JSON pretty-print without changing the order

Question

I use json-simple and want to have pretty-print for debugging purposes.

Here is a very relavant SO question: Pretty-Print JSON in Java

However the answer in the given thread, not only fixes the indentation but also changes the order of the items to [a ... z] using the string order of the keys.

Is there any way to fix the indentation without changing the order of the items in my JSONObject?

Example:

JSONObject myJSon = new JSONObject();
myJSon.put("zzz", 1);
myJSon.put("aaa", 1);

Gson gson = new GsonBuilder().setPrettyPrinting().create();
System.out.println( gson.toJson(myJSon) );

Output:

{
  "aaa": 1,
  "zzz": 1
}

Desired output:

{
  "zzz": 1,
  "aaa": 1
}

Edit: I'm using: org.json.simple.JSONObject

Answer 1

org.json.simple.JSONObject class extends java.util.HashMap and this is the reason why you see this order of the properties on output. setPrettyPrinting() method doesn't change the order. You can remove it from source code and nothing change. If you want to keep the order you can use java.util.LinkedHashMap instead of org.json.simple.JSONObject.

Simple example:

import java.util.LinkedHashMap;
import java.util.Map;

import com.google.gson.Gson;
import com.google.gson.GsonBuilder;

public class GsonProgram {

    public static void main(String[] args) throws Exception {
        Map<String, Integer> myJSon = new LinkedHashMap<String, Integer>();
        myJSon.put("zzz", 1);
        myJSon.put("aaa", 1);

        Gson gson = new GsonBuilder().setPrettyPrinting().create();
        System.out.println(gson.toJson(myJSon));
    }
}