7534092ef3
This commit adds support for handling an empty request body with both HttpEntity where the body is not required and with @RequestBody where the body is required depending on the annotation's required flag. If the body is an explicit type (e.g. String, HttpEntity<String>) and the body is required an exception is raised before the method is even invoked or otherwise the body is passed in as null. If the body is declared as an async type (e.g. Mono<String>, HttpEntity<Mono<String>>) and is required, the error will flow through the async type. If not required, the async type will be passed with no values (i.e. empty). A notable exception is rx.Single which can only have one value or one error and cannot be empty. As a result currently the use of rx.Single to represent the request body in any form effectively implies the body is required.