Additional AMQP properties should be set

[magnusbaeck]

Description

When publishing messages we're only attaching a bare bones set of AMQP properties to the message envelope; either MessageProperties.BASIC or PERSISTENT_BASIC. Apart from the persistence property it sets the content-type property to application/octet-stream and the priority to zero.

We should set the content-type property to application/json and the timestamp property to the event's time (or possibly the current time if the event time isn't readily available).

Motivation

The content-type and timestamp properties convey useful information.

Exemplification

An application that stores messages sent on a RabbitMQ bus in a document database will be able to do the right thing without having any knowledge about Eiffel. Specifically, with an application/json content-type it'll understand that there's a JSON payload to deserialize and store, and the timestamp property allows it to timestamp the document correctly.

Possible Drawbacks

No drawbacks apart from the increased complexity of a five-line patch (plus whatever needs to be done in the tests, if anything).

[SantoshNC68]

You mean like this ??

BasicProperties msgProps = MessageProperties.BASIC;
msgProps.builder().contentType("application/json");
msgProps.builder().timestamp(new Date()); // or the event time

[magnusbaeck]

Yes, something like that.