Fixes: https://github.com/spring-cloud/spring-functions-catalog/issues/106 The `AbstractMessageSplitter messageSplitter` injection is too wide, and if target application has its own splitter bean, it becomes as a candidate. Since `SplitterFunctionConfiguration` expects only its own beans, rework the logic for `@Qualifier` and `Optional` to be explicit for expected beans from the `SplitterFunctionConfiguration`.