CODEWITHSUNDEEP
springspring-integrationspring-rest
AbNig
AbNig

Reputation: 352

setExpectedResponseType() method in HttpRequestExecutingMessageHandler

Below is the configuration of HttpRequestExecutingMessageHandler

@ServiceActivator(inputChannel = "rtpRequestChannel")
@Bean
public MessageHandler httResponseMessageHandler(MessageChannel rtpResponseChannel) {
    HttpRequestExecutingMessageHandler handler = new HttpRequestExecutingMessageHandler(
            "http://localhost:8080/rtp");
    handler.setHttpMethod(HttpMethod.POST);
    handler.setOutputChannel(rtpResponseChannel);
    handler.setShouldTrack(true);
    handler.setStatsEnabled(true);
    return handler;
}

Below is the POST method in the REST controller class:

@RequestMapping(value = "/rtp", method = RequestMethod.POST)
@ResponseBody
public ResponseEntity<RTPResponse> persistRTP(@RequestBody RTPRequest request) {
    System.out.println("In post method " + request);
    if (request != null) {
        return new ResponseEntity<RTPResponse>(new RTPResponse("12:12:2017", "Test", null, "100", "100"), HttpStatus.OK);
    }

    return new ResponseEntity<RTPResponse>(new RTPResponse("12:12:2017", "Dummy", null, "Dummy", "Dummy"), HttpStatus.OK);
}

Below is the config of the service activator method:

@Override
@ServiceActivator(inputChannel="rtpResponseChannel")
public void makeCall(ResponseEntity<RTPResponse> message) {
    System.out.println("Message: " + message.getBody());
    System.out.println(message.getClass().getCanonicalName());
}

I am receiving null in the body of the ResponseEntity object. Which configuration am I missing?

Edit 1:

When I use the setExpectedResponseType(), with the same controller configuration as above. 

@ServiceActivator(inputChannel = "rtpRequestPostOperationRequestChannel")
@Bean
public MessageHandler httResponseMessageHandler(MessageChannel rtpRequestPostOperationResponseChannel) {
    HttpRequestExecutingMessageHandler handler = new HttpRequestExecutingMessageHandler(
            "http://localhost:8080/rtp");
    handler.setHttpMethod(HttpMethod.POST);
    handler.setOutputChannel(rtpRequestPostOperationResponseChannel);
    handler.setExpectedResponseType(RTPResponse.class);
    return handler;
}

The RTPResponse object is not wrapped in the ResponseEntity.

I get the error as below:

Caused by: org.springframework.expression.spel.SpelEvaluationException: EL1004E: Method call: Method makeCall(rtp.model.RTPResponse) cannot be found on rtp.RTPRequestServiceClient type

Edit 2:

In other words, what configuration should I use on the HttpRequestExecutingMessageHandler to get hold of the message object so that I have the extracted body in the message payload and all the headers to the MessageHeaders, including status.

I tried using GenericMessage being passed to the setExpectedResponseType method of HttpRequestExecutingMessageHandler class.

But it gave me the error as below which is understandable:

Can not construct instance of org.springframework.messaging.support.GenericMessage: no suitable constructor found, can not deserialize from Object value (missing default constructor or creator, or perhaps need to add/enable type information?)

Upvotes: 0

Views: 322

Answers (1)

Artem Bilan
Artem Bilan

Reputation: 121552

But you said yourself - setExpectedResponseType().

You really miss exactly this configuration.

In that case the body of response entity is empty:

private class ResponseEntityResponseExtractor<T> implements ResponseExtractor<ResponseEntity<T>> {

    @Nullable
    private final HttpMessageConverterExtractor<T> delegate;

    public ResponseEntityResponseExtractor(@Nullable Type responseType) {
        if (responseType != null && Void.class != responseType) {
            this.delegate = new HttpMessageConverterExtractor<>(responseType, getMessageConverters(), logger);
        }
        else {
            this.delegate = null;
        }
    }

    @Override
    public ResponseEntity<T> extractData(ClientHttpResponse response) throws IOException {
        if (this.delegate != null) {
            T body = this.delegate.extractData(response);
            return ResponseEntity.status(response.getRawStatusCode()).headers(response.getHeaders()).body(body);
        }
        else {
            return ResponseEntity.status(response.getRawStatusCode()).headers(response.getHeaders()).build();
        }
    }
}

If you don't like to provide a Class<?> for that option, you can consider to use:

/**
 * Specify the {@link Expression} to determine the type for the expected response
 * The returned value of the expression could be an instance of {@link Class} or
 * {@link String} representing a fully qualified class name.
 * @param expectedResponseTypeExpression The expected response type expression.
 * Also see {@link #setExpectedResponseType}
 */
public void setExpectedResponseTypeExpression(Expression expectedResponseTypeExpression) {

instead. In this case you really can resolve the target expected response type against a requestMessage and also get access to the whole BeanFactory for some other beans calls.

Upvotes: 2

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