Making a Json Array of Json Objects Using Gson

Question

I am trying to construct a Json Array which contains Json Objects. I remember doing this some time ago with org.json but now i am having trouble doing it with gson. The structure for my json array should be like:

[
    {
        "colour": "abc",
        "time": "xyz
    },
    {
        "colour": "abc",
        "time": "xyz"
    }
]

i am reading the length and area values from a database by looping through json format files that i got using .get() thanks to jersey. I have managed to form internal json objects {"colour": "xyz", "time": "abc" }. What i have done is stored these objects in an array of json objects. Then i have tried using gson.toJson method to form the array containing these objects. Although doing so gives me something close to my requirement but i want it to be more compact. Here is the json array that i managed to generate.

 [
{
    "members": {
        "colour": {
            "value": "xyz"
        },
        "time": {
            "value": "abc"
        }
    }
},
{
    "members": {
        "colour": {
            "value": "abc"
        },
        "time": {
                "value": "xyz"
            }
        }
    }
]

I want to get rid of the redundant "members" and "value" keywords.

My code for this json array is

JsonObject[] innerObjJson = new JsonObject[hits];

for (int i=0;i<hits;i++){
        String colour  = jsonVariable.getAsJsonObject().get(i).getAsJsonObject().get("colour").toString();
        String time  = jsonVariable.getAsJsonObject().get(i).getAsJsonObject().get("time").toString();


        colour = colour.replaceAll("\"" ,"");
        time = colour.replaceAll("\"" ,"");


        InnerJsonStructure innerObj = new InnerJsonStructure(colour,time);

        Gson gson = new Gson();
        String innerObjString = gson.toJson(innerObj);
        JsonParser parserNew = new JsonParser();
        innerObjJson[i] = (JsonObject)parserNew.parse(innerObjString);
}


        Gson gson1 = new Gson();
        String finalJsonArr = gson1.toJson(innerObjJson);
        System.out.println(finalJsonArr);

The InnerJsonStructure is

public class InnerJsonStructure {
    public String colour;
    public String time;



    InnerJsonStructure(String Color, String Time){
        this.colour = Color;
        this.time = Time;


    }
}

Any help?

the first json in my question, that is what i expect.. where i just have an array with objects { "colour": "abc", "time": "xyz" } — Arsalan Ahmed
– Arsalan Ahmed, Commented Aug 28, 2015 at 15:30

Carlos Laspina · Accepted Answer · 2015-08-28 15:44:13Z

1

You need to define an object data base, to put together a list of the object, something like this:

public class DataObject {

    private String colour = "";
    private String time = "";

    public String getColour() {
        return colour;
    }

    public void setColour(String colour) {
        this.colour = colour;
    }

    public String getTime() {
        return time;
    }

    public void setTime(String time) {
        this.time = time;
    }

}

import java.io.FileWriter;
import java.io.IOException;
import com.google.gson.Gson;
import java.util.ArrayList;
import java.util.List;

public class GsonExample {

    public static void main(String[] args) {

        DataObject obj1 = new DataObject();
        obj1.setColour("abc");
        obj1.setTime("12:00");

        DataObject obj2 = new DataObject();
        obj1.setColour("def");
        obj1.setTime("24:00");

        List<DataObject> lista = new ArrayList<>();
        lista.add(obj1);
        lista.add(obj2);

        Gson gson = new Gson();
        String json = gson.toJson(lista);

        try {
            FileWriter writer = new FileWriter("c:\\file.json");
            writer.write(json);
            writer.close();

        } catch (IOException e) {
            e.printStackTrace();
        }

        System.out.println(json);

    }
}

When the code is executed, the console output is as follows:

[{"colour":"abc","time":"12:00"},{"colour":"def","time":"24:00"}]

answered Aug 28, 2015 at 15:44

Carlos Laspina

2,3014 gold badges29 silver badges44 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Arsalan Ahmed Over a year ago

thanks. i saw my mistake immediately. I was passing an array of objects to gson, but i needed to pass a list of objects to it. Now it works perfectly.

Collectives™ on Stack Overflow

Making a Json Array of Json Objects Using Gson

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related