Currently, the parameter outputParameterName in the @Procedure annotation is not being used to create the corresponding StoredProcedureAttributes.
This is only a problem when the @Procedure method is being created to bind the parameters by name. However, since spring-boot 2.0, if you inherit from spring-boot-parent, you have by default the compiler flag 'parameters' enabled by default, making the procedure parameters bound by name without the need of explicitly define it.
The fix in StoredProcedureAttributeSource.createFrom it's trivial. Instead of passing null to the constructor of the StoredProcedureAttributes, we can pass the actual value defined in the annotation.