The Java SDK for Macintosh version 6.0 and the Eclipse IDE for Macintosh must be downloaded and installed separately. There is no combined download package for this combination of Java version and Eclipse IDE.
Downloading the Java software
Java 6.0 for Macintosh is only available (as of December 2006) as a Developer Preview. You must be an Apple Developer Connection member to download this software. Go to the Apple Developer Connection Java SE 6.0 Release 1 Developer Preview 6 site and either Sign In or Sign Up for a free memebership to download the software.
Downloading the Eclipse IDE
Go to the Eclipse Project Download Page and locate the link for the "Latest Release" (which should be at the top of the list of downloads). The latest release, as of September 21, 2006 was 3.2.1. Click on this link to go to the downloads page for this release. Find the link in the "Eclipse SDK" list for Macintosh platform, and click on that link. This should take you to a list of mirrors which have your selected software. Choose a mirror closest to you and click on the link. It shouldn't matter whether you choose an HTTP or FTP link. Your software download should begin automatically.
Installing the Eclipse IDE
The Eclipse IDE is delivered as a ".gzip" compressed file containing a ".tar" archive of the Eclipse IDE Java program files. Installation is accomplished by simply unzipping and untarring the archive.