javaspring-bootspring-cloud-feignfeignopenfeign

Reputation: 1017

Jackson with Feign can't deserialized Spring's org.springframework.data.domain.Sort

The problem: A feign client, making an API call to a Spring boot Rest API that returns a Page<T> can't deserialize the sort property of that page.

Spring Boot: 2.3.3.Release
Spring Cloud Feign: 2.2.5.RELEASE

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of org.springframework.data.domain.Sort (no Creators, like default constructor, exist): cannot deserialize from Object value (no delegate- or property-based Creator) at [Source: (BufferedReader); line: 1, column: 238] (through reference chain: org.springframework.cloud.openfeign.support.PageJacksonModule$SimplePageImpl["sort"])

Not sure why the registered PageJacksonModule doesn't seem to support that.

Given a manually configured Feign client:

public class TelematicsConfig {

  private String host;

  ObjectMapper provideObjectMapper() {
    return new ObjectMapper()
        .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
        .setPropertyNamingStrategy(SnakeCaseStrategy.SNAKE_CASE)
        .registerModule(new PageJacksonModule());
  }

  @Bean
  TelematicsClient provideTelematicsClient() {
    return Feign.builder()
        .client(new OkHttpClient())
        .encoder(new JacksonEncoder(provideObjectMapper()))
        .decoder(new JacksonDecoder(provideObjectMapper()))
        .logger(new Slf4jLogger(TelematicsClient.class))
        .logLevel(Logger.Level.FULL)
        .target(TelematicsClient.class, host);
  }

}

The client itself:

public interface TelematicsClient {

  @RequestLine("GET /api/v1/telematics/devices")
  Page<TelematicsDevice> getDevices();

}

When invoking this I get:

2020-09-16 12:38:49.707 ERROR 96244 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet]    : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is feign.FeignException: Cannot construct instance of `org.springframework.data.domain.Sort` (no Creators, like default constructor, exist): cannot deserialize from Object value (no delegate- or property-based Creator)
 at [Source: (BufferedReader); line: 1, column: 238] (through reference chain: org.springframework.cloud.openfeign.support.PageJacksonModule$SimplePageImpl["sort"]) reading GET http://localhost:8081/api/v1/telematics/devices] with root cause

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `org.springframework.data.domain.Sort` (no Creators, like default constructor, exist): cannot deserialize from Object value (no delegate- or property-based Creator)
 at [Source: (BufferedReader); line: 1, column: 238] (through reference chain: org.springframework.cloud.openfeign.support.PageJacksonModule$SimplePageImpl["sort"])
    at com.fasterxml.jackson.databind.exc.InvalidDefinitionException.from(InvalidDefinitionException.java:67)
    at com.fasterxml.jackson.databind.DeserializationContext.reportBadDefinition(DeserializationContext.java:1611)
    at com.fasterxml.jackson.databind.DatabindContext.reportBadDefinition(DatabindContext.java:400)
    at com.fasterxml.jackson.databind.DeserializationContext.handleMissingInstantiator(DeserializationContext.java:1077)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromObjectUsingNonDefault(BeanDeserializerBase.java:1320)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:331)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:164)
    at com.fasterxml.jackson.databind.deser.SettableBeanProperty.deserialize(SettableBeanProperty.java:542)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeWithErrorWrapping(BeanDeserializer.java:535)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeUsingPropertyBased(BeanDeserializer.java:419)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.deserializeFromObjectUsingNonDefault(BeanDeserializerBase.java:1310)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:331)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:164)
    at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:4482)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:3463)
    at feign.jackson.JacksonDecoder.decode(JacksonDecoder.java:61)

Any insights into why this isn't working would be greatly appreciated.

Edit: The following class seems to hint at support for sorting, no?

https://github.com/spring-cloud/spring-cloud-openfeign/blob/master/spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/support/PageJacksonModule.java#L69

Upvotes: 5

Answers (5)

Muhammed_G

Reputation: 488

My solution to solve Sort and Page issues with feign client is like the bellow steps:

Create class of type CustomPageDeserializer<T>:

import com.fasterxml.jackson.core.JsonParser; 
import com.fasterxml.jackson.databind.DeserializationContext; 
import com.fasterxml.jackson.databind.JsonDeserializer; 
import com.fasterxml.jackson.databind.JsonNode; 
import com.fasterxml.jackson.databind.ObjectMapper; 
import org.springframework.data.domain.PageImpl; 
import org.springframework.data.domain.PageRequest;
import java.io.IOException; 
import java.util.List;

public class CustomPageDeserializer<T> extends JsonDeserializer<PageImpl<T>> {

    private final Class<T> contentClass;

    public CustomPageDeserializer(Class<T> contentClass) {
        this.contentClass = contentClass;
    }

