Java / Spring：将多个肥皂标题添加到getWebServiceTemplate（）。marshalSendAndReceive

Question

我是Java新手，请按照本指南https://spring.io/guides/gs/consuming-web-service/从Java Api调用Soap（.net asmx）服务。当我尝试向Soap Request添加标头时，它返回Java Null Pointer异常。如果我不提供HeaderComposedCallback，则可以调用该服务。

致电网络服务：

ValidateResponse response = (ValidateResponse) getWebServiceTemplate().marshalSendAndReceive(
                    "http://somewhere.com/service.asmx",
                    request, new HeaderComposingCallback());

实现WebServiceMessageCallback：

public class HeaderComposingCallback implements WebServiceMessageCallback {

private PrincipalIdentity prinIdentity;
private ProductIdentity prodIdentity;

public HeaderComposingCallback() {

}

@Override
public void doWithMessage(WebServiceMessage message) throws IOException, TransformerException {

    ((SoapMessage) message).setSoapAction("Validate");
    SoapHeader soapHeader = ((SoapMessage) message).getSoapHeader();

    try {

        prinIdentity.setRequestorId("value");
        ..

        prodIdentity.setAppId("value");
        ..

        JAXBContext context = JAXBContext.newInstance(PrincipalIdentity.class, ProductIdentityHeader.class);

        Marshaller marshaller = context.createMarshaller();
        marshaller.marshal(prinIdentity, soapHeader.getResult());
        marshaller.marshal(prodIdentity, soapHeader.getResult());

    } catch (JAXBException e) {
        throw new IOException("error while marshalling.");
    }
}

}