From the web site: "Fiddler is a Web Debugging Proxy which logs all HTTP(S) traffic between your computer and the Internet. Fiddler allows you to inspect all HTTP(S) traffic, set breakpoints, and "fiddle" with incoming or outgoing data. Fiddler includes a powerful event-based scripting subsystem, and can be extended using any .NET language."
However, it doesn't work when you want to look at Java web service (SOAP) traffic generated by the JAX-WS support in Netbeans (i.e. Metro).
I have a number of command line tools that I use to generate various types of traffic with a command line like:
java -jar SomeProgram.jar
To get Fiddler to work, you need to change the command line to:
java -DproxySet=true -DproxyHost=127.0.0.1 -DproxyPort=8888 -jar SomeProgram.jar
Fiddler uses port 8888 as default.