I assume you've clicked on this post because you're one of the NetBeans users who is unhappy about the scanning classpath dialog. It takes so long. And all you can do is sit and wait. Yes, I know, this is annoying. So you may want to try some of my tips which could help:
1. Which NetBeans version do you use?
For users with NetBeans 4.0, 4.1 EA, beta or 4.1 development builds: upgrade to NetBeans 4.1 rc1 and install NetBeans from installer. Only several weeks divide us from 4.1 release, thus the quality of the build is very high. Currently installer pre-parses all JDK sources which causes NetBeans to only check JDK sources instead of full parse. That's why installation takes longer, but thanks to this you don't have to wait so much when IDE starts and scans JDK. This won't help with scanning your project, but helps a lot for scanning of JDK.
2. Is your project on a network drive?
Bad idea! If there is a possibility to have it on local drive, put it there. The faster the disc, the better. NetBeans has to scan all your files for changes (so that it has up-to-date information for refactoring, code completion and other features). Having project on network drive slowes it down a lot. Note for Sun employees - your homes are on network mapped drives. Try to put your projects on your local hard-drive and you may be surprised about the difference.
3. Is your JDK on a network drive?
I know, you may ask, who would do it. There are people who really have JDKs on network drives, trust me. They should try to put it on their local drive instead.
4. How many projects do you have opened?
Try to keep the number of projects on minimum. NetBeans will not parse their sources and thus startup with opened projects will be faster.
5. Any other ideas?
Ugh, no. You got me. Well you can always upgrade your computer, but this is probably not the advice you would like to hear from me. On the other hand it helps. Fast CPU, fast hard-drive and more than 512 MB memory boosts any Java application, not only NetBeans. Before you will write me angry posts about me forcing you to upgrade hardware - it's just an idea, don't shoot me for it.
There are plans for improvements of scanning classpath in next release, so stay tuned.
I have also tips what you could do if your project sources are of 1 GB size on a network share
and you can't do anything about it (don't take them seriously
- make yourself a coffee - we all drink a lot of coffee, don't we?
- train your abs - people from IT do need excercise
- call your girlfriend or your mother - they will be happy you call them often
- play your favourite computer game - but watch out to come back to the IDE
- walk your dog - but not too often or the dog may run out of liquids
- write your blog - you'll get popular!