I am pretty sure that you can download earlier editions of Bruce Eckel's - Thinking in Java from his site. http://www.mindview.net/Books/TIJ/.

Here is a free online version of Core Servlets & JSP, 1st Edition http://www.coreservlets.com/

Also Oreilly has a free .pdf article archive you might want to check out http://java.oreilly.com/