Failed to convert String to jsonArray-CodePudding

`I have a PHP code that 1st calculates if the image parameters retrieval from DB was successful or not and then inserts into response the 3 parameters (Id,name,url) for each image. Then it returns json format response. I am collecting that response in android in the form of String then I need to convert it to jsonArray. While conversion, I get exception.

PHP CODE:

<?php 
 
 //Importing dbdetails file 
 require_once 'dbDetails.php';
 
 //connection to database 
 $con = mysqli_connect(HOST,USER,PASS,DB) or die('Unable to Connect...');
 
 //sql query to fetch all images 
 $sql = "SELECT * FROM MyImages";
 
 //getting images 
 $result = mysqli_query($con,$sql);
 
 //response array 
 $response = array(); 
 $response['error'] = false; 
 $response['images'] = array(); 
 
 //traversing through all the rows 
 while($row = mysqli_fetch_array($result)){
 $temp = array(); 
 $temp['id']=$row['id'];
 $temp['name']=$row['name'];
 $temp['url']=$row['url'];
 array_push($response['images'],$temp);
 }
 //displaying the response 
 echo json_encode($response);
 ?>

result is the response from php code in the below code
android code:

@Override protected void onPostExecute(String result) {
        super.onPostExecute(result);
        if (pd.isShowing()){
            pd.dismiss();
        }
        txtJson.setText(result);
        try {
            JSONArray jsonArr = new JSONArray(result);
            showGrid(jsonArr);
        } catch (JSONException e) {
            e.printStackTrace();
            txtJson.setText("Exception in jsonArry");
        }
    }

Then how to do it properly?

The response string is->

{"error":false,"images":[{"id":"1","name":"1","url":"https:\/\/swulj.000webhostapp.com\/AndroidUploadImage\/uploads\/1.jpg"},{"id":"2","name":"2","url":"https:\/\/swulj.000webhostapp.com\/AndroidUploadImage\/uploads\/2.jpg"},{"id":"3","name":"3","url":"https:\/\/swulj.000webhostapp.com\/AndroidUploadImage\/uploads\/3.jpg"},{"id":"4","name":"ygff","url":"https:\/\/swulj.000webhostapp.com\/AndroidUploadImage\/uploads\/4.jpg"}]}

Is this in proper json format? What should I do?

CodePudding user response：

Your android code should be like this

protected void onPostExecute(String result) {
    super.onPostExecute(result);
    if (pd.isShowing()){
        pd.dismiss();
    }
    txtJson.setText(result);
    try {
        JSONObject jsonObj = new JSONObject(result);
        showGrid(jsonObj.optJsonArray("images"));
    } catch (JSONException e) {
        e.printStackTrace();
        txtJson.setText("Exception in jsonArry");
    }
}

CodePudding user response：

As the string response is not surrounded by "[" and "]", I surrounded it and no exception occurs.
CODE:

protected void onPostExecute(String result) {
            super.onPostExecute(result);
            if (pd.isShowing()){
                pd.dismiss();
            }
            txtJson.setText(result);
            try {
                String res = "["   result   "]";
                JSONArray jsonArr = new JSONArray(res);
                showGrid(jsonArr);
                /*JSONObject jsonObj = new JSONObject(result);
                showGrid(jsonObj.optJsonArray("images"));*/
            } catch (Exception e) {
                e.printStackTrace();
                txtJson.setText("Exception in jsonArry");
            }
        }