Subjective opinion:
If you don't know such basic things such as placing java files into right directories, perhaps, you should first try a few much simpler examples, than creating a web
service.
In Netbeans, you can create a Java project, than add Java classes by doing
File -> New... -> Java -> Java Class
To learn how to use Netbeans, visit:
http://netbeans.org/kb/
Especially "NetBeans IDE Java Quick Start Tutorial" might be helpful to start.
Furthermore, you don't run Java webapps with some kind of XAMP,
but with Java web servers such as Glassfish or Apache Tomcat.
Both these servers are bundled with Netbeans when you use
Netbeans Java profile (see table at Netbeans download page)