Could not extract response: no suitable HttpMessageConverter found for response type

Question

I am new with spring integration and working in spring integration http module for my project requirement. I am sending request from outbound gateway as a http client. I am trying to initiate a request to the server and server should return me the message payload with my set values. I am converting object to JSON using to send to server I am sending a request to inbound gateway present on the server side from client(HttpClientDemo) shown below. For that purpose, I am converting my object into the JSON and then converting to JSON string to object on the client side, performing some simple operation there and sending it back to the client(HttpClientDemo) but before this, I am getting exception related to HttpMessageConverter as below:

Exception in thread "main" org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class com.mycompany.MyChannel.model.FFSampleResponseHttp] and content type [text/plain;charset=UTF-8]
    at org.springframework.web.client.HttpMessageConverterExtractor.extractData(HttpMessageConverterExtractor.java:108)
    at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:784)
    at org.springframework.web.client.RestTemplate$ResponseEntityResponseExtractor.extractData(RestTemplate.java:769)
    at org.springframework.web.client.RestTemplate.doExecute(RestTemplate.java:549)
    at org.springframework.web.client.RestTemplate.execute(RestTemplate.java:517)
    at org.springframework.web.client.RestTemplate.exchange(RestTemplate.java:462)
    at org.springframework.integration.http.outbound.HttpRequestExecutingMessageHandler.handleRequestMessage(HttpRequestExecutingMessageHandler.java:421)
    at org.springframework.integration.handler.AbstractReplyProducingMessageHandler.handleMessageInternal(AbstractReplyProducingMessageHandler.java:170)
    at org.springframework.integration.handler.AbstractMessageHandler.handleMessage(AbstractMessageHandler.java:78)
    at org.springframework.integration.dispatcher.AbstractDispatcher.tryOptimizedDispatch(AbstractDispatcher.java:116)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.doDispatch(UnicastingDispatcher.java:101)
    at org.springframework.integration.dispatcher.UnicastingDispatcher.dispatch(UnicastingDispatcher.java:97)
    at org.springframework.integration.channel.AbstractSubscribablMyChannel.doSend(AbstractSubscribablMyChannel.java:77)
    at org.springframework.integration.channel.AbstractMessagMyChannel.send(AbstractMessagMyChannel.java:255)
    at org.springframework.integration.channel.AbstractMessagMyChannel.send(AbstractMessagMyChannel.java:223)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:114)
    at org.springframework.messaging.core.GenericMessagingTemplate.doSend(GenericMessagingTemplate.java:44)
    at org.springframework.messaging.core.AbstractMessageSendingTemplate.send(AbstractMessageSendingTemplate.java:93)

Please find Below related code :

Client side code: HttpClientDemo.java

public class HttpClientDemo {

    private static Logger logger = Logger.getLogger(HttpClientDemo.class);
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext("/META-INF/spring/integration/http-outbound-config.xml");
RequestGateway requestGateway = context.getBean("requestGateway", RequestGateway.class);        
        FFSampleRequestHttp FFSampleRequesthttp = new FFSampleRequestHttp();
        FFSampleRequesthttp.setMyChannelID("1");
        FFSampleRequesthttp.setMyNumber("88");
        FFSampleRequesthttp.setReferenceID("9I");
        FFSampleRequesthttp.setTemplateType(1);
        FFSampleRequesthttp.setTimestamp("today");
        FFSampleResponseHttp  reply = requestGateway.FFSampleResponsegatway(FFSampleRequesthttp);
            logger.info("Replied with: " + reply);
    }

}

My Request Gateway is as follows: RequestGateway.java

public interface RequestGateway {


    FFSampleResponseHttp FFSampleResponsegatway(FFSampleRequestHttp request);

}

http-outbound-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:int="http://www.springframework.org/schema/integration"
    xmlns:int-http="http://www.springframework.org/schema/integration/http"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration.xsd
        http://www.springframework.org/schema/integration/http http://www.springframework.org/schema/integration/http/spring-integration-http.xsd">

