JSONArray to String in java

Question

I have an JSONArray that looks like this:

enter image description here

how can i convert that to a string?

if i try:

json.toString();

the string is:

["package.package.ChecklistModels.ChecklistAnswer@405dddd8","package.package.ChecklistModels.ChecklistAnswer@405ddf48","package.package.ChecklistModels.ChecklistAnswer@405de070","package.package.ChecklistModels.ChecklistAnswer@405de198","package.package.ChecklistModels.ChecklistAnswer@405de2c0","package.package.ChecklistModels.ChecklistAnswer@405de3e8","package.package.ChecklistModels.ChecklistAnswer@405de510"]

but i want something like this:

    {
 "json": 
    "values": [
        {
            "answer": "true",
            "remark":"",
            "questionId": "0"
            "checklistId": "2"
        },
        {
            "answer": "true",
            "remark":"",
            "questionId": "0"
            "checklistId": "2"
        }
    ]
}

EDIT:

this a snipped how i make the json array:

   if(cb.isChecked() || !text.getText().toString().equals("")){
                    ChecklistAnswer answer = new ChecklistAnswer(questions.get(id).id, 2, cb.isChecked(), text.getText().toString());

                    answers.add(answer);
                }
            }
            JSONArray json = new JSONArray(answers);
            String jsonString = json.toString();

it works as intended ... you just put ChecklistAnswer object into array ... not JSONObject ... ChecklistAnswer.toString() returns "xx.xx.xx.ChecklistAnswer@XXX" ... so either override ChecklistAnswer.toString method to return json string or make a function to translate ChecklistAnswer to JSOObject — Selvin
– Selvin, Commented Nov 6, 2014 at 9:51
instead answers.add(answer); use answers.add(answer.toJSONObject()); (and yeah, you have to write toJSONObject method inside ChecklistAnswer by yourself - which should be pretty simple - like putting all ChecklistAnswer`s properties into new JSONObject) — Selvin
– Selvin, Commented Nov 6, 2014 at 10:13

Nemanja Maksimovic · Accepted Answer · 2014-11-06 10:26:21Z

The problem is not the JSONArray.toString(), as @Selvin mentioned.

From JSONArray source:

/**
 * Encodes this array as a compact JSON string, such as:
 * <pre>[94043,90210]</pre>
 */
@Override public String toString() {
    try {
        JSONStringer stringer = new JSONStringer();
        writeTo(stringer);
        return stringer.toString();
    } catch (JSONException e) {
        return null;
    }
}

/**
 * Encodes this array as a human readable JSON string for debugging, such
 * as:
 * <pre>
 * [
 *     94043,
 *     90210
 * ]</pre>
 *
 * @param indentSpaces the number of spaces to indent for each level of
 *     nesting.
 */
public String toString(int indentSpaces) throws JSONException {
    JSONStringer stringer = new JSONStringer(indentSpaces);
    writeTo(stringer);
    return stringer.toString();
}

The problem is that you need to convert your ChecklistAnswer to JSON object first for your JSONArray to work properly.

Again from Javadoc:

/**
 * A dense indexed sequence of values. Values may be any mix of
 * {@link JSONObject JSONObjects}, other {@link JSONArray JSONArrays}, Strings,
 * Booleans, Integers, Longs, Doubles, {@code null} or {@link JSONObject#NULL}.
 * Values may not be {@link Double#isNaN() NaNs}, {@link Double#isInfinite()
 * infinities}, or of any type not listed here.

...

Rikkert09 · Accepted Answer · 2014-11-06 10:55:46Z

In my ChecklistAnwer class i added:

   public JSONObject toJsonObject(){
    JSONObject json = new JSONObject();

    try {
        json.put("questionId", questionId);
        json.put("checklistId", checklistId);
        json.put("answer", answer);
        json.put("remark", remark);
    } catch (JSONException e) {
        e.printStackTrace();
    }

    return json;
}

and in my other class:

JSONArray answers = new JSONArray();

ChecklistAnswer answer = new ChecklistAnswer(questions.get(id).id, 2, cb.isChecked(),         text.getText().toString());

answers.put(answer.toJsonObject());

if i filled the array:

String js = answers.toString(1);

and that returns:

[
 {
  "answer": true,
  "questionId": 1,
  "remark": "",
  "checklistId": 2
 },
 {
  "answer": false,
  "questionId": 4,
  "remark": "teesxfgtfghyfj",
  "checklistId": 2
 },
 {
  "answer": true,
  "questionId": 4,
  "remark": "",
  "checklistId": 2
 },
 {
  "answer": true,
  "questionId": 4,
  "remark": "",
  "checklistId": 2
 },
 {
  "answer": true,
  "questionId": 4,
  "remark": "",
  "checklistId": 2
 },
 {
  "answer": true,
  "questionId": 4,
  "remark": "",
  "checklistId": 2
 },
 {
  "answer": true,
  "questionId": 4,
  "remark": "",
  "checklistId": 2
 }
]

thanks to @Selvin

chiastic-security · Accepted Answer · 2014-11-06 09:54:19Z

0

You don't need to use any extra libraries. The JSONArray class has an extra .toString(int) method that does the pretty printing for you. The int parameter is the indentation factor.

JSONArray arr = ...
System.out.println(arr.toString(4));

It also works with a JSONObject.

Your bigger problem is that your JSONArray is not being constructed properly. You're supposed to add other JSONArrays and JSONObjects to it, but you're adding other objects. They are implicitly being turned into Strings. You need to convert them to JSON before putting them into your array.

answered Nov 6, 2014 at 9:54

chiastic-security

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3 Comments

Selvin Over a year ago

sorry but problem is not here ... JSONArray.toString(int) == JSONArray.toString() with default values (prolly without formating at all)

chiastic-security Over a year ago

@Selvin Looks like he had two problems! In any case, I've now covered both.

Selvin Over a year ago

i'm pretty sure that there is only one problem ... the formatting problem doesn't exists (he doesn't need formatted json - the formatted json is better for question's readability)

Nouman Ch · Accepted Answer · 2019-01-17 10:07:34Z

0

This works perfectly for me

String result = json.toString(4);

I was trying to write it into the file and this is perfect.

answered Jan 17, 2019 at 10:07

Nouman Ch

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Comments

Piotr Golinski · Accepted Answer · 2014-11-06 09:51:21Z

-1

You can use gson library : https://code.google.com/p/google-gson/

Gson gson = new Gson();
String output = gson.toJson(object);

answered Nov 6, 2014 at 9:51

Piotr Golinski

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Comments

Eldhose M Babu · Accepted Answer · 2014-11-06 09:58:00Z

-1

Try this :

JsonArray jArray = //Your Json Array;
JSONObject jObj = new JSONObject();
jObj.put("test", jArray);
String requiredString = jObj.optString("test");

answered Nov 6, 2014 at 9:58

Eldhose M Babu

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