FeignClient: Serialize RequestParam to JSON - spring-boot

I have a spring boot application in which I am trying to use Feign to communicate with a remote service. My #FeignClient is defined as follows:
#FeignClient(name="TEST_SERVICE", url="URL")
#Component
public interface SomeServiceClient
{
#RequestMapping(
method = RequestMethod.POST,
value = "/someService",
consumes = "application/json",
produces = "application/json"
)
SomeServiceResult getServiceResult(
#RequestParam(value = "mode") String mode,
#RequestParam(value = "payload") SomeServicePayload payload
);
}
I would like the payload object of type SomeServicePayload to be serialized into JSON. I expected this to happen automatically, but it does not. Instead, payload is serialized to its fully qualified class name.
Do I need to set a custom encoder/decoder combination for this client? How would I do this?

#FeignClient under the hood used toString() method for bulding request string. The easiest way to create proper request is to override toString() method manually:
class SomeServicePayload{
String payload;
#Override
public String toString() {
return "{\"payload\":\"" + payload + "\"}";
}
}
Or for complex objects by using ObjectMapper:
public class SomeServicePayload{
private String payload;
public String getPayload() {
return payload;
}
public void setPayload(String payload) {
this.payload = payload;
}
private ObjectMapper mapper = new ObjectMapper();
#Override
public String toString() {
try {
return mapper.writeValueAsString(this);
} catch (JsonProcessingException e) {
//...
}
return null;
}
}

Related

FeignException com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of `org.springframework.http.ResponseEntity`

Any Help please !!
I receive this error when I'm calling my endpoint which call Feign in the background :
com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of
`org.springframework.http.ResponseEntity` (no Creators, like default constructor, exist): cannot deserialize
from Object value (no delegate- or property-based Creator)
at [Source: (BufferedReader); line: 1, column: 2]
This is my endpoint inside Controller :
#RestController
#RequestMapping(Routes.URI_PREFIX)
public class CartoController {
#Autowired
private ReadCartographyApiDelegate readCartographyApiDelegate;
#GetMapping(value = "/cartographies/{uid}", produces = {MediaType.APPLICATION_JSON_VALUE})
public ResponseWrapper<ReadCartographyResponse> readCarto(HttpServletRequest request,
#PathVariable(name = "uid") String uid) {
ResponseEntity<ReadCartographyResponse> result ;
try {
result = readCartographyApiDelegate.readCartography(uid);
}catch (Exception e){
throw new TechnicalException("Error during read Carto");
}
return responseWrapperWithIdBuilder.of(result.getBody());
}
}
Interface ReadCartographyApiDelegate generated automatically by openApi from yaml file :
#javax.annotation.Generated(value = "org.openapitools.codegen.languages.SpringCodegen", date = "...")
public interface ReadCartographyApiDelegate {
default Optional<NativeWebRequest> getRequest() {
return Optional.empty();
}
default ResponseEntity<ReadCartographyResponse> readCartography(String uid) {
getRequest().ifPresent(request -> {
for (MediaType mediaType: MediaType.parseMediaTypes(request.getHeader("Accept"))) {
if (mediaType.isCompatibleWith(MediaType.valueOf("application/json"))) {
String exampleString = "null";
ApiUtil.setExampleResponse(request, "application/json", exampleString);
break;
}
}
});
return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
}
}
This my ReadCartoApiDelegateImpl which implements ReadCartographyApiDelegate interface :
#Service
public class ReadCartographyApiDelegateImpl implements ReadCartographyApiDelegate {
private EcomGtmClient ecomGtmClient;
public ReadCartographyApiDelegateImpl(EcomGtmClient ecomGtmClient) {
this.ecomGtmClient = ecomGtmClient;
}
#Override
public ResponseEntity<ReadCartographyResponse> readCartography(String uid) {
ResponseEntity<ReadCartographyResponse> response = ecomGtmClient.readCartography(uid);
return response;
}
}
This is the feign client :
#FeignClient(name = "ecomGtmSvc", url = "http://localhost/")
public interface EcomGtmClient {
#GetMapping(value = "/read-carto/{uid}")
ResponseEntity<ReadCartographyResponse> readCartography(#PathVariable("uid") String uid);
}
The problem is that ResponseEntity (spring class) class doesn't contain default constructor which is needed during creating of instance. is there Any config to resolve this issue ?
If you want access to the body or headers on feign responses, you should use the feign.Response class. ResponseEntity does not work with feign because it is not meant to. I think it is best if you just return Response from your feign client method. You should then be able to pass the body to the ResponseEntity instance in the Controller.
What is your reason to even use the response-wrapper, i can't really figure that out from your code?
Sadly I couldn't find any documentation on the Response class, but here's the link to the source on GitHub.
https://github.com/OpenFeign/feign/blob/master/core/src/main/java/feign/Response.java
My Suggestion would be
#FeignClient(name = "ecomGtmSvc", url = "http://localhost/")
public interface EcomGtmClient {
#GetMapping(value = "/read-carto/{uid}")
ReadCartographyResponse readCartography(#PathVariable("uid") String uid);
}
#RestController
#RequestMapping(Routes.URI_PREFIX)
public class CartoController {
#Autowired
private ReadCartographyApiDelegate readCartographyApiDelegate;
#GetMapping(value = "/cartographies/{uid}", produces = {MediaType.APPLICATION_JSON_VALUE})
public ResponseWrapper<ReadCartographyResponse> readCarto(HttpServletRequest request,
#PathVariable(name = "uid") String uid) {
ReadCartographyResponse result ;
try {
result = readCartographyApiDelegate.readCartography(uid);
}catch (Exception e){
throw new TechnicalException("Error during read Carto");
}
// I don't know where you get the builder from, so I assume it does something import and is needed
return responseWrapperWithIdBuilder.of(result);
}
}
Of course you'd also have to change all intermediate classes.
The Response Output was the correct Object that I have to put, cause every time I need to check the status from my feign client endpoint to do différent logic
#FeignClient(name = "ecomGtmSvc", url = "http://localhost/")
public interface EcomGtmClient {
#GetMapping(value = "/read-carto/{uid}")
ReadCartographyResponse readCartography(#PathVariable("uid") String uid);
}

