You might already be familiar with the SwingLabs and SwingX projects, which provide new sets of tools and components for Swing. Richard Bair, leader of those projects, just published an excellent article about SwingX-WS.
SwingX-WS attempts to simply the use of web services (in the broad sense) by providing APIs that site on top of existing libraries. Those APIs let you, for instance, easily parse DOM documents, create and send HTTP requests in a few lines of code or even parsing HTTP form data. I really encourage you to read the SwingX-WS introductory article to see what cool new tools you can now use. I am particularly fond of the
XmlHttpRequest and the
SimpleDocument (which lets you execute and parse the result of an XPath expression very easily compared to J2SE core API.) It is also worth noting that these tools give you nice ways to perform operations in the background without blocking the GUI.
Richard's article did not talk about a very interesting component that sits in the source repository,
JXForm. This component can be compared to the form tag in XHTML pages as it sends an HTTP request which parameters are obtained from the form's children. This means that in Swing, you can simply put text fields in your GUI and JXForm will take care of creating an HTTP request for you and hand you back the result.