JSON Formatter for Java

import com.fasterxml.jackson.databind.ObjectMapper;

ObjectMapper mapper = new ObjectMapper();

// writerWithDefaultPrettyPrinter() adds indentation
String formatted = mapper
    .writerWithDefaultPrettyPrinter()
    .writeValueAsString(data);

System.out.println(formatted);

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

Gson gson = new GsonBuilder()
    .setPrettyPrinting()
    .create();

String formatted = gson.toJson(data);
System.out.println(formatted);

ObjectMapper mapper = new ObjectMapper();

Object json = mapper.readValue(rawJsonString, Object.class);
String pretty = mapper
    .writerWithDefaultPrettyPrinter()
    .writeValueAsString(json);