    <int:gateway id="requestGateway" 
                 service-interface="com.mycompany.MyChannel.Common.RequestGateway"
                 default-request-channel="requestChannel"/>

    <int:channel id="requestChannel"/>
    <int:channel id="requestChannel1"/>


<!--    com.mycompany.MyChannel.model.FFSampleResponseHttp -->

    <int-http:outbound-gateway request-channel="requestChannel1" reply-channel="replyChannel1" url="http://localhost:8080/MyChannel_prj-1.0.0.BUILD-SNAPSHOT/receiveGateway"  http-method="POST"  extract-request-payload="true" expected-response-type="com.mycompany.MyChannel.model.FFSampleResponseHttp"/>

   <int:object-to-json-transformer  input-channel="requestChannel" output-channel="requestChannel1" content-type="application/json"  result-type="STRING"/>



   <bean id="FFSampleRequestHttp" class="com.mycompany.MyChannel.model.FFSampleRequestHttp"></bean>


</beans>

Web.xml

<?xml version="1.0" encoding="ISO-8859-1" standalone="no"?>
<web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.4" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">


<servlet>
    <servlet-name>MyChannel-http</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/servlet-config.xml</param-value>
    </init-param>
    <load-on-startup>2</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>MyChannel-http</servlet-name>
    <url-pattern>/receiveGateway</url-pattern>
   </servlet-mapping>


    <welcome-file-list>
        <welcome-file>index.html</welcome-file>
    </welcome-file-list>

</web-app>

servlet-config.xml

    <int:channel id="receivMyChannel"/>

<int-http:inbound-gateway request-channel="receivMyChannel" path="/receiveGateway" supported-methods="POST"/>

    <int:service-activator input-channel="receivMyChannel">
        <bean class="com.mycompany.MyChannel.serviceImpl.FFSampleHttpImpl">
        <constructor-arg ref = "FFSampleRequestHttp"></constructor-arg>
        </bean>
        </int:service-activator>


     <bean id="FFSampleRequestHttp" class="com.mycompany.MyChannel.model.FFSampleRequestHttp"></bean>
     <bean id="FFSampleResponseHttp" class="com.mycompany.MyChannel.model.FFSampleResponseHttp"></bean>

    </beans> 



public class FFSampleHttpImpl{

    private static org.apache.log4j.Logger log = Logger
            .getLogger(FFSampleImpl.class);

    @Autowired
    FFSampleRequestHttp request;
    public FFSampleHttpImpl() {
    }

    public FFSampleHttpImpl(FFSampleRequestHttp request) {
        super();
        this.request = request;
    }





    public String issueResponseFor(String str) throws JsonParseException, JsonMappingException, IOException {

        ObjectMapper mapper = new ObjectMapper();

        FFSampleRequestHttp FFSampleRequestHttp = mapper.readValue(new String(str), FFSampleRequestHttp.class);

        FFSampleRequestHttp.setReferenceID("Hi My Number");

        String  strs = new String();

        strs = mapper.writeValueAsString(FFSampleRequestHttp);

            return strs;

        }

}

FFSampleRequestHttp.java

public class FFSampleRequestHttp {
    protected String MyNumber;  
    protected String referenceID;   
    protected String myChannelID;
    protected String timestamp;
    protected int templateType;
    public String getMyNumber() {
        return MyNumber;
    }
    public void setMyNumber(String MyNumber) {
        this.MyNumber = MyNumber;
    }
    public String getReferenceID() {
        return referenceID;
    }
    public void setReferenceID(String referenceID) {
        this.referenceID = referenceID;
    }
    public String getMyChannelID() {
        return myChannelID;
    }
    public void setMyChannelID(String myChannelID) {
        this.myChannelID = myChannelID;
    }
    public String getTimestamp() {
        return timestamp;
    }
    public void setTimestamp(String timestamp) {
        this.timestamp = timestamp;
    }
    public int getTemplateType() {
        return templateType;
    }
    public void setTemplateType(int templateType) {
        this.templateType = templateType;
    }
    }

