create a json data object in java

Question

Can someone provide me java code to create a json object as shown below

 {"main":[
       ["one","two","three","four","five"],
       ["one","two","three","four","five"],
       ["one","two","three","four","five"],
       ["one","two","three","four","five"],
       ["one","two","three","four","five"]
]}

I have tried something like

        Gson gson = new Gson();
        JsonArray array = new JsonArray();

        array.add(new JsonPrimitive("One"));
        array.add(new JsonPrimitive("two"));
        array.add(new JsonPrimitive("three"));
        array.add(new JsonPrimitive("four"));
        array.add(new JsonPrimitive("five"));

        JsonObject jsonObject = new JsonObject();
        jsonObject.add("main", array);

I am getting the result like below even when I am looping

{"main":["one","two","three","four","five"]}

like a single object. But I am expecting the result like

{"main":[
       ["one","two","three","four","five"],
       ["one","two","three","four","five"],
       ["one","two","three","four","five"],
       ["one","two","three","four","five"],
       ["one","two","three","four","five"]
]}

Many thanks in advance.

kedar kamthe · Accepted Answer · 2017-05-18 05:11:55Z

2

try this code to create json

Gson gson = new Gson();
JsonArray array = new JsonArray();
JsonArray child = new JsonArray();

child.add(new JsonPrimitive("One"));
child.add(new JsonPrimitive("two"));
child.add(new JsonPrimitive("three"));
child.add(new JsonPrimitive("four"));
child.add(new JsonPrimitive("five"));

for(int i=0;i<5;i++)
array.add(child);


JsonObject jsonObject = new JsonObject();
jsonObject.add("main", array);

System.out.println(jsonObject);

answered May 18, 2017 at 5:11

kedar kamthe

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Comments

mattmess1221 · Accepted Answer · 2017-05-18 05:26:56Z

Assuming you're using Gson, this isn't the way it was designed to be used. Though this way is supported, it is not suggested, as you could use any json library to do this (SimpleJson).

Instead, Gson is able to directly serialize java objects we are familiar with, so you should represent your json object as a java object. JsonObject maps to a Map. JsonArray maps to List or an array. JsonPrimitives are mapped to their respective java primitive types (boolean, double, string, null)

// generate the object
Map<List<List<String>>> object = new HashMap<>();
List<List<String>> main = new ArrayList<>();
List<String> counts = Arrays.asList("one", "two", "three", "four", "five");
for (int i = 0; i < 5; i++) {
    main.add(counts);
}
object.put("main", main);

// serialize it
String json = new Gson().toJson(object);

// deserializing it requires a typetoken or separate class representing the map object.
Map<List<List<String>>> desObj = new Gson().fromJson(json, new TypeToken<Map<List<List<String>>>>(){}.getType());

dat3450 · Accepted Answer · 2017-05-18 04:56:30Z

0

It appears "main" contains an array of arrays, so all you would have to do is add your array five times to another new array (e.g. call it mainArray) and then add mainArray to your jsonObject:

Create a new empty array: mainArray
Add array five times to mainArray
Add mainArray to jsonObject

answered May 18, 2017 at 4:56

dat3450

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Comments

user671150 · Accepted Answer · 2017-05-18 05:06:41Z

You can try to convert the string representing your json data to JsonObject:

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;


public class JsonQuestion {

    public static void main(String[] args) {

        String myJSON = "{\"main\":[\n"
                + "   [\"one\",\"two\",\"three\",\"four\",\"five\"],\n"
                + "   [\"one\",\"two\",\"three\",\"four\",\"five\"],\n"
                + "   [\"one\",\"two\",\"three\",\"four\",\"five\"],\n"
                + "   [\"one\",\"two\",\"three\",\"four\",\"five\"],\n"
                + "   [\"one\",\"two\",\"three\",\"four\",\"five\"]\n"
                + "]}";

        JsonParser jsonParser = new JsonParser();
        JsonObject jsonObject = (JsonObject) jsonParser.parse(myJSON);
        System.out.println("jsonObject: " + jsonObject.toString());

    }
}

Jin Tim · Accepted Answer · 2017-05-18 05:14:53Z

0

    Gson gson = new Gson();
    JsonArray array = new JsonArray();

    array.add(new JsonPrimitive("One"));
    array.add(new JsonPrimitive("two"));
    array.add(new JsonPrimitive("three"));
    array.add(new JsonPrimitive("four"));
    array.add(new JsonPrimitive("five"));

    JsonObject jsonObject = new JsonObject();

    JsonArray marray = new JsonArray();
    marray.add(array);
    marray.add(array);
    marray.add(array);
    marray.add(array);
    marray.add(array);
    jsonObject.add("main", marray);

answered May 18, 2017 at 5:14

Jin Tim

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Comments

Chetan Joshi · Accepted Answer · 2017-05-18 05:23:41Z

0

You can use below method to make json :

 private void createJsonData(){
        final String[] units = {"One","Two","Three","Four",
                "Five"};
        try {
        JSONObject jsonObject = new JSONObject();
        JSONArray  jsonArray = new JSONArray();

            JSONArray  jsonArray1 = new JSONArray();
            for (int j = 0; j < 5 ; j++) {
                jsonArray1.put(units[j])
            }
            jsonArray.put(jsonArray);

            jsonObject.put("main",jsonArray);
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }

answered May 18, 2017 at 5:23

Chetan Joshi

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Comments

Chakresh Tiwari · Accepted Answer · 2020-03-24 10:28:50Z

0

Use this method

public static void newjson() {
        JSONObject json =new JSONObject();
        List<List<String>> listoflist  = new ArrayList<List<String>>();
        List<String> list=new ArrayList<String>();
        list.add("one");
        list.add("one");
        list.add("one");


        listoflist.add(list);
        listoflist.add(list);
        try {
            json.put("main",listoflist);
        } catch (JSONException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println(json);
    }

answered Mar 24, 2020 at 10:28

Chakresh Tiwari

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