这是一个spring集成（基于spring boot）项目，我配置了spring集成应用程序如下：，
配置xml:

<int:channel id="httpChannel"/>

 <int-http:inbound-gateway  supported-methods="GET,POST" request-channel="httpChannel" reply-channel="outputChannel" path="/"
  message-converters="converter" 
 /> 
 <bean id="converter" class="in.tc.springintegrationdemo.CustomConverter" />

  <int:transformer ref="customTransformer" input-channel="httpChannel" output-channel="outputChannel" />  

  <bean id="customTransformer" class="in.tc.springintegrationdemo.MultipartTransformer" />  

   <bean class="in.tc.springintegrationdemo.MessageUpdateBean" id="printMessage"/> 
<int:service-activator ref="printMessage" method="print"  input-channel="outputChannel">
</int:service-activator>

自定义转换器定义如下

public class CustomConverter implements HttpMessageConverter<MultiValueMap<String,?>> {

    @Override
    public boolean canRead(Class<?> clazz, MediaType mediaType) {
      ...
    }

    @Override
    public boolean canWrite(Class<?> clazz, MediaType mediaType) {
        return false;
    }

    @Override
    public List<MediaType> getSupportedMediaTypes() {
        return Collections.singletonList(MediaType.MULTIPART_FORM_DATA);
    }

    @Override
    public MultiValueMap<String,?> read(Class<? extends MultiValueMap<String,?>> clazz, HttpInputMessage inputMessage)
            throws IOException, HttpMessageNotReadableException {
         MultiValueMap<String, ?> result = new LinkedMultiValueMap<>();
         String str = "";
        MediaType contentType = inputMessage.getHeaders().getContentType();
                BufferedReader bufferedReader = new BufferedReader(
                        new InputStreamReader(inputMessage.getBody(), contentType.getCharset()));
                while((str=bufferedReader.readLine())!=null) {

                    //code to retrieve multipart data
                }
        return result;
    }

    @Override
    public void write(MultiValueMap<String,?> t, MediaType contentType, HttpOutputMessage outputMessage)
            throws IOException, HttpMessageNotWritableException {
        throw new UnsupportedOperationException();
    }

对于多部分/表单数据，我总是在customconverter类中得到一个空的负载。
我还尝试添加一个多部分解析器，如下所示

<bean id="multipartResolver"
    class="org.springframework.web.multipart.commons.CommonsMultipartResolver"/> but it has the same result.

我在stackoverflow-spring集成dsl-http入站网关使用多部分/表单数据时也遇到了类似的问题。但对我来说没用。
多部分/表单数据负载

POST / HTTP/1.1
User-Agent: PostmanRuntime/7.26.8
Accept: */*
Postman-Token: d24d89ef-c52b-492a-96b9-6ef6807e8d1a
Host: localhost:9090
Accept-Encoding: gzip, deflate, br
Connection: keep-alive
Content-Type: multipart/form-data; boundary=--------------------------865732735860935509694157
Content-Length: 217

----------------------------865732735860935509694157
Content-Disposition: form-data; name=""; filename="testfile.txt"
Content-Type: text/plain

testcontent
----------------------------865732735860935509694157--

谢谢期待。