For an alternative approach (and shameless plug!), you can have a look at my project, Dynaspring. It implements an extensible DSL for Spring which is based on Lisp rather than XML. Your example would be roughly translated to


(defun block (&key ref class url)
(if ref
(ref ref)
(bean class :properties ("url" url))))

(defmacro define-chain (name (&key xsl (parent "baseXmlService")) &body blocks)
`(defbean ,name "com.example.blocks.ChainXmlService"
:parent ,parent
:properties (,@(when xsl `("styleSheet" ,xsl))
"serviceChain" (list ,@blocks))))


and used like this:


(define-chain "chainedService" (:xsl "xsl/sample.xsl")
(block :class "com.example.blocks.HttpProxyBlock" :url "http://example.com/some/url")
(block :ref "authBlock"))