Using a Wrapper Type for a DTO in Spring + Jackson

I'm trying to find a more or less elegant way to handle PATCH http operations in Spring MVC.
Basically, I'd like to perform a "dual" Jackson deserialization of a JSON document from a Request Body: one to a Map, and the other to the target POJO. Ideally, I would like to perform this in a single PartialDto<T> instance, where T is my target DTO type.
Better giving an example. Let's say I currently have this PUT mapping in a REST Controller:
#PutMapping("/resource")
public MyDto updateWhole(#RequestBody MyDto dto) {
System.out.println("PUT: updating the whole object to " + dto);
return dto;
}
My idea is to build a PartialDto type that would provide both POJO representation of the request body, as well as the Map representation, like this:
#PatchMapping("/resource")
public MyDto updatePartial(#RequestBody PartialDto<MyDto> partial) {
System.out.println("PATCH: partial update of the object to " + partial);
final MyDto dto = partial.asDto();
// Do stuff using the deserialized POJO
final Map<String, Object> map = partial.asMap();
// Do stuff as a deserialized map...
return dto;
}
I hope this will allow me to further expand the PartialDto implementation so I can perform things like this:
if (partial.hasAttribute("myAttribute")) {
final String myAttribute = dto.getMyAttribute();
// ...
}
Or even using a metamodel generator:
if (partial.hasAttribute(MyDto_.myAttribute)) {
final String myAttribute = dto.getMyAttribute();
// ...
}
So the question is simple: Jackson can easily map a JSON document to a POJO. It can also easily map a JSON document to a java Map. How can I do both at the same time in a Wrapper object such as my PartialDto?
public class PartialDto<T> {
private final Map<String, Object> map;
private final T dto;
PartialDto(Map<String, Object> map, T dto) {
this.map = map;
this.dto = dto;
}
public T asDto() {
return this.dto;
}
public Map<String, Object> asMap() {
return Collections.unmodifiableMap(this.map);
}
}
I tried to use a GenericConverter like this (that, of course, I registered in Spring MVC's FormatterRegistry):
public class PartialDtoConverter implements GenericConverter {
private final ObjectMapper objectMapper;
public PartialDtoConverter(ObjectMapper objectMapper) {
this.objectMapper = objectMapper;
}
#Override
public Set<ConvertiblePair> getConvertibleTypes() {
return Collections.singleton(new ConvertiblePair(String.class, PartialDto.class));
}
#Override
public Object convert(Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
final Class<?> targetClazz = targetType.getResolvableType().getGeneric(0).getRawClass();
final Map<String, Object> map;
try {
map = objectMapper.readValue((String) source, Map.class);
} catch (JsonProcessingException e) {
throw new RuntimeException(e); // FIXME
}
final Object dto = objectMapper.convertValue(map, targetClazz);
return new PartialDto(map, dto) ;
}
}
And this converter works well when tested directly using Spring's ConversionService:
#SpringBootTest
class ConverterTest {
#Autowired
private ConversionService conversionService;
#Test
public void testPartialUpdate() throws Exception {
final MyDto dto = new MyDto()
.setIt("It");
final PartialDto<MyDto> partialDto = (PartialDto<MyDto>) conversionService.convert(
"{ \"it\": \"Plop\" }",
new TypeDescriptor(ResolvableType.forClass(String.class), null, null),
new TypeDescriptor(ResolvableType.forClassWithGenerics(PartialDto.class, MyDto.class), null, null)
);
Assertions.assertEquals("Plop", partialDto.asDto().getIt());
Assertions.assertEquals("Plop", partialDto.asMap().get("it"));
}
}
However, it doesn't seem to work in a #RequestBody such as shown above. Reminder:
#PatchMapping("/resource")
public MyDto updatePartial(#RequestBody PartialDto<MyDto> partial) {
// ...
}
Any idea is welcome.

