What do you recommend as a UI creator for Java (WYSIWYG). I have used Balsamiq for website mockups but I am creating a spec that needs to be close to exact - Balsamiq is great for rougher mockups, is there anything you would recommend.
The one in Netbeans is really good for layouts. I did a small application the other day and found it rather simple to use and quite intuitive (if you have worked with bean based editors before).
For larger layouts I was missing the ability to group things together (turning it into a single component layoutwise) like it is possible in Illustrator.
If you need "close to exact" why not do as you normally do (as already said: Netbeans, Eclipse...) and be exact ?
IMO the major advantage of having UI mocks (using Balsamiq) is that everyone (boss, customer, etc.) can see that the app is not nearly finished. Somehow I fail to see the point in making a mock that does not look like a mock.
From the very little experience I have with these horrible things, the NetBeans designer is the least worse.
I urge you, one and all, not to use graphic UI editors. While they may save time in the development phase, they create code that is bloated, mostly unreadable, and near-impossible to maintain. Unless something drastic has happened in the past few years, I'll continue to steer clear of them altogether.
Although Matisse has its headaches, I think it is the best option at the time, especially when there is big chance it will be improved in time to come; since two biggest players on market (Netbeans,myEclipse) supports it.
We are doing project using Matisse and are having many many problems with its layout policy (nobody can figure out its logics for 'intelligent' laying out components), but what I can say, this tool made us less problems than others. That can, ofcourse, vary from situation to situation, consider trying it, some little XML won't hurt you...
You can take a look at ForeUI, it allows you to switch the style of the mockup, you can create the mockup with hand drawn style and generate some pictures with hi-fidelity styles for documentation.