如何从 FeignClient 端点返回 LocalDateTime？

Question

This is my FeignClient:

@FeignClient(name="${mongo.service.id}", url="${mongo.service.url}", configuration = FeignConfig.class)
public interface MongoAtmResetDataInterface {
    String requestMappingPrefix = "/api/atmResetData";

    @GetMapping(path = requestMappingPrefix + "/brinksDateTime")
    LocalDateTime fetchLastBrinksDateTime();
}

This is the call to the feign endpoint:

private String fetchLastBrinksTime() {
    return mongoAtmResetDataInterface.fetchLastBrinksDateTime()
       .toLocalDate()
       .format(DateTimeFormatter.ofPattern(DATE_FORMAT));
}

I get the following exception:

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: 
Cannot construct instance of `java.time.LocalDateTime` (no Creators, like default construct, exist): 
no String-argument constructor/factory method to deserialize from String value ('10-12-2019T14:01:39')

I do have a LocalDateTime converter in my SpringMvcConfig class & a contract in my FeignConfig class. Can anyone help- what am I missing?

Answer 1

Spring MVC using deserialize will make to an Array. But Feign call the object method with ArrayList. so you can not deserialize LocalDate.

So you can add this setting in pom.xml

<dependency>
<groupId>com.fasterxml.jackson.datatype</groupId>
<artifactId>jackson-datatype-jsr310</artifactId>

And add this to deserialize model. (com.fasterxml.jackson.datatype.jsr310.JavaTimeModule, com.fasterxml.jackson.datatype.jsr310.JSR310Module)

@Bean
public ObjectMapper serializingObjectMapper() {
    ObjectMapper objectMapper = new ObjectMapper();
    objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    objectMapper.registerModule(new JavaTimeModule());
    return objectMapper;
}

wish can help you.