Pretty-Print JSON in Java

It seems like GSON supports this, although I don't know if you want to switch from the library you are using.

From the user guide:

Gson gson = new GsonBuilder().setPrettyPrinting().create();
String jsonOutput = gson.toJson(someObject);

I used org.json built-in methods to pretty-print the data.

import org.json.JSONObject;
JSONObject json = new JSONObject(jsonString); // Convert text to object
System.out.println(json.toString(4)); // Print it with specified indentation

The order of fields in JSON is random per definition. A specific order is subject to parser implementation.

Google's GSON can do this in a nice way:

Gson gson = new GsonBuilder().setPrettyPrinting().create();
JsonParser jp = new JsonParser();
JsonElement je = jp.parse(uglyJsonString);
String prettyJsonString = gson.toJson(je);

or since it is now recommended to use the static parse method from JsonParser you can also use this instead:

Gson gson = new GsonBuilder().setPrettyPrinting().create();
JsonElement je = JsonParser.parseString​(uglyJsonString);
String prettyJsonString = gson.toJson(je);

Here is the import statement:

import com.google.gson.*;

Here is the Gradle dependency:

implementation 'com.google.code.gson:gson:2.8.7'

With Jackson (com.fasterxml.jackson.databind):

ObjectMapper mapper = new ObjectMapper();
System.out.println(mapper.writerWithDefaultPrettyPrinter().writeValueAsString(jsonObject))

From: How to enable pretty print JSON output (Jackson)

I know this is already in the answers, but I want to write it separately here because chances are, you already have Jackson as a dependency and so all you will need would be an extra line of code