I would like to understand the CxfPayload instantiation for the CXF to Camel direction and the purpose of org.apache.camel.component.cxf.interceptors.RemoveClassTypeInterceptor that gets inserted into the CXF interceptor chain by Camel under the payload mode. I think there is potentially some case in which some change is required.
As I see, this interceptor removes the type information from the MessagePartInfo object to affect how the payload object is instantiated later, more concretely to enforce the use of DOM that is used in Camel's CxfPayload. This interceptor is inserted after the DocLiteralInInterceptor, which is instantiating the payload object in some form. So for the very first call, it may not necessarily enforce this condition (e.g., when the type is the plain javax.xml.transform.Source, the StaxSource object gets instantiated instead). And this currently leads to a payload transfer error. For the subsequent calls, the DOM based object gets instantiated as the type information is removed in the first call and the payloads get correctly transferred. Initially, I thought I could just move RemoveClassTypeInterceptor in front of DocLiteralInInterceptor so that the type information is removed before the first instantiation takes place. But I noticed that this doesn't work because RemoveClassTypeInterceptor needs the binding operation information which is set by DocLiteralInInterceptor in the exchange context. So, to solve this situation, it seems that we need to modify CxfDefaultBinding to accept the Source in its getPayloadBodyElements method so that the DOM based payload gets created from a non-DOMSource based Source like StaxSource. With this change, I could see the payload gets correctly transferred from CXF to Camel also for the first call. As this problem only occurs when you have the Source based service method (e.g., one extending Provider<Source>), I am not sure if this issue is already known or unknown. Or I may be missing something totally. Could someone comment on this? If my description is not clear, I can provide a simple test case to illustrate this issue. Thanks for your advice. Regards, Aki
