There's no direct way to use Java data types with web services, as that would undermine the cross-platform compatibility. You could transform the list into an array (which is supported), or -alternatively- embed a serialized representation (either binary of XML) if compatibility isn't important to you, although I would advise against that.
Post by:William Brogden
There is absolutely no reason to use the functionality of a List in a web service. Like Ulf said, use an array. The classes implementing List have excellent and fast toArray() methods.
In all likelyhood, a client of your web service will NOT need the List functionality, but if it does there are fast constructors that take arrays.