itemObject.put("item_ref", 251);

The output is:

{"items":[{"item_ref":251,"price":100}]}