yah they should've done something like:

    send(JSONSerialization.with(StringSerializer.class, DateTimeSerializer.class).serialize(JSONObjectFactory.put(PairFactory.of(String.class, String.class).getInstance("author", "system"), PairFactory.of(String.class, String.class).getInstance("message", "Only json is allowed"), PairFactory.of(String.class, DateTime.class).getInstance("time", new Date())).getInstance()))

no, it's just json4s dsl for constructing json. If you wanted, you could've used constructors yourself:

    send(pretty(render(JObject(List(JField("author", JString("system")), JField("message", JString("Only json allowed")), JField("time", JString(new DateTime().getTime().toString()))))

usually scala libraries come with an easy to read/write DSL version of the API along with a more verbose java-style API shown above. Many libraries don't document with a plenty of examples. But, it really takes 10 minutes to learn DSL version in many cases. And, it gives you wings. There are plenty of benefits of DSL. You can research online about them.