AWS Lambda based on Spring Cloud Function AWS 5.0.1 using Spring Boot 4 fails

[Vadym79]

I have a working example to deploy AWS Lambda using Spring Cloud Function AWS using Java 21, Spring Boot 3.4 and Spring Cloud Function 4.2.0

Now I updated it to use Java 25, Spring Boot 4.0 and Spring Cloud Function 5.0.1, see the code and it fails to start with the error message:

Field objectMapper in software.amazonaws.example.product.handler.CreateProductHandler required a bean of type 'com.fasterxml.jackson.databind.ObjectMapper' that could not be found. | Field objectMapper in software.amazonaws.example.product.handler.CreateProductHandler required a bean of type 'com.fasterxml.jackson.databind.ObjectMapper' that could not be found.
The injection point has the following annotations:

• @org.springframework.beans.factory.annotation.Autowired(required=true)
  Action:
  Consider defining a bean of type 'com.fasterxml.jackson.databind.ObjectMapper' in your configuration.

Update:

I could fix it by defining:

@Bean
public ObjectMapper objectMapper() {
    ObjectMapper mapper = new ObjectMapper();
    return mapper;
}

but I atill don't understand why I need to do it with the newer version.