Not able to extract array elements from JSON in android

Question

I have been trying to extract array elements from my JSON, but unable to, so far.

I have the following JSON:

{
    "Sample JSON": [{
            "Title": "Title1",
            "Audit": [{
                    "auditId": "01",
                    "type": "sampleType",
                    "auditText": "sampleText",
                    "answer": ["Ans1", "Ans2"]
                },
                {
                    "auditId": "02",
                    "type": "sampleType2",
                    "auditText": "sampleText2",
                    "answer": ["Ans1", "Ans2", "Ans3", "Ans4"]
                }
            ]
        },
        {
            "Title": "Title2",
            "Audit": [{
                    "auditId": "03",
                    "type": "sampleType3",
                    "auditText": "sampleText3",
                    "answer": ["Ans1", "Ans2"]
                },
                {
                    "auditId": "04",
                    "type": "sampleType4",
                    "auditText": "sampleText4",
                    "answer": ["Ans1", "Ans2", "Ans3", "Ans4"]
                }
            ]
        }
    ]
}

I want to extract the array elements of the array 'answer'.

I get exception in the line indicated in comment in the method below:

    public void getAudit(String myJSON) {

        auditList = new ArrayList<AuditList>();
        String title;
        String auditId;
        String type;
        String auditText;
        ArrayList<String> answer = new ArrayList<>();

        try {
            JSONObject jsonObj = new JSONObject(myJSON);
            JSONArray jssArray = jsonObj.getJSONArray("Sample JSON");
            int jsonArrLength = jssArray.length();
            for (int i = 0; i < jsonArrLength; i++) {
                JSONObject jsonChildObj = jssArray.getJSONObject(i);
                title = jsonChildObj.getString("Title");

                JSONArray jssArray1 = jsonChildObj.getJSONArray("Audit");
                for (int i1 = 0; i1 < jssArray1.length(); i1++) {


                    JSONObject jsonChildObj1 = jssArray1.getJSONObject(i1);
                    type = jsonChildObj1.optString("type");
                    auditText = jsonChildObj1.optString("auditText");

                    auditId = jsonChildObj1.optString("auditId");

                    JSONArray jssArray2 = jsonChildObj1.getJSONArray("answer");
                     //Getting exception in above line

                    for (int j=0; j<jssArray2.length(); j++)
                    {
                        answer.add(jssArray2.get(j).toString()) ;
                    }

                    AuditList aList = new AuditList();
                    aList.setQuesId(auditId);
                    aList.setQuesText(auditText);
                    aList.setQuesTypw(auditType);
                    aList.setAnswer(answer);
                    aList.setCategoryName(title);
                    auditList.add(aList);

                }


            }

.
.
.
.
.
}

I found the exception occurring in the line indicated above using the debugger. Couldn't find a way to extract array elements of the array 'answer'. Please help.

I have mentioned it as a comment in the above method: JSONArray jssArray2 = jsonChildObj1.getJSONArray("answer"); //Getting exception in above line — user7735493, Mar 18 '18 at 10:23
Possible duplicate of [How to parse JSON in Android](https://stackoverflow.com/questions/9605913/how-to-parse-json-in-android) — ADM, Mar 18 '18 at 10:34
What is the exception message? How about the type, auditId, auditText - are you getting the value of these correctly? — lorraine batol, Mar 18 '18 at 11:20
@lorraine: The exception message is: "org.json.JSONException: Value at answer of type java.lang.String cannot be converted to JSONArray". Sorry for the late reply. — user7735493, Mar 18 '18 at 18:32
@user7735493 it's clear from your exception, your JSON might've string value for 'answer'. Please Check or use getString() / OptString() then split using ','. — Mukeshkumar S, Mar 19 '18 at 05:34
@Maharith, how do I get individual element of 'answer' array? For eg my 'answer' array is: "answer": ["Ans1", "Ans2", "Ans3", "Ans4"]. Using "answer=jsonChildObj1.getString("answer");" gives exception as well. — user7735493, Mar 19 '18 at 06:04
@user7735493 validate your JSON in jsonlint or jsonformatter website — Mukeshkumar S, Mar 19 '18 at 06:10
@Maharith, I validated it using jsonlint. It is valid. The complete JSON is pretty long. I won't accomodate in the question. But I have put a sample of it in the question. — user7735493, Mar 19 '18 at 06:46
@user7735493 what exception you get when you tried getString(). Sorry for delay — Mukeshkumar S, Mar 19 '18 at 10:47
@user7735493 Use this [link](https://www.json-generator.com/) to show JSON — Mukeshkumar S, Mar 19 '18 at 10:55
@Maharith, this is the generated URL for my JSON: http://www.json-generator.com/api/json/get/bVnVCdnXpK?indent=2 — user7735493, Mar 19 '18 at 12:08
@user7735493 exception occurs for you coz in some place you have empty values i.e., "" and array values [] to solve your issue you have to find "" and [] — Mukeshkumar S, Mar 19 '18 at 14:55
@user7735493 if(!jsonChildObj1.get("answer").toString().equals("")){ JSONArray jssArray2 = jsonChildObj1.getJSONArray("answer"); } try this — Mukeshkumar S, Mar 19 '18 at 15:02
@user7735493 does my solution solved your trouble. If So do accept my answer ;) — Mukeshkumar S, Mar 21 '18 at 09:21

score 0 · Answer 1 · answered Mar 18 '18 at 10:56

The way I do this kind of stuff is by going to this link and then paste my json there and get my class. After that, you can go and add Gson to your gradle by adding this line to your build.gradle:

compile 'com.google.code.gson:gson:2.6.2'

Then just create an instance of the created class that you just created and convert json into your target class:

NewClass classObject = new Gson().fromJson(YOUR_JSON, NewClass.class);

score 0 · Accepted Answer · answered Mar 19 '18 at 15:05

0

if(!jsonChildObj1.get("answer").toString().equals("")){ 
   JSONArray jssArray2 = jsonChildObj1.getJSONArray("answer");
   for (int j=0; j<jssArray2.length(); j++)
   {
      answer.add(jssArray2.get(j).toString()) ;
   }
}

The exception that occurred to you because of Empty Data (""). To Prevent this validate it and getJSONArray(). refer

answered Mar 19 '18 at 15:05

Mukeshkumar S

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Thanks a lot for help ! – user7735493 Mar 20 '18 at 11:20

Not able to extract array elements from JSON in android

2 Answers2