Force JSONObject to JSONArray with one entry

Question

I'm retrieving some JSON data from my server. Sometimes this can come in the form of a JSONObject (one objects) or a JSONArray (multiple objects). I'm aware of how to detect if it is an array or an object... but the problem is that detecting it means that I have to have two completely separate bits of logic, one for objects and one for arrays. It's a really unclean solution that I'm surprised is not asked about more often.

What I'd like to do is: if the JSON is a JSONObject (one object), then convert it to a JSONArray (with only one entry). Then I can proceed with my normal logic for interpreting JSONArrays.

My JSON would come in like this:

{
    "Changes":
    {
        "Row":
        {
            "@ChangeId":"17192386","@Type":"U","@TableName":"Change","@PK":"g1fbb6c7-abcf-e741-846c-b499baf5845d","@ColList":"date"
        },
        "Data":
        {
            "@date":"22/05/2014 09:03:00"
        }
    }
}

Normally I have multiple records in the Row and Data objects. But in this instance, I have only one in each. My usual method is:

JSONObject jsonObj = new JSONObject(jsonString);
JSONObject changes = jsonObj.getJSONObject("Changes");
JSONArray arrChanges = changes.getJSONArray("Row");
JSONArray arrData = changes.getJSONArray("Data");

// Cycle through arrays here

This code will crash on the .getJSONArray("Row"); line.

To avoid this, after I have the changes object, I'd like to force the Row and Data objects into a JSONArray, even if there is only one value - like above, so I can continue with my normal logic. Is there a way to do this?

Answer 1

Use this method to convert JSONObject into JSONArray :

JSONObject jsonObj = new JSONObject(jsonString);
JSONObject changes = jsonObj.getJSONObject("Changes");
JSONArray arrChanges = covertJsonObjectToJsonArray(changes.get("Row"));
JSONArray arrData = covertJsonObjectToJsonArray(changes.get("Data"));


public  JSONArray covertJsonObjectToJsonArray(Object InsideArray) {

    JSONArray jsonArray;

    if (InsideArray instanceof JSONArray) {
        jsonArray = (JSONArray) InsideArray;
    } else {
        jsonArray = new JSONArray();
        jsonArray.put((JSONObject) InsideArray);
    }
    return jsonArray;
}

If JSONArray is there then it will return JSONArray, and if JSONOject is there still it will return JSONArray.

Answer 2

if I understood correctly what your problem is:

  JSONObject jsonObj = new JSONObject(jsonString);
  JSONObject changes = jsonObj.getJSONObject("Changes");
  JSONArray arrChanges = null;
  JSONArray arrData = null;
  if (isASingleJson) {
         arrChanges = new JSONArray();
         arrData = new JSONArray();
         arrChanges.put(changes.getJSONObject("Row"));
         arrData.put(changes.getJSONObject("Data"));
  } else {
         arrChanges = changes.getJSONArray("Row");
         arrData = changes.getJSONArray("Data");
  }
  //logic to handle arrays here...