Java JSON Creation

Question

I have the following JSON

{
        "display": {
            "icon": {
                "item": "minecraft:elytra"
            },
            "title": "Learn to Fly"
        },
        "parent": "minecraft:story/enter_end_gateway",
        "criteria": {
            "elytra": {
                "trigger": "minecraft:inventory_changed",
                "conditions": {
                    "items": [
                        {
                            "item": "minecraft:elytra",
                            "data": 1
                        }
                    ]
                }
            }
        }
    }

How would I be able to create this within Java?

Along with being able to get each element, eg the title.

Thanks!

No, I want to create this myself with different values of course (for Minecraft .JSON Achievements). I would like to know how I could go and create each element (even if you used your own example) — Chazmondo, May 14 '17 at 10:41
Use this if you want to create a Java POJO http://pojo.sodhanalibrary.com/ — SSC, May 14 '17 at 10:42
http://www.jsonschema2pojo.org/ this can help yo to create classes representing the JSON — Master Po, May 14 '17 at 10:43
Try this http://json2java.azurewebsites.net/ paste your json and generate pojo — Sreemat, May 14 '17 at 10:43
May I ask, what is pogo? I've wanted to create something as a single OOP class. — Chazmondo, May 14 '17 at 10:48
POJO for Plain Old Java Object. we can say a simple class with getters and setters for its members. — Master Po, May 14 '17 at 10:50
Possible duplicate of [Converting Java objects to JSON with Jackson](http://stackoverflow.com/questions/15786129/converting-java-objects-to-json-with-jackson) — Stefan Falk, May 14 '17 at 10:58
You were not able to google "java convert object to json" but you were able to create a question on stackoverflow? Very suspicious. — Stefan Falk, May 14 '17 at 10:59
@displayname I had already looked and could not find exactly what I was looking for — Chazmondo, May 14 '17 at 11:07

ROOT · Answer 1 · 2017-05-14T10:55:33.223

2

check this library gson from google its easy to use and have a lot of APIs to work with JSON

edited May 14 '17 at 10:55

answered May 14 '17 at 10:43

ROOT

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Thank you! As said above – Chazmondo May 14 '17 at 10:52
@Chazmondo, checkout the documentation on github: https://github.com/google/gson/blob/master/UserGuide.md#TOC-Primitives-Examples – ROOT May 14 '17 at 10:58

Andrew Tobilko · Answer 2 · 2017-05-14T11:12:45.713

The process you are asking about is called unmarshalling (parsing a serialised object in JSON/XML/other formats into an object to work with within the object-oriented context).

I would recommend having a look at Jackson. It's a popular library which is used in such the well-known frameworks like Spring (the MVC module). Having created a domain object, you could transform a jsonData into an instance of the DomainClass class like

DomainClass instance = new ObjectMapper().readValue(jsonData, DomainClass.class);

The jsonData source can be Files, InputStreams, byte arrays, Strings and so on. It's up to you to pick up the most convenient way to obtain that data.

Along with being able to get each element, eg the title.

When the instance is ready, you are free to get elements (now fields) through the accessors (the get methods).

score 1 · Accepted Answer · answered May 14 '17 at 10:57

Here is the code to build your json with org.json library in java:

import org.json.JSONArray;
import org.json.JSONObject;

public class JSONBuilderMinecraft {

    public static void main(String args[]) throws Exception{

        JSONObject mainJson = new JSONObject();



        //inner most json array
        JSONArray itemarray=new JSONArray();

        //inner most json
        JSONObject itemsJson= new JSONObject();
        itemsJson.put("item", "minecraft:elytra");
        itemsJson.put("data", 1);
        itemarray.put(itemsJson);

        JSONObject conditions = new JSONObject();
        conditions.put("items", itemarray);


        JSONObject elytra = new JSONObject();
        elytra.put("trigger", "minecraft:inventory_changed");
        elytra.put("conditions", conditions);


        mainJson.put("criteria", elytra);
        mainJson.put("parent", "minecraft:story/enter_end_gateway");

        JSONObject icon = new JSONObject();
        icon.put("item", "minecraft:elytra");

        JSONObject display = new JSONObject();
        display.put("title", "Learn to Fly");
        display.put("icon", icon);

        mainJson.put("display", display);

        System.out.println(mainJson.toString());

    }


}

that is a hard-coded solution which is difficult to maintain and read, isn't it? — Andrew Tobilko, May 14 '17 at 11:16
Yes it is, its just a point to start with. Of course you will be sending dynamic values to replace hard coded values. I would recommend gson library as well. — Tanmay Delhikar, May 14 '17 at 11:17
I've got it all sorted with dynamic values and such, what would I do to have like "criteria": { "elytra": { (and having items inside this — Chazmondo, May 14 '17 at 13:46

score 0 · Answer 4 · answered May 14 '17 at 10:46

0

instead of creating your code like this stupid idea

JSONObject jsonObject=new JSONObject();
JSONObject jsonObject2=new JSONObject();
JSONObject jsonObject3=new JSONObject();

jsonObject.put("display",jsonObject3);

you can use Gson, so simple it creates json object without wasting your time on code make a class for each new Json object and make a relations between them.

answered May 14 '17 at 10:46

Basil Battikhi

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Thank you! GSON is within the Spigot jar (by minecraft). – Chazmondo May 14 '17 at 10:51
Could you give me a couple examples with gson? – Chazmondo May 14 '17 at 10:53

score -1 · Answer 5 · answered May 14 '17 at 11:00

Try this,it works fine:

    public static void main(String[] args) throws JSONException {
        String jsonString = "{\n"
                + "        \"display\": {\n"
                + "            \"icon\": {\n"
                + "                \"item\": \"minecraft:elytra\"\n"
                + "            },\n"
                + "            \"title\": \"Learn to Fly\"\n"
                + "        },\n"
                + "        \"parent\": \"minecraft:story/enter_end_gateway\",\n"
                + "        \"criteria\": {\n"
                + "            \"elytra\": {\n"
                + "                \"trigger\": \"minecraft:inventory_changed\",\n"
                + "                \"conditions\": {\n"
                + "                    \"items\": [\n"
                + "                        {\n"
                + "                            \"item\": \"minecraft:elytra\",\n"
                + "                            \"data\": 1\n"
                + "                        }\n"
                + "                    ]\n"
                + "                }\n"
                + "            }\n"
                + "        }\n"
                + "    }";

        JSONObject object = new JSONObject(jsonString);
        JSONObject disp = object.getJSONObject("display");
        String title = disp.getString("title");

        System.out.println("title is " + title);
    }

The question was to create the json, not retrieve data after building it like your above code. — Tanmay Delhikar, May 14 '17 at 11:01
yeah exactly, I think he can use json in string format like in my code — Young Emil, May 14 '17 at 11:03

Java JSON Creation

5 Answers5