Spring throwing 403 exception on POST request but POSTMAN request working

I am trying to POST some data to rest api, When I send the request to API using SPRING REST I get the 403 exception.
I have tried adding user-agent header as suggested by other answers but nothing has worked for me so far. I also checked that access key when using POSTMAN and when calling the service is same. Any advice would be helpful;
The wrapper class to create the body of POST request
public class ApiRequest implements Serializable {
private static final long serialVersionUID = 3729607216939594972L;
#JsonProperty("id")
List<Integer> id;
#JsonProperty("sdate")
String sdate;
#JsonProperty("edate")
String edate;
#JsonProperty("fields")
List<String> fields;
public ApiRequest(List<Integer> id, String sdate, String edate, List<String> fields){
this.id=id;
this.sdate=sdate;
this.edate=edate;
this.fields=fields;
}
public void setEdate(String edate) {
this.edate = edate;
}
public void setSdate(String sdate){
this.sdate=sdate;
}
public void setFields(List<String> fields) {
this.fields = fields;
}
public void setId(List<Integer> id) {
this.id = id;
}
public String getEdate() {
return edate;
}
public String getSdate() {
return sdate;
}
public List<String> getFields() {
return fields;
}
public List<Integer> getId() {
return id;
}
#Override
public String toString() {
return "ApiRequest{" +
"id=" + id +
", sdate=" + sdate +
", edate=" + edate +
", fields=" + fields+
'}';
}
}
Code to call the api
private HttpHeaders getRequestHeaders() {
HttpHeaders requestHeaders = new HttpHeaders();
requestHeaders.setContentType(MediaType.APPLICATION_JSON);
requestHeaders.setAccept(Arrays.asList(MediaType.ALL));
requestHeaders.set("user-agent","Some User Agent);
requestHeaders.set("access_token", "ACCESS_TOKEN");
return requestHeaders;
}
ApiRequest request=new ApiRequest(Arrays.asList(10),DateUtil.today().toString(),DateUtil.today().plusDays(10).toString(),Arrays.asList("ALL"));
String response=post("RANDOM_URL",null,null,request,getRequestHeaders(),String.class,"");
Post super method:
public <T> T post(String baseUrl, String url, String query, Object body, HttpHeaders requestHeaders, Class<T> responseClassType, String logTag) {
// In this method body is converted to Json String and called the restExchange
If you are sure that with Postman you are getting correct results then you can enable debug logs for the underlying httpclient ( if apache http client is the underlying http library) by setting logging.level.org.apache.http=DEBUG. This will print all the request details like url, headers etc by which you can compare with what you are sending with Postman. If the client library is something different then you may need to write an interceptor to capture all the request details as explained here.

Spring Cloud OpenFeign Failed to Create Dynamic Query Parameters

Spring cloud openFeign can't create dynamic query parameters. It throws below exception because SpringMvcContract tries to find the RequestParam value attribute which doesn't exist.
java.lang.IllegalStateException: RequestParam.value() was empty on parameter 0
#RequestMapping(method = RequestMethod.GET, value = "/orders")
Pageable<Order> searchOrder2(#RequestParam CustomObject customObject);
I tried using #QueryMap instead of #RequestParam but #QueryMap does not generate query parameters.
Btw #RequestParam Map<String, Object> params method parameter works fine to generate a dynamic query parameter.
But I want to use a custom object in which the feign client can generate dynamic query parameters from the object's attributes.
From Spring Cloud OpenFeign Docs:
Spring Cloud OpenFeign provides an equivalent #SpringQueryMap annotation, which is used to annotate a POJO or Map parameter as a query parameter map
So your code should be:
#RequestMapping(method = RequestMethod.GET, value = "/orders")
Pageable<Order> searchOrder2(#SpringQueryMap #ModelAttribute CustomObject customObject);
spring-cloud-starter-feign has a open issue for supporting pojo object as request parameter. Therefore I used a request interceptor that take object from feign method and create query part of url from its fields. Thanks to #charlesvhe
public class DynamicQueryRequestInterceptor implements RequestInterceptor {
private static final Logger LOGGER = LoggerFactory.getLogger(DynamicQueryRequestInterceptor.class);
private static final String EMPTY = "";
#Autowired
private ObjectMapper objectMapper;
#Override
public void apply(RequestTemplate template) {
if ("GET".equals(template.method()) && Objects.nonNull(template.body())) {
try {
JsonNode jsonNode = objectMapper.readTree(template.body());
template.body(null);
Map<String, Collection<String>> queries = new HashMap<>();
buildQuery(jsonNode, EMPTY, queries);
template.queries(queries);
} catch (IOException e) {
LOGGER.error("IOException occurred while try to create http query");
}
}
}
private void buildQuery(JsonNode jsonNode, String path, Map<String, Collection<String>> queries) {
if (!jsonNode.isContainerNode()) {
if (jsonNode.isNull()) {
return;
}
Collection<String> values = queries.computeIfAbsent(path, k -> new ArrayList<>());
values.add(jsonNode.asText());
return;
}
if (jsonNode.isArray()) {
Iterator<JsonNode> it = jsonNode.elements();
while (it.hasNext()) {
buildQuery(it.next(), path, queries);
}
} else {
Iterator<Map.Entry<String, JsonNode>> it = jsonNode.fields();
while (it.hasNext()) {
Map.Entry<String, JsonNode> entry = it.next();
if (StringUtils.hasText(path)) {
buildQuery(entry.getValue(), path + "." + entry.getKey(), queries);
} else {
buildQuery(entry.getValue(), entry.getKey(), queries);
}
}
}
}
}

Can spring map POST parameters by a way other than #RequestBody

I am using #RestControllers with an application where all requests are POST requests ... As I learned from this post , you can't map individual post parameters to individual method arguments, rather you need to wrap all the parameters in an object and then use this object as a method parameter annotated with #RequestBody thus
#RequestMapping(value="/requestotp",method = RequestMethod.POST)
public String requestOTP( #RequestParam(value="idNumber") String idNumber , #RequestParam(value="applicationId") String applicationId) {
return customerService.requestOTP(idNumber, applicationId);
will not work with a POST request of body {"idNumber":"345","applicationId":"64536"}
MY issue is that I have A LOT of POST requests , each with only one or two parameters, It will be tedious to create all these objects just to receive the requests inside ... so is there any other way similar to the way where get request parameters (URL parameters) are handled ?
Yes there are two ways -
first - the way you are doing just you need to do is append these parameter with url, no need to give them in body.
url will be like - baseurl+/requestotp?idNumber=123&applicationId=123
#RequestMapping(value="/requestotp",method = RequestMethod.POST)
public String requestOTP( #RequestParam(value="idNumber") String idNumber , #RequestParam(value="applicationId") String applicationId) {
return customerService.requestOTP(idNumber, applicationId);
second- you can use map as follows
#RequestMapping(value="/requestotp",method = RequestMethod.POST)
public String requestOTP( #RequestBody Map<String,Object> body) {
return customerService.requestOTP(body.get("idNumber").toString(), body.get("applicationId").toString());
I have change your code please check it
DTO Class
public class DTO1 {
private String idNumber;
private String applicationId;
public String getIdNumber() {
return idNumber;
}
public void setIdNumber(String idNumber) {
this.idNumber = idNumber;
}
public String getApplicationId() {
return applicationId;
}
public void setApplicationId(String applicationId) {
this.applicationId = applicationId;
}
}
Rest Controller Method
#RequestMapping(value="/requestotp",method = RequestMethod.POST)
public String requestOTP( #RequestBody DTO1 dto){
System.out.println(dto.getApplicationId()+" (------) "+dto.getIdNumber());
return "";
}
Request Type -- application/json
{"idNumber":"345","applicationId":"64536"}
OR
#RequestMapping(value="/requestotp",method = RequestMethod.POST)
public String requestOTP( #RequestBody String dto){
System.out.println(dto);
return "";
}

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