Porting a Swing App from Java5 to Java6

05 May 2008

We’ve got a fairly significant Swing application that we couldn’t port to Java6 until Apple released a compatible JVM. Fortunately that finally happened last week.

I’m down at JavaOne this week and was motivated to take a stab at resolving the couple dozen compilation problems and get things running.

It really wasn’t too difficult. The most annoying changes I had to deal with concerned our usage of old versions of the SwingWorker and JDIC classes. They have now been integrated into the platform with slightly different interfaces and aren’t source-level compatible with their predecessors.

I took a stab at swapping in a couple of new L&Fs, mainly Nimbus and Substance. As far as Nimbus goes, the build I grab’d from SwingLabs seemed to have a couple of problems dealing with custom UIs (a NPE attempting to replace the default SplitPaneUII). I didn’t see a build of the Java6 Update N available for the Mac so I couldn’t check to see if the problems I was seeing have been fixed. The new button UIs are definitely an improvement but I’m not quite sure how I feel about the scroll bars.

Substance was more or less a drop-in replacement that worked out of the box. The only problems I had was when I tried to apply particular themes or skins. Depending on

UIManager.setLookAndFeel(new SubstanceBusinessLookAndFeel()); BAD

SubstanceLookAndFeel.setSkin(new MistSilverSkin()); GOOD

*UIManager.setLookAndFeel(new SubstanceLookAndFeel()); *

The former resulted in ClassCastExceptions between an internal Apple Aqua panel and a Substance panel. I suspect it just hasn’t been tested extensively with the Apple JVM.