springboot Java 14 record type causes No converter found for return value of type during json serialization

Currently, new Java 14 record types cause json serializer for spring boot http end points throw obscure errors like below.

These issues have to do with FasterXML/jackson library used by spring web/boot for json serialization, but I just wanted to mention it here for anyone interested:

No converter found for return value of type: class xxxx org.springframework.http.converter.HttpMessageNotWritableException: No converter found for return value of type: xxxx
    at org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:230)
    at org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:181)
    at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82)
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:123)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:879)
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793)
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
...
````

the reason it seems like that jackson library currently doesn't natively support java 14 types.
https://github.com/FasterXML/jackson-future-ideas/issues/46

a simple work around is to add 

@JsonAutoDetect(fieldVisibility = JsonAutoDetect.Visibility.ANY) ``` to the record type which seems to address the issue.

related FasterXML issue is https://github.com/FasterXML/jackson-future-ideas/issues/46

Comment From: wilkinsona

Thanks for letting us know. We'll upgrade to a version of Jackson with record support in due course.

Comment From: rajadilipkolli

@wilkinsona , Can we add a note in documentation that if we need to use Records, use workaround till fasterXML supports automatically.

Comment From: wilkinsona

Thanks for the suggestion, but I don't think we should do that. I don't think Spring Boot's documentation is the right place to note whether a third-party library supports certain Java features. The libraries' own documentation is a better place for it.

Comment From: ijrodrigues

You also can create a @Configuration to apply this setting to all records (avoiding annotating each one)

```import org.springframework.boot.autoconfigure.jackson.Jackson2ObjectMapperBuilderCustomizer; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration;

import static com.fasterxml.jackson.annotation.JsonAutoDetect.Visibility.ANY; import static com.fasterxml.jackson.annotation.PropertyAccessor.FIELD;

@Configuration public class JsonSerializerConfig {

@Bean
public Jackson2ObjectMapperBuilderCustomizer jacksonCustomizer() {
    return builder -> builder.visibility(FIELD, ANY);
}

}