src/main/java/com/cedarsoftware/util/io/JsonWriter.java
public static String formatJson(String json, Map readingArgs, Map writingArgs)
    {
        Map args = new HashMap();
        if (readingArgs != null)
        {
            args.putAll(readingArgs);
        }
        args.put(JsonReader.USE_MAPS, true);
        Object obj = JsonReader.jsonToJava(json, args);
        args.clear();
        if (writingArgs != null)
        {
            args.putAll(writingArgs);
        }
        args.put(PRETTY_PRINT, true);
        return objectToJson(obj, args);
    }
public static String formatJson(String json, Map readingArgs, Map writingArgs)
    {
        Map args = new HashMap();
        if (readingArgs != null)
        {
            args.putAll(readingArgs);
        }
        args.put(JsonReader.USE_MAPS, true);
        Object obj = JsonReader.jsonToJava(json, args);
        args.clear();
        if (writingArgs != null)
        {
            args.putAll(writingArgs);
        }
        args.put(PRETTY_PRINT, true);
        return objectToJson(obj, args);
    }
Format the passed in JSON string in a nice, human readable format.
@param json String input JSON
@param readingArgs (optional) Map of extra arguments for parsing json.  Can be null.
@param writingArgs (optional) Map of extra arguments for writing out json.  Can be null.
@return String containing equivalent JSON, formatted nicely for human readability.