FFSampleResponseHttp.java

public class FFSampleResponseHttp {
    protected String MyNumber;
    protected String referenceID;
    protected String myChannelID;
    protected String timestamp;
    protected int templateType;

    public String getMyNumber() {
        return MyNumber;
    }
    public void setMyNumber(String MyNumber) {
        this.MyNumber = MyNumber;
    }
    public String getReferenceID() {
        return referenceID;
    }
    public void setReferenceID(String referenceID) {
        this.referenceID = referenceID;
    }
    public String getMyChannelID() {
        return myChannelID;
    }
    public void setMyChannelID(String myChannelID) {
        this.myChannelID = myChannelID;
    }
    public String getTimestamp() {
        return timestamp;
    }
    public void setTimestamp(String timestamp) {
        this.timestamp = timestamp;
    }
    public int getTemplateType() {
        return templateType;
    }
    public void setTemplateType(int templateType) {
        this.templateType = templateType;
    }
    }

When I run the above code I get following error:

16:55:46.843 [main] DEBUG o.s.web.client.RestTemplate - Writing [{"MyNumber":"88","referenceID":"9I","myChannelID":"1","timestamp":"today","templateType":1}] as "text/plain;charset=UTF-8" using [org.springframework.http.converter.StringHttpMessageConverter@7d31a3e2]
16:55:46.988 [main] DEBUG o.s.web.client.RestTemplate - POST request for "http://localhost:8080/MyChannel_prj-1.0.0.BUILD-SNAPSHOT/receiveGateway" resulted in 200 (OK)
Exception in thread "main" org.springframework.web.client.RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class com.mycompany.MyChannel.model.FFSampleResponseHttp] and content type [text/plain;charset=UTF-8]
    at org.springframework.web.client.HttpMessageConverterExtractor. 

I have used spring integration basic sample code for reference. Please provide your input. I also tried by using the spring object mapper in the configuration files with JSON to object transformer but then also I am getting similer issues for HttpMessageConverter. Please help me with your valuable inputs/suggestion and let me know if we have any limitation with spring integration http object mapper.

---

Hi Artem, Thanks for your reply. I am still facing some challenges mentioned below. I have done the changes in my configuration files as per of your suggestion. but facing issue when using Jackson2JsonObjectMapper and need your further help. Please find below issue description.

I have done changes in my files and now files are like below: My Servlet-Config.xml file content is as below:

<int:channel id="channel1" /> 
<int:channel id="channel2" /> 
<int:channel id="channel3" /> 
<int-http:inbound-gateway request-channel="channel1" supported-methods="POST" path="/receiveGateway" /> 
- <int:service-activator input-channel="channel2"> 
- <bean class="com.myCompany.myChannel.serviceImpl.FFSampleHttpImpl"> 
<constructor-arg ref="ffSampleRequestHttp" /> 
</bean> 
</int:service-activator> 

<int:json-to-object-transformer input-channel="channel1" output-channel="channel2" type="com.myCompany.myChannel.model.FFSampleRequestHttp" object-mapper="jackson2JsonObjectMapper" /> 

<bean id="jackson2JsonObjectMapper" class="org.springframework.integration.support.json.Jackson2JsonObjectMapper" /> 
<bean id="ffSampleRequestHttp" class="com.myCompany.myChannel.model.FFSampleRequestHttp" /> 
<bean id="ffSampleResponseHttp" class="com.myCompany.myChannel.model.FFSampleResponseHttp" /> 
</beans>

Out bound file config(file which is responsible to sent message to server):

<int:gateway id="requestGateway" service-interface="com.myCompany.myChannel.Common.RequestGateway" default-request-channel="requestChannel" /> 
  <int:channel id="requestChannel" /> 
  <int:channel id="requestChannel1" /> 
  <int:object-to-json-transformer input-channel="requestChannel" output-channel="requestChannel1" content-type="application/json" /> 
  <int-http:outbound-gateway request-channel="requestChannel1" reply-channel="channel4" url="http://localhost:8080/myChannel_prj-1.0.0.BUILD-SNAPSHOT/http/receiveGateway" http-method="POST" /> 
  <bean id="FFSampleRequestHttp" class="com.myCompany.myChannel.model.FFSampleRequestHttp" /> 
  <int:json-to-object-transformer input-channel="channel4" output-channel="requestChannel" type="com.myCompany.myChannel.model.FFSampleResponseHttp" object-mapper="jackson2JsonObjectMapper" /> 
  <bean id="jackson2JsonObjectMapper" class="org.springframework.integration.support.json.Jackson2JsonObjectMapper" /> 
  </beans>

My impl class method is as below:

public  FfSampleResponseHttp issueResponseFor(FfSampleRequestHttp request) {

        FfSampleResponseHttp ffSampleResponse2 = new FfSampleResponseHttp();

        ffSampleResponse2.setCifNumber("Yappi I am in the method");
        log.info("issueResponseFor(FfSampleRequesthttp request)");

        return ffSampleResponse2;

    }

I am able to call my service method issueResponseFor present in server side from the client but when this is processing further:

Caused by: java.lang.IllegalArgumentException: 'json' argument must be an instance of: [class java.lang.String, class [B, class java.io.File, class java.net.URL, class java.io.InputStream, class java.io.Reader]
       at org.springframework.integration.support.json.Jackson2JsonObjectMapper.fromJson(Jackson2JsonObjectMapper.java:93)
       at org.springframework.integration.support.json.Jackson2JsonObjectMapper.fromJson(Jackson2JsonObjectMapper.java:44)
       at org.springframework.integration.support.json.AbstractJacksonJsonObjectMapper.fromJson(AbstractJacksonJsonObjectMapper.java:55)
       at org.springframework.integration.json.JsonToObjectTransformer.doTransform(JsonToObjectTransformer.java:78)
       at org.springframework.integration.transformer.AbstractTransformer.transform(AbstractTransformer.java:33)
       ... 54 more

I have verified while debugging that the payload body while in response is coming blank in json object in the parameter of Jackson2JsonObjectMapper.fromJson(…) after roaming through my service method successfully. I am not able to understand where am I doing the mistake. Please provide your help/input. Again let me know if I am again missing something in my config files. Thank you very much for your support.

Answer 1

As Artem Bilan said, this problem occures because MappingJackson2HttpMessageConverter supports response with application/json content-type only. If you can't change server code, but can change client code(I had such case), you can change content-type header with interceptor:

restTemplate.getInterceptors().add((request, body, execution) -> {
            ClientHttpResponse response = execution.execute(request,body);
            response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
            return response;
        });

Answer 2

Here is a simple solution

try adding this dependency

<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.8.3</version>
</dependency>

Answer 3

Since you return to the client just String and its content type == 'text/plain', there is no any chance for default converters to determine how to convert String response to the FFSampleResponseHttp object.

The simple way to fix it:

• remove expected-response-type from <int-http:outbound-gateway>
• add to the replyChannel1 <json-to-object-transformer>

Otherwise you should write your own HttpMessageConverter to convert the String to the appropriate object.

To make it work with MappingJackson2HttpMessageConverter (one of default converters) and your expected-response-type, you should send your reply with content type = 'application/json'.

If there is a need, just add <header-enricher> after your <service-activator> and before sending a reply to the <int-http:inbound-gateway>.

So, it's up to you which solution to select, but your current state doesn't work, because of inconsistency with default configuration.

UPDATE

OK. Since you changed your server to return FfSampleResponseHttp object as HTTP response, not String, just add contentType = 'application/json' header before sending the response for the HTTP and MappingJackson2HttpMessageConverter will do the stuff for you - your object will be converted to JSON and with correct contentType header.

From client side you should come back to the expected-response-type="com.mycompany.MyChannel.model.FFSampleResponseHttp" and MappingJackson2HttpMessageConverter should do the stuff for you again.

Of course you should remove <json-to-object-transformer> from you message flow after <int-http:outbound-gateway>.