[Java]: Unable to parse a JSON with no array / sub array in it

Question

I am using the json-simple-1.1.jar and trying to get multiple (atleast 3) values from the json as shown in the code section.

My code works for a JSON with multiple arrays but not working for simple json format.

{
"Addresses": {
    "UserName": "Rahul", 
    "Status": "Active", 
    "CreateDate": "2017-01-09T11:39:31.244Z", 
    "SecretAccessKey": "ABCD-EFGH-HIJK", 
    "AccessKeyId": "1234567"
 }
}

Following is the java logic I am trying to use:

public static String[] getValuesFromJson(String filename, Object key, int exp_sizeOfArray, String[] exp_keys) throws FileNotFoundException, IOException, ParseException { 

    String valuesFromJson[] = new String[exp_keys.length]; 

    /** Create a JSONParser object*/
    JSONParser parser = new JSONParser();

    /** Read the JSON file using parser*/
    JSONObject jsonObject = (JSONObject) parser.parse(new FileReader(
            filename));

    System.out.println("JsonObject size: "+jsonObject.keySet().size());
    for (Object object : jsonObject.keySet()) {
        System.out.println(jsonObject.get(object.toString()));
    }
    /** Get the values in JSONArray using the key*/
    JSONArray jsonArray = (JSONArray) jsonObject.get(key);
    for (int i = 0; i < jsonArray.size(); i++) {

        /** Add the individual set from JSONArray to a JSONObject */
        JSONObject subJsonObject = (JSONObject) parser.parse(jsonArray.get(i).toString());

        /** Check for expected size of array */
        if(subJsonObject.size() <= exp_sizeOfArray){
            int index=0;
            /** Check for each key value in the sub-JSONObject keySet*/
            for (Object object : subJsonObject.keySet()) {

                /** Iterate until the expected key value matches with the actual value*/
                for (int j = 0; j < exp_keys.length; j++) {

                    /** Check if the expected key matches with any of the key value*/
                    if(object.toString().trim().equals(exp_keys[j].toString().trim())){
                        System.out.println("Key: '".concat(object.toString()).concat("'\tValue: '").concat(subJsonObject.get(object)+"'"));
                        valuesFromJson[index] = subJsonObject.get(exp_keys[j]).toString();
                        index++;
                        break;
                    }
                }
            } 
        }
    }

    /** Return the value of expected key*/
    return valuesFromJson;
}

I am getting error: "org.json.simple.JSONObject cannot be cast to org.json.simple.JSONArray" on below line:

JSONArray jsonArray = (JSONArray) jsonObject.get(key);

Answer 1

You are trying to cast JSONObject to JSONArray , but there is no array. Rather get all object keys and iterate over it.

If you go to json.org( 1 ) you can find there:

An array is an ordered collection of values. An array begins with [ (left bracket) and ends with ] (right bracket). Values are separated by , (comma)

Answer 2

Voila! Done it without converting JSONObject to JSONArray

JSONObject jsonObject = (JSONObject) parser.parse(new FileReader(
            filename));
    /** Creating another JSONObject here */
    JSONObject jsonObject2 = (JSONObject) parser.parse(jsonObject.get(key).toString());
    for (Object newKey : jsonObject2.keySet()) {
        System.out.println("Key: '".concat(newKey.toString()).concat("'\tValue: '").concat(jsonObject2.get(newKey)+"'"));
    }

Thank you guys for the help!