Java Network Monitor

Please recommend a good network monitor that开发者_如何转开发 monitors all the Request and the responses made by my java program and gives me detail on the Headers.

Wireshark. Not Java-specific, but very good.

Wireshark's already been mentioned. Microsoft netmon also works quite well. Compared to Wireshark, it doesn't dissect as many different protocols out of the box, but IMO it does a somewhat better job with some of the protocols it does handle. Since you've said nothing about what protocols you're using (outside of mentioning HTTP in the title), it's hard to guess which will work better for your purposes. If you are just using basic HTTP, I'd call is pretty close to a tossup -- they both handle this quite nicely.