@Override
    protected URI getEndpointURL(final MessageContext messageContext) throws MessageEncodingException {
        try {
            return SAMLBindingSupport.getEndpointURL(messageContext);
        } catch (final BindingException e) {
            throw new MessageEncodingException("Could not obtain message endpoint URL", e);
        }
    }
{@inheritDoc}

Gets the response URL from the message context.
pac4j-saml/src/main/java/org/pac4j/saml/transport/Pac4jHTTPPostSimpleSignEncoder.java