Description
During the implicit binding definitions we derive binding names form the function name.
For example
@Bean
Function<String, String> uppercase() {..}
... will result in two bindings: uppercase-in-0 and uppercase-out-0. We use the name of the function with suffix in/out to distinguish between the input or output binding and add an index of the input or output for cases where function take multiple arguments.
However, when explicitly defining bindings - bindings that are not backed by a function, we still treat it as an implicit binding and modify its name.
For example:
spring.cloud.stream.output-bindings=baz
... will result in baz-out-0.
This is wrong and confusing for several reasons.
First, it's pretty evident from the property name that this is an output binding and framework will treat it as such, so there is no need to add in or out suffix. The same for the index since in the context of explicit bindings you can simply define as many bindings as you want using names that you want.
Also, given that users often map binding names to a more meaningful names for cases with explicit bindings where users can already have a meaningful binding name they are forced to do such mapping again resulting in something like this which adds to the confusion:
spring.cloud.stream.output-bindings=myMeaningfulBindingName
spring.cloud.stream.function.bindings.myMeaningfulBindingName-out-0=myMeaningfulBindingName
Basically we should treat explicit binding names as they are - unchanged, This also ensures that it follows the same functionality we had with annotation-based programming model when defining explicit binings.