Currently (June 2009), the Mac OS (10.5.7) defaults to Java 1.5. You can change this setting using the Java Preferences program in /Applications/Utilities. Drag 1.6 to the top of the list. Run “java -version” from a command line to see which version the system will use. You should go ahead and switch it to use the latest Java, but you’re not done yet.

The Java Preferences panel affects which version of Java is run, but not which JDK is used. For development, you need the correct Java JDK. Set it via JAVA_HOME.

A simple and oft-recommended way to set JAVA_HOME on the Mac is to point it to “/Library/Java/Home/”. However, this location is for the system’s default, which is currently 1.5.

You want to use 1.6, so point to it directly at

/System/Library/Frameworks/JavaVM.framework/Versions/1.6/Home

If you follow that path, you’ll see that there’s also a 1.6.0 directory. But selecting 1.6 means that it will point to the latest 1.6.x version. Use 1.6.0 if you need to specify 1.6.0 specifically.

Now, where to set that variable… Common advice is to set it using a shell export such as

export JAVA_HOME=/System/Library/Frameworks/JavaVM.framework/Versions/1.6/Home

Add that line to your ~/.profile or your ~/.bashrc and you’re done. That will certainly work for any terminal compiling that you do. But it won’t work for programs installed in your /Applications folder that you don’t run from the command line.

To get those applications to ’see’ the environment variable, use the Doug McClure’s free program RCEnvironment. It’s a System Preferences pane that will edit ~/.MacOSX/environment.plist for you. You could just edit the file, but it’s XML, so let RCEnvironment balance the tags for you.

Finally, if you’re using an ant-based build, you can easily see which sdk is being used in the build process by running

$ ant -diagnostics

…and reading the through the output.

You could click “Do it later,” but that just kicks the problem down the road. Worse, it violates the DIO principle which says that you should strive to encounter new information only once: Do It Once. Handle it, delete it, change it into something else for later, or break into smaller tasks, but whatever you do, Do It Once. The DIO approach prevents the buildup of a half-done, to-do-later, on-the-list, undone, no-progress landfill that’s too big to attack and too disorganized to improve.

With respect to software maintenance, what if you could scan and update all of your installed software automatically? Well you can’t so forget it.

What makes the automation of updating hard is that every software maker is free to use their own versioning notation and semantics. And while software installation on the Mac is considerably simpler than on Windows, there is no standardized way that also provides hooks for Automation Managers. So AppFresh’s challenge is to detect and facilitate software updating. Viewed this way, it’s a terrific program.

So the way to use it is to open it to the “Update Available” panel. Right click on the columns in the main view and make sure “Installed Version” and “Latest Version” are showing. Then:

1. See what version you have for any item in the “Installed” column. Click an item, then click the “Release” tab on the right sidebar to see the release notes for the latest update. Decide to update or not. If not, right click on the item and choose “Skip Update”. You can wait for the next one.

2. We’re going to update a program. Was the program easy to install? These are the ones you just unzipped or double-clicked the .dmg file, then dragged to the application folder. If so, click the down-arrow “Update” button. Watch the progress. If it doesn’t disappear from the update list, then click on the “Updating” item on the left sidebar and find the program. If there’s an error, try again. If it says, “Installer run needed”, then go find the installer package for the new version in your downloads folder and double click it.

3. If it’s a big-installation package like Microsoft Office, or you know it has its own updater like Adobe Updater, then update it outside of AppFresh. For example, Microsoft AutoUpdate is buried somewhere; I find it by typing ‘auto’ into Quicksilver or Google Quick Search Box.

4. If AppFresh continues to list a program under “Update Available” when you’ve already updated it, then right click on the item and choose “Skip Update”. Or you may see that the “Installed” column still shows the old version, even though you’ve updated it. This means that the software lists only its main version, even though we, and AppFresh, know there’s a newer version with a subversion number. It’s ok. Just choose “Skip Update”.

5. If there’s a program you don’t use often or don’t want to mess with (say a system program), then right click on it an choose “Exclude”. To see what you’ve exclude, and maybe unexclude a program you want to check on or update, look in the “Exclude” panel in the preferences. You’ll still be reminded about updates when you run the program later, assuming you have its “Check for Updates” enabled. So you won’t miss any updates.

It may look like a lot, but its easy to race through the list once you’ve done it a few times. Then your machine is updated, you won’t be interrupted while you’re working, and you’ve dealt with software maintenance simply and Done It Once.

It turns out that the developer of QuickSilver has joined Google and yesterday released a sequel called the Google Quick Search Box. Reviews say that it’s not quite powerful enough to replace QuickSilver yet. But some may prefer its simplicity and appealing interface. It can integrate with Spotlight, if activated via a preference panel.

What makes these tools so powerful is their predictive typing and noun/verb metaphor. With just a few keystrokes, you can select an album, then start it playing. Or you can pick a contact, then open a new email already addressed. The possibilities grow as you get better at it…