Spring 集成解组

Question

我正在尝试使用 UnmarshallingTransformer 在 Spring 集成中将 java 对象解组为 xml，但收到错误消息，表明未创建有效负载。 这是我的代码：

@Bean
    public Marshaller jaxbMarshaller() {
        Jaxb2Marshaller jaxb2Marshaller = new Jaxb2Marshaller();
        jaxb2Marshaller.setClassesToBeBound(TargetedClass.class);

        return jaxb2Marshaller;
    }

@Bean
    public IntegrationFlow posting() {


        try {

            return IntegrationFlows.from(Http.inboundGateway("/foo")
                            .requestMapping(m -> m.methods(HttpMethod.POST)
                                    
                            ).errorChannel("error.input")
                    )

                    .transform(Transformers.objectToString())

                    .enrichHeaders(h -> h.headerExpression())
                    .transform(httpcallFunc())
                    .transform(new UnmarshallingTransformer((Unmarshaller) jaxbMarshaller()))

                    .get();
        } catch (Exception e) {
            System.out.println(e.getMessage());
        }
        return null;
    }

我收到此错误。

org.springframework.messaging.MessagingException: failed to create Source for payload type [com.org.model.ClassName]
org.springframework.web.client.HttpServerErrorException$InternalServerError: 500 : "<Map><timestamp>2022-03-18T11:24:26.568+00:00</timestamp><status>500</status><error>Internal Server Error</error><path>/foo</path></Map>"

当我尝试使用 UnmarshallingTransformer 时会发生这种情况。

Answer 1

UnmarshallingTransformer 默认情况下使用 DomSourceFactory。它的逻辑是这样的：

        if (this.alwaysUseSourceFactory) {
            source = this.sourceFactory.createSource(payload);
        }
        else if (payload instanceof String) {
            source = new StringSource((String) payload);
        }
        else if (payload instanceof byte[]) {
            source = new StreamSource(new ByteArrayInputStream((byte[]) payload));
        }
        else if (payload instanceof File) {
            File file = (File) payload;
            inputStream = new FileInputStream(file);
            source = new StreamSource(inputStream, file.toURI().toASCIIString());
        }
        else if (payload instanceof Document) {
            source = new DOMSource((Document) payload);
        }
        else if (payload instanceof Source) {
            source = (Source) payload;
        }
        else {
            source = this.sourceFactory.createSource(payload);
        }

由于默认选项和您的自定义类型com.org.model.ClassName，没有任何条件适用，因此它无法执行最后一个else。 DomSourceFactory 的逻辑如下：

public Source createSource(Object payload) {
    Source source = null;
    if (payload instanceof Document) {
        source = createDomSourceForDocument((Document) payload);
    }
    else if (payload instanceof String) {
        source = createDomSourceForString((String) payload);
    }
    else if (payload instanceof File) {
        source = createDomSourceForFile((File) payload);
    }
    if (source == null) {
        throw new MessagingException("failed to create Source for payload type [" +
                payload.getClass().getName() + "]");
    }
    return source;
}

这也不满足您的 com.org.model.ClassName。因此，您会在日志中看到异常等等。

我不确定您的期望是什么，但是您从 httpcallFunc() 生成的类型与 UnmarshallingTransformer 不兼容。