Integration - eXist: A NoSQL Database and Application Development Platform - page 362

its developers felt that a newer implementation written in XQuery would not only
offer better support, but also be easier to maintain.
Currently the Atom Servlet is still present in eXist, but if you are not already using it,
we would advise you not to start! An Atom API implemented in XQuery is already
under development and should hopefully be released in the near future as a replace‐
ment for the Atom Servlet.
SOAP API
Since eXist 0.8, the Axis and Admin Servlets have provided a rudimentary SOAP API
for eXist. The Axis Servlet provides retrieval and query services, while the Admin
Servlet provides services for storing and removing documents and collections. Both
Servlets are implemented with what is now quite an old version of Apache Axis, and
use the RPC-encoded form of SOAP. Around late 2006 it was widely expected that
the SOAP API written in Java would be replaced by XQuery web services imple‐
mented for the SOAP Server (see “SOAP Server” on page 362 ), but unfortunately that
work was never completed.
The use of SOAP today is often considered bloated and convoluted, and hence is
often much discouraged in favor of REST. The SOAP API in eXist was deprecated
with the release of eXist 2.0. Instead, it is recommended to use either the RESTXQ
API, the REST Server API, or the XML-RPC API. If enough interest in SOAP appears
again from the community, it is most likely that a new SOAP implementation will be
developed based on XQuery 3.0 annotations influenced by JAX-WS , in a similar fash‐
ion to RESTXQ (see “RESTXQ” on page 353 ).
For Microsoft .NET developers there is still something of an
advantage in using the SOAP API because of the wizard-driven
web service client proxy generation tools offered by Microsoft Vis‐
ual Studio. While we would suggest using the REST API if you are
investing in eXist-db in the medium to long term, the SOAP API
can be the easiest and fastest route to a working application
for .NET developers in the short term.
SOAP Server
The SOAP Server was developed in 2006 as a mechanism for transparently wiring
SOAP requests and responses to XQuery functions. The SOAP Server automatically
generates WSDL (Web Services Description Language) for an XQuery library module
and marshals and demarshals the function parameters and results from and into a
SOAP envelope. The SOAP Server attempted to deliver both RPC and Document Lit‐
eral forms of SOAP web services transparently.