If you are writing a Java-backed Web Script or you are using the foundation API for things like actions or behaviors, you can use any Java API you want to make calls against any other services or web sites as you see fit. For example, you could use the Apache Commons HTTP Client.
Also be aware that the Web Script engine has out-of-the-box support for connections to RESTful services. Do some digging for the Surf remote and connector objects.
