JAVA...
Building
Java Executables
An online book by universalteacher.com
covering topics Executable Java Archives, The .EXE
Solution and Java Native Interface.
Java
Application Development on Linux 
Free Java
book from Bruce Perens' Open Source Series. Written
for Java and Linux developers alike, Java Application
Development on Linux is the hands-on guide to the
full Java application development
lifecycle on Linux.
Apache
Jakarta Commons: Reusable Java Components 
Free Java
book from Bruce Perens' Open Source Series. Using
the Apache Jakarta Commons reusable Java components,
you can leverage the work of the global open-source
community to solve common programming problems reliably,
quickly, and inexpensively.
JXTA

This free book presents a
guided tour of the JXTA platform, including all of
the critical information required to begin producing
P2P solutions built on top of JXTA.
Who's
Afraid of Java
Free online
Java book by Steve Heller. Contents include Hardware
Fundamentals, Basics of Programming, More Basics,
Functional Literacy, Taking Inventory, Tying up Loose
Ends and Java Q&A.