Why Feign Fails with LocalDate/LocalDateTime and How to Fix It

Problem

When a Spring Cloud Feign client sends or receives a request that contains Java 8 date‑time types ( LocalDate, LocalTime, LocalDateTime), Jackson may fail to deserialize the value and throw a HttpMessageNotReadableException.

Typical error log

2018-03-13 09:22:58,445 WARN  [http-nio-9988-exec-3] org.springframework.web.servlet.support.DefaultHandlerExceptionResolver - Failed to read HTTP message: org.springframework.http.converter.HttpMessageNotReadableException: JSON parse error: Can not construct instance of java.time.LocalDate: no suitable constructor found, can not deserialize from Object value (missing default constructor or creator), or perhaps need to add/enable type information?; nested exception is com.fasterxml.jackson.databind.JsonMappingException: Can not construct instance of java.time.LocalDate: no suitable constructor found, can not deserialize from Object value (missing default constructor or creator), or perhaps need to add/enable type information?) at [Source: java.io.PushbackInputStream@67064c65; line: 1, column: 63] (through reference chain: java.util.ArrayList[0]->com.didispace.UserDto["birthday"])

Root cause

Spring MVC’s default Jackson configuration serializes LocalDate as an array of numbers (e.g., [2023,4,10]). Feign, however, expects the JSON field to be a plain ISO‑8601 string (e.g., "2023-04-10"). The mismatch causes Jackson to treat the incoming value as an ArrayList and fail to construct a LocalDate instance.

Solution

Add the Java 8 date‑time module

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

If the project uses Spring Boot’s parent POM, the version is managed automatically.

Register the module and disable timestamp output

@Bean
public ObjectMapper objectMapper() {
    ObjectMapper mapper = new ObjectMapper();
    // Prevent serialization as numeric timestamps
    mapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);
    // Register support for Java 8 date/time types
    mapper.registerModule(new JavaTimeModule());
    return mapper;
}

This configuration makes Jackson write dates in ISO‑8601 format and correctly deserialize them back to LocalDate , LocalTime , and LocalDateTime .

Verify the fix After adding the dependency and the ObjectMapper bean, the endpoint returns a JSON payload such as: {"userName":"alice","birthday":"2023-04-10"} Feign now maps the birthday field to a LocalDate without errors.

Minimal reproducible example

@SpringBootApplication
public class Application {
    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }
}

@RestController
class HelloController {
    @PostMapping("/user")
    public UserDto echo(@RequestBody UserDto dto) {
        return dto;
    }
}

@Data
@NoArgsConstructor
@AllArgsConstructor
static class UserDto {
    private String userName;
    private LocalDate birthday;
}

With the jackson-datatype-jsr310 dependency and the custom ObjectMapper bean shown above, the birthday field is serialized as an ISO‑8601 string and deserialized correctly by both Spring MVC and Feign clients.