FeignClient is changing the format of LocalDate passed to it - rest

Question

I'm have a #FeignClient in my app:
#FeignClient(name="${mongo.service.id}", url="${mongo.service.url}")
public interface MongoCustomerClaimInterface {
#GetMapping(path = "/api/customerClaim/countClaims/{businessDate}")
List<TransactionClaimStatusData> countClaimsByStatusToBusinessDate(
#PathVariable #DateTimeFormat(iso = DateTimeFormat.ISO.DATE)
LocalDate businessDate);
}
I call the feign method and passing it a formatted LocalDate variable, and printing it to the log:
LocalDate businessDate = getBusinessDate();
LocalDate formattedDate = LocalDate.parse(businessDate.toString(),
DateTimeFormatter.ISO_DATE);
log.info("formattedDate: " + formattedDate);
claimStatusDataList = mongoCustomerClaimInterface.countClaims(formattedDate);
The call generates 404 error and log:
2020-24-02 18:10:25.433 INFO DashboardServiceImpl - formattedDate: 2020-02-23
2020-24-02 18:10:25.440 DEBUG
RequestMappingHandlerMapping:
Looking up handler method for path /api/customerClaim/countClaims/2/23/20
RequestMappingHandlerMapping:
Did not find handler method for [/api/customerClaim/countClaims/2/23/20]
Although I pass a date in the format yyyy-mm-dd so it will match:
#DateTimeFormat(iso = DateTimeFormat.ISO.DATE)
Feign somehow changes the date and then no matching url is found
How can I prevent Feign from doing this and configure a uniform formatter?

Answer 1

So apparently Feign isn't working with all of SpringMvc annotations. #DateTimeFormat, as great as it is, is a SpringMvc annotation and NOT a FeignClient annotation.
I solved this by doing several things:
Created a MessageConvertersConfiguration class in my MvcConfig class.
In it, I created a LocalDate & LocalDateTime converter bean and added it to the converters list that this configurer uses when an http message arrives:
#Configuration
public class MvcConfig {
#Configuration
#EnableWebMvc
public class MessageConvertersConfiguration implements WebMvcConfigurer {
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
converters.add(new MappingJackson2HttpMessageConverter(localDateTimeConverter()));
}
#Bean
public ObjectMapper localDateTimeConverter() {
ObjectMapper mapper = new ObjectMapper();
SimpleModule localDateTimeModule = new SimpleModule();
DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("dd-MM-yyyy'T'HH:mm:ss");
localDateTimeModule.addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(dateTimeFormatter));
localDateTimeModule.addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(dateTimeFormatter));
DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");
localDateTimeModule.addDeserializer(LocalDate.class, new LocalDateDeserializer(dateFormatter));
localDateTimeModule.addSerializer(LocalDate.class, new LocalDateSerializer(dateFormatter));
mapper.registerModules(localDateTimeModule);
return mapper;
}
}
}
Created a configuration class for my feign client. In it, I instantiated a SpringMvcContract. Because Feign is created before SpringMvc, the converters we just defined won't affect feign without this contract:
#Configuration
public class FeignConfig {
#Bean
public Contract feignContract() {
return new SpringMvcContract();
}
}
Eventually, I added to configuration attribute to my FeignClient:
#FeignClient(name="${mongo.service.id}", url="${mongo.service.url}", configuration = FeignConfig.class)
public interface MongoCustomerClaimInterface {
#GetMapping(path = "/api/customerClaim/countClaimsByStatusToBusinessDate/{businessDate}")
List<TransactionClaimStatusData> countClaimsByStatusToBusinessDate(#PathVariable #DateTimeFormat(iso = DateTimeFormat.ISO.DATE) LocalDate businessDate);
}