@SpringBootApplication above has a function that can be
decorated at runtime by Spring Cloud Function to be an HTTP endpoint,
or a Stream processor, for instance with RabbitMQ, Apache Kafka or
@Beans can be
Supplier (all from
java.util), and their parametric types can be String or POJO.
Functions can also be of
Flux<Pojo> and Spring
Cloud Function takes care of converting the data to and from the
desired types, as long as it comes in as plain text or (in the case of
the POJO) JSON. There is also support for
Message<Pojo> where the
message headers are copied from the incoming event, depending on the
adapter. The web adapter also supports conversion from form-encoded
data to a
Map, and if you are using the function with Spring Cloud
Stream then all the conversion and coercion features for message
payloads will be applicable as well.
Functions can be grouped together in a single application, or deployed one-per-jar. It’s up to the developer to choose. An app with multiple functions can be deployed multiple times in different "personalities", exposing different functions over different physical transports.