To quote from the bikemonkey link:
By downloading these binaries, you certify that you are a Licensee in good standing under the Java Research License of the Java 2 SDK, and that your access, use, and distribution of code and information you may obtain at this site is subject to the License. Please review the license at http://java.net/jrl.csp, and submit your license acceptance to Sun.
The Mac OS X work is based heavily on the BSD Java port, which is licensed under the JRL. The BSDs develop Java under the JRL; FreeBSD has negotiated a license with Sun to distribute FreeBSD Java binaries based on the JRL sources.
As the Mac port stabilizes, I am merging my work upstream into the BSD port, and in turn, it is a goal of the FreeBSD Java project to merge their work into OpenJDK. I've signed a Sun Contributor Agreement in preparation for this, and an OpenJDK Porters group has been proposed: http://thread.gmane.org/gmane.comp.java.openjdk.general/630
While the JRL makes this initial port possible, OpenJDK's GPLv2+CE licensing makes development and distribution far simpler. I hope to contribute this work to OpenJDK as soon as is feasible.
So, while IANAL, it appears this can only be used under JRL. But JRL only permits Research Use, defining it as:
"Research Use" means research, evaluation, or development for the
purpose of advancing knowledge, teaching, learning, or customizing the
Technology or Modifications for personal use. Research Use expressly
excludes use or distribution for direct or indirect commercial
(including strategic) gain or advantage.
So I suspect that running hadoop client libraries at a commercial search engine does not fall under Research Use.