    @Override
    public PageImpl<T> deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
        ObjectMapper mapper = (ObjectMapper) jsonParser.getCodec();
        JsonNode root = mapper.readTree(jsonParser);
        JsonNode content = root.get("content");
        List<T> contentList = mapper.readValue(content.traverse(), mapper.getTypeFactory().constructCollectionType(List.class, contentClass));
        int totalElements = root.get("totalElements").asInt();
        int totalPages = root.get("totalPages").asInt();
        int number = root.get("number").asInt();

        int pageSize = contentList.isEmpty() ? 1 : contentList.size();
        return new PageImpl<>(contentList, PageRequest.of(number, pageSize), totalElements);
    } }

Create class CustomPageModule:

import com.fasterxml.jackson.databind.module.SimpleModule; 
import org.springframework.data.domain.PageImpl;

public class CustomPageModule  extends SimpleModule {
    public CustomPageModule(Class<?> contentClass) {
        addDeserializer(PageImpl.class, new CustomPageDeserializer<>(contentClass));
    } }

Create class MyFeignClientConfiguration:

import com.fasterxml.jackson.databind.ObjectMapper; 
import feign.codec.Decoder; 
import feign.optionals.OptionalDecoder; 
import org.springframework.boot.autoconfigure.http.HttpMessageConverters;
import org.springframework.cloud.openfeign.support.ResponseEntityDecoder;
import org.springframework.cloud.openfeign.support.SpringDecoder;
import org.springframework.context.annotation.Bean; 
import org.springframework.context.annotation.Configuration; 
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;

@Configuration 
public class MyFeignClientConfiguration {
    @Bean
    public Decoder feignDecoder() {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.registerModule(new CustomPageModule(MyEntity.class));
        return new OptionalDecoder(new ResponseEntityDecoder(new SpringDecoder(() -> new HttpMessageConverters(new
MappingJackson2HttpMessageConverter(objectMapper)))));
    } }

Create class MyFeignClient:

import org.springframework.cloud.openfeign.FeignClient; 
import org.springframework.http.ResponseEntity; 
import org.springframework.web.bind.annotation.GetMapping; 
import java.util.List;

@FeignClient(name = "myFeignClient", url =
"${my.service.feign.url}", configuration =
MyFeignClientConfiguration.class) 
public interface MyFeignClient {

    @GetMapping("/api/action/products")
    ResponseEntity<List<String>> getAvailableProducts(); }

Upvotes: 0

TheJeff

Reputation: 4121

You can get these modules by adding the openfeign-core dependency:

implementation "org.springframework.cloud:spring-cloud-openfeign-core"

But this doesn't work in Spring Boot 3 for the SortJacksonModule anymore.

For example:

Code (Kotlin)

private val mapper = jacksonObjectMapper().registerModules(
    PageJacksonModule(),
    SortJacksonModule(),
    JavaTimeModule(),
)

Config:

Throws this exception:

java.lang.NoClassDefFoundError: feign/codec/EncodeException at org.springframework.cloud.openfeign.support.SortJacksonModule.setupModule(SortJacksonModule.java:47)

Resolution

The OpenFeign spring team are waiting for votes in order to spend the time to fix this issue. Make sure to vote on the issue here:

https://github.com/spring-cloud/spring-cloud-openfeign/issues/675

Upvotes: 1

Mohamed.Abdo

Reputation: 2200

try to add :

    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-openfeign-core</artifactId>
        <version>3.1.3</version>
        <scope>compile</scope>
    </dependency>

Upvotes: 0

Ilya Serbis

Reputation: 22333

If you use autoconfigured Feign client you can follow Spring Cloud OpenFeign docs by turning on corresponding configuration property:

You may consider enabling Jackson Modules for the support org.springframework.data.domain.Page and org.springframework.data.domain.Sort decoding.
feign.autoconfiguration.jackson.enabled=true

Upvotes: 18

Erik

Reputation: 1017

Found the answer.

https://github.com/spring-cloud/spring-cloud-openfeign/blob/master/spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/support/SortJacksonModule.java

    return new ObjectMapper()
        .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false)
        .setPropertyNamingStrategy(SnakeCaseStrategy.SNAKE_CASE)
        .registerModule(new PageJacksonModule())
        .registerModule(new SortJacksonModule()); // <-- This.  duh.

Upvotes: 11

Jackson with Feign can&#39;t deserialized Spring&#39;s org.springframework.data.domain.Sort