On Tue, Jan 29, 2019 at 10:27 AM pscl <petercs...@gmail.com> wrote:
>
> Thanks for the feedback. Just to loop back - I ended up bypassing Mixins and
> customizing my ObjectMapper to seek out the inner Builder class via
> reflection.
>
> @Slf4j
> public class CustomObjectMapper extends ObjectMapper{
> private static final long serialVersionUID = 1L;
>
> public CustomObjectMapper() {
> this.setAnnotationIntrospector(new JacksonAnnotationIntrospector() {
> private static final long serialVersionUID = 1L;
>
> @Override
> public Class<?> findPOJOBuilder(AnnotatedClass ac) {
>
> //log.info(Class.forName(ac.getName()+"$"+ac.getRawType().getSimpleName()+"Builder");
> Class<?> innerBuilder;
> try {
> innerBuilder =
> Class.forName(ac.getName()+"$"+ac.getRawType().getSimpleName()+"Builder");
> log.info("Builder found: {}", ac.getName());
> return innerBuilder;
> } catch( ClassNotFoundException e ) {
> return super.findPOJOBuilder(ac);
> }
> }
>
> @Override
> public Value findPOJOBuilderConfig(AnnotatedClass ac) {
> if (ac.hasAnnotation(JsonPOJOBuilder.class)) {
> return super.findPOJOBuilderConfig(ac);
> }
> return new JsonPOJOBuilder.Value("build", "");
> }
> });
> }
> }
Excellent! Thank you for sharing this.
-+ Tatu +-
>
>
>
> On Thursday, January 24, 2019 at 8:45:02 PM UTC-8, Tatu Saloranta wrote:
>>
>> On Thu, Jan 24, 2019 at 8:39 PM pscl <peter...@gmail.com> wrote:
>> >
>> > Hi,
>> >
>> > Here's a question I've posted on SO - crossposting here in hope of getting
>> > some domain-expertise.
>> >
>> >
>> > I have a 3rd party Lombok builder POJO, one that I cannot modify, that I
>> > want to serialize using jackson. Notably it does not have a
>> > NoArgsConstructor.
>> >
>> > @Data
>> > @Builder
>> > public class ExternalClass {
>> > private String name;
>> > private String data;
>> > // etc.
>> > }
>> >
>> >
>> > On the surface this would appear to be simple, but it is incredibly
>> > frustrating in practice as each possible option seems to be counteracted
>> > by a different complication. In essence, I'm having trouble getting an
>> > external Lombok builder to work with a jackson mixin.
>> >
>> >
>> > Lombok produces fluent setters of the style .name(String name) while
>> > Jackson's built-in builder deserializer expects .withName(String name).
>> > Lombok documentation, and recipes elsewhere such as here suggest using
>> > @JsonDeserialize(builder=ExternalClass.ExternalClassBuilder.class) in
>> > conjunction with @JsonPOJOBuilder(withPrefix="") on a predeclared inner
>> > stub builder. But this is not possible because the Lombok class is in an
>> > external library.
>> >
>> > Applying these annotations to a mixin has no effect.
>>
>> As explained, that approach should work, I think, as long as mixins
>> are bound to targets properly (that is, value class mixin has
>> annotation pointing to target class; builder class mixin has overrides
>> for prefix name).
>> So I may be missing something here, but what? Is builder class not
>> available from sources and only materialized as part Lombok
>> processing?
>>
>> > @JsonDeserialize(ExternalClass.ExternalClassBuilder.class)
>> > public abstract class ExternalClassMixin {
>> > @JsonPOJOBuilder(withPrefix="")
>> > public static ExternalClassBuilder {
>> > }
>> > }
>> >
>> >
>> > The only approach I've found that works is to leverage the package-access
>> > AllArgsConstructor created by @Builder and populate the mixin with the
>> > following constructor
>>
>> Note that as long as annotation exists, AllArgsConstructor can even be
>> private, if that matters; Jackson can access it via reflection (unless
>> Java 11+ start blocking that or something).
>>
>> >
>> > public abstract class ExternalClassMixin {
>> > @JsonCreator public ExternalClassMixin(
>> > @JsonProperty("name") String name,
>> > @JsonProperty("data") String data,
>> > // etc.
>> > ) {}
>> > }
>> >
>> >
>> > This is obviously not desirable as it requires iterating and hard-coding
>> > every class property explicitly, making the mixin fragile to any change in
>> > the external POJO.
>> >
>> > My question is - is there a robust, maintainable way to serialize this
>> > external builder class using Jackson without modifying it, using either a
>> > mixin or maybe a full blown deserializer?
>>
>> If mixin-for-builder approach does not, maybe others have ideas.
>>
>> One interesting thing to note is that Jackson can actually override
>> settings on final properties too.
>> So as long as there are public accessors, these would be found.
>>
>> -+ Tatu +-
>
> --
> You received this message because you are subscribed to the Google Groups
> "jackson-user" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to jackson-user+unsubscr...@googlegroups.com.
> To post to this group, send email to jackson-user@googlegroups.com.
> For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups
"jackson-user" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to jackson-user+unsubscr...@googlegroups.com.
To post to this group, send email to jackson-user@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.
