SAP Hybris adding Doctype to cXML Punchout

Question

Currently our cXML Punchout implementation (SAP hybris standard) does not print the Doctype on a response.
The the endsyste needs it:

Wed Sep 02 00:19:42 PDT 2020 (T12:prealm_1234:global\c1234:PasswordAdapter1:db2wer:C123_UI1)
    (application.cxml:ERROR) [ID1234]: CXMLDOMRequester: Unable to parse cXML response with error:
    org.xml.sax.SAXParseException: Document root element "cXML", must match DOCTYPE root "null".

I tried to do some research:
One request goes to de.hybris.platform.b2bpunchoutaddon.controllers.pages.DefaultPunchOutSetUpController.handlePunchOutSetUpRequest() and it returns a CXML Object. This Object goes through some mapper and converter, but it adds no where the Doctype.

Then I found de.hybris.platform.b2bpunchoutaddon.converter.CXMLJaxb2MessageConverter. This MessageConverter adds the Doctype to the xml header. But it never runs.
For me the spring configuration looks correct:

<alias name="cXMLJaxb2MessageConverter" alias="jaxbMessageConverter" />
<bean id="cXMLJaxb2MessageConverter" class="de.hybris.platform.b2bpunchoutaddon.converter.CXMLJaxb2MessageConverter"/>

Right now I despair on this problem. Does any of you know how to fix it?

Answer 1

This is because in your storefront extension you have the following setting of message converters:

<!-- activates annotation driven binding -->
<mvc:annotation-driven ignore-default-model-on-redirect="true" validator="validator">
    <mvc:message-converters>
        <bean class="org.springframework.http.converter.ResourceHttpMessageConverter"/>
        <bean class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter"/>
        <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" />
    </mvc:message-converters>
</mvc:annotation-driven>

so, this spring config will of course ignore the bean which your b2bpunchoutaddon creates

<alias name="cXMLJaxb2MessageConverter" alias="jaxbMessageConverter" />
<bean id="cXMLJaxb2MessageConverter" class="de.hybris.platform.b2bpunchoutaddon.converter.CXMLJaxb2MessageConverter"/>

My fix for this was to use change my storefront spring mvc config to use bean with the id="jaxbMessageConverter" instead of an inline bean:

<bean id="jaxbMessageConverter" class="org.springframework.http.converter.xml.Jaxb2RootElementHttpMessageConverter"/>

<!-- activates annotation driven binding -->
<mvc:annotation-driven ignore-default-model-on-redirect="true" validator="validator">
    <mvc:message-converters>
        <bean class="org.springframework.http.converter.ResourceHttpMessageConverter"/>
        <ref bean="jaxbMessageConverter"/>
        <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" />
    </mvc:message-converters>
</mvc:annotation-driven>

Now, we know that the alias will work and the response will contain the doctype:

    <?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE cXML SYSTEM "http://xml.cXML.org/schemas/cXML/1.2.024/cXML.dtd">
<cXML payloadID="1609762719111.6059@DESKTOP-3HR841G" timestamp="2021-01-04T14:18:39+02:00" xml:lang="en-US">
    <Response>
        <Status code="200" text="success"/>
        <PunchOutSetupResponse>
            <StartPage>
                <URL>foo.bar.bla</URL>
            </StartPage>
        </PunchOutSetupResponse>
    </Response>
</cXML>