Why does my Spring project return A JSONArray text must start with '[' at 1?

Question

I'm new to Spring Boot and json so forgive me if a silly question. I'm trying to read in my json file, convert it to a JSONObject , then convert this to a JSONArray . I've commented out the two lines which do this as I tried going from reading the file to the Array instead. My JSON file starts with a [ so I'm unsure why I get this error.

Exception in thread "main" org.json.JSONException: A JSONArray text must start with '[' at 1 [character 2 line 1]

InputStream inputStream = TypeReference.class.getResourceAsStream("/json/req.json");        
List<PIECase> allCases = new ArrayList<PIECase>();              
InputStream rawJson = inputStream;
//JSONObject jsonObject = new JSONObject(rawJson);
//JSONArray jsonArray = jsonObject.getJSONArray("PIECases");
JSONArray jsonArray = new JSONArray(rawJson.toString());

for(int i =0; i < jsonArray.length(); i++) {
    //the JSON data we get back from array as a json object
    JSONObject jsonPIECases = jsonArray.getJSONObject(i);

    // more code
}

req.json

[
    {
        "PIECases": {
            "PIECases": [
                {
                    "Case_ID": "1",
                    "SortCode": "123456",
                    "AccountNumber": "12345678",
                    "Amount": "50",
                    "DateOfPayment": "2019-07-29"
                },
                {
                    "Case_ID": "2",
                    "SortCode": "123456",
                    "AccountNumber": "12345678",
                    "Amount": "50",
                    "DateOfPayment": "2019-07-29"
                }
            ]
        }
    }
]

Answer 1

rawJson.toString() does not return the json content but just the result of default Object#toString() method of the InputStream , use;

JsonReader jsonReader = Json.createReader(inputStream);
JsonArray array = jsonReader.readArray();
jsonReader.close();

from JsonArray