Introduction to Programming in Java
4. Installing the Java Development Kit
4.6. For Macintosh
Apple sets everything up for you. Sit back and relax.
The only drawback is that because Apple handles development and maintenance of Java on the Mac, there is usually a delay from the time that a new version is released by Sun and the time that the new version is released on the Mac. Also, getting the latest version sometimes requires an operating system upgrade.
Oh well, you can't have everything.