spring data mongo can't pikup custom ZonedDateTime converter, why?

Question

My problem like this CodecConfigurationException when saving ZonedDateTime to MongoDB with Spring Boot >= 2.0.1.RELEASE

but I'm wrote a custom ZonedDateTime converters:

ZonedDateTimeToDateConverter

@WritingConverter
public class ZonedDateTimeToDateConverter implements Converter<ZonedDateTime, Date> {
    @Override
    public Date convert(ZonedDateTime source) {
        if (source == null) {
            return null;
        }
        return Date.from(source.toInstant());
    }
}

DateToZonedDateTimeConverter

@ReadingConverter
public class DateToZonedDateTimeConverter implements Converter<Date, ZonedDateTime> {
    @Override
    public ZonedDateTime convert(Date source) {
        if (source == null) {
            return null;
        }
        return ZonedDateTime.ofInstant(source.toInstant(), ZoneId.of("UTC"));
    }
}

and my test:

@Autowired
ReactiveMongoOperations operations;

@Test
void test() {
    ObjectId id = new ObjectId();

    Document doc = new Document();
    doc.append("_id", id);
//    doc.append("a", ZonedDateTime.now()); // works
    doc.append("zd1", new Document("f", ZonedDateTime.now())); // not working

    operations.insert(doc, "test-collection").block();

    Document found = Mono.from(operations.getCollection("test-collection")
            .find(new Document("_id", id)).first()).block();

    Assertions.assertNotNull(found);
}

if I add a ZDT instance to a first level of a document like this doc.append("a", ZonedDateTime.now()) - document saves fine. But if I place a ZDT instance to a document as a nested field (second level of nesting) I receive an exception:

org.bson.codecs.configuration.CodecConfigurationException: Can't find a codec for class java.time.ZonedDateTime.

What I'm doing wrong?

Answer 1

I solved the alike problem by adding the converters to custom converters configuration:

@Configuration
public class MongoCustomConverterConfig {

    @Bean
    public MongoCustomConversions mongoCustomConversions(){
        List<Converter<?,?>> converters = new ArrayList<>();
        converters.add(new ZoneDateTimeWriteConverter());
        converters.add(new ZonedDateTimeReadConverter());
        return new MongoCustomConversions(converters);
    }
}