Modifying/Updating values inside a jsonArray?

Question

What I want to do is at a particular index position change/replace a value inside a json array.After going through the documentation at http://www.json.org/javadoc/org/json/JSONArray.html I found out that jsonArray does not have a getIndex() method.In this situation how do I update my json array at a given index position. This is the method that creates a json array in my android code.

private void createJsonArray() {
        billType = (invEstSwitch.isChecked() ? textViewEstimate : textViewInvoice)
                .getText().toString();
        String invNumber = textViewInvNo.getText().toString();
        String bcode = barCode.getText().toString();
        String description = itemDesc.getText().toString();
        String wt = weightLine.getText().toString();
        String rateAmt = rateAmount.getText().toString();
        String making = makingAmount.getText().toString();
        String netr = netRate.getText().toString();
        String iTotal = itemtotal.getText().toString();
        String vatAmt = textViewVat.getText().toString();
        String sumAmt = textViewSum.getText().toString();
        String crtDate = textViewCurrentDate.getText().toString();
        try {
            jsonObject.put("custInfo", custSelected.toString());
            jsonObject.put("invoiceNo", invNumber);
            jsonObject.put("barcode", bcode);
            jsonObject.put("description", description);
            jsonObject.put("weight", wt);
            jsonObject.put("rate", rateAmt);
            jsonObject.put("makingAmt", making);
            jsonObject.put("net_rate", netr);
            jsonObject.put("itemTotal", iTotal);
            jsonObject.put("vat", vatAmt);
            jsonObject.put("sum_total", sumAmt);
            jsonObject.put("bill_type", billType);
            jsonObject.put("date", crtDate);


        } catch (JSONException e) {
            e.printStackTrace();
        }
        try {
            itemSelectedJson.put(index, jsonObject);
            index++;
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

And this is the code that I use to update my json array which contains a json object.

  try {
                itemSelectedJson.getJSONObject(i).put("net_rate",netChange);
                Log.d("NETRATE_TW",itemSelectedJson.toString());
            } catch (JSONException e) {
                e.printStackTrace();
            }

Now the problem with this code is it updates the jsonArray everytime a new item is added to the code.So the first object values are the same as the last object.

Also note that I am using this code inside a text watcher.So the afterTextchanged() method looks like this.

  @Override
        public void afterTextChanged(Editable s) {
            String netChange = netRate.getText().toString();
            final int row_id = (int) newRow.getTag();

            if ((row_id<0) || (row_id> itemSelectedJson.length())){
                return;
            }

            try {
                itemSelectedJson.getJSONObject(row_id-1).put("net_rate",netChange);
                Log.d("NETRATE_TW",itemSelectedJson.toString());
            } catch (JSONException e) {
                e.printStackTrace();
            }
  }
    };

This is the snapshot of what my database looks like.

Answer 1

A jSONObject(which is a collection of name,value pairs) can be converted into a JSONArray which is an ordered array of the "values" in the JSONObject.

This can be done using the .toJSONArray() method.

When you need to replace/update the JSONArray, you may use the method .put(int index, java.util.Map value)

Unlike how you are doing at present, i.e getting the object and setting a new key and value.

http://www.json.org/javadoc/org/json/JSONArray.html#put(int, java.util.Map)