Marker trait denoting a class that can act as a default com.twitter.finatra.http.marshalling.MessageBodyReader for the HTTP server.

This default is invoked when the com.twitter.finatra.http.internal.CallbackConverter cannot find a suitable com.twitter.finatra.http.marshalling.MessageBodyReader to convert the incoming Finagle request into the route callback input type. E.g., given a defined route in a Controller:

get("/") { request: T =>
   ...
}

The com.twitter.finatra.http.internal.CallbackConverter attempts to locate a com.twitter.finatra.http.marshalling.MessageBodyManager which can parse a Finagle request into the input type T. If one is not found, this default is invoked.

The framework binds com.twitter.finatra.http.internal.marshalling.DefaultMessageBodyReaderImpl as an overridable implementation via the com.twitter.finatra.http.modules.MessageBodyModule.

To override this implementation, provide a customized com.twitter.inject.TwitterModule by overriding com.twitter.finatra.http.HttpServer.messageBodyModule, e.g.,

class MyServer extends HttpServer {
   ...
   override val messageBodyModule = MyCustomMessageBodyModule
}

The framework default com.twitter.finatra.http.marshalling.MessageBodyReader will attempt to convert the incoming request body using the server's configured com.twitter.util.jackson.ScalaObjectMapper and is the basis for the framework's JSON Integration with Routing.

The com.twitter.finatra.http.marshalling.DefaultMessageBodyReader trait differs from the com.twitter.finatra.http.marshalling.MessageBodyReader trait in that the default is not parameterized to a specific type but instead defines a generic parse[T] function which can generate a type T from a given request.

A com.twitter.finatra.http.marshalling.MessageBodyReader is expected to only ever generate a single type T from its parse[T] implementation.