Opensaml error receiving correct unmarshaller

Question

I am running this code at opensaml2.6

Element metadataRoot = document.getDocumentElement();

// Unmarshall
UnmarshallerFactory unmarshallerFactory = Configuration.getUnmarshallerFactory();
Unmarshaller unmarshaller = unmarshallerFactory.getUnmarshaller(metadataRoot);
if (unmarshaller == null) {
    System.out.println("Error receiving unmarshaller for this document.");
    return;
}

For the document

<?xml version="1.0" encoding="UTF-8"?><saml2:EncryptedAssertion xmlns:saml2="urn:oasis:names:tc:SAML:2.0:assertion">

Unmarshaller return a null, Can you help me to undertand how are the criterias to lookup the correct Unmarshaller and how this works at opensaml?

Answer 1

I found that there is not unmarshallers register as there is not initialization in the library:

Important piece of code:

// Initialize the library
DefaultBootstrap.bootstrap();

Answer 2

In OpenSAML3 you have to first make sure to include the opensaml-saml-impl artifact in your dependencies, since all the marshallers and unmarshallers are implemented there.

Then, as @Goblins and @Pegerto pointed out, you have to call InitializationService.initialize(). I have found this link to be useful for doing a correct initialization when using Dependency Injection https://github.com/apereo/cas/blob/master/support/cas-server-support-saml-core/src/main/java/org/apereo/cas/support/saml/OpenSamlConfigBean.java.