it's a miniseries: *, the Good Parts

http://www.amazon.com/Java-Good-Parts-Jim-Waldo/dp/059680373...

http://www.amazon.com/PHP-Good-Parts-Delivering-Best/dp/0596...

I picked these because the big box book resellers stock them (I think you're looking for background on things like primitives/autoboxing, java.util.concurrent, the JVM's startup options, profiling/debug tools, and maybe tips that make rhickey's clojure source easier to read):

http://www.amazon.com/Core-Java-TM-I-Fundamentals-8th/dp/013...

http://www.amazon.com/Java-Good-Parts-Jim-Waldo/dp/059680373...