My last book, The Art of Java Programming (in Romanian), written together with my colleague and friend George Mardale was published at the end of 2005 in two volumes. 

The first volume is an introduction to object oriented programming using Java. You will find here an in-depth explanation of the OOP concepts (classes, objects, inheritance, polymorphism etc.) and how these concepts are materialized in Java. You will also find here an excellent introduction to threads, a nice explanation of the exception-handling mechanism and some very useful appendices on various Java topics. 

The second volume is dedicated to the presentation of fundamental algorithms and data structures, and their implementation in Java. The approach we took to presenting fundamental algorithms is original fun and easy to follow.

I also decided to make all the materials I wrote while teaching  at the Transilvania University public. Please note that most of the materials are old and in a rather brute, unpolished form, still