HttpRequestExecutingMessageHandler 中的 setExpectedResponseType() 方法

Question

下面是HttpRequestExecutingMessageHandler的配置

@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;
}

下面是 REST 控制器中的 POST 方法 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);
}

下面是服务激活方法的配置：

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

我在 ResponseEntity object 的 body 中收到空值。我缺少哪个配置？

编辑 1：

当我使用setExpectedResponseType()时，控制器配置与上面相同。

@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;
}

RTPResponse object 没有包裹在 ResponseEntity 中。

我得到如下错误：

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

编辑 2：

换句话说，我应该在 HttpRequestExecutingMessageHandler 上使用什么配置来获取消息 object 以便我在消息负载中提取 body 和所有headers 到 MessageHeaders，包括状态。

我尝试使用 GenericMessage 传递给 HttpRequestExecutingMessageHandler class 的 setExpectedResponseType 方法。

但它给了我如下错误，这是可以理解的：

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?)

Answer 1

但你自己说 - setExpectedResponseType().

你真的错过了这个配置。

在这种情况下，响应实体的 body 为空：

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();
        }
    }
}

如果您不想为该选项提供 Class<?>，您可以考虑使用：

/**
 * 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) {

相反。在这种情况下，您确实可以根据 requestMessage 解析目标预期响应类型，并且还可以访问整个 BeanFactory 以进行其他一些 bean 调用。

HttpRequestExecutingMessageHandler 中的 setExpectedResponseType() 方法

setExpectedResponseType() method in HttpRequestExecutingMessageHandler

spring

spring-integration

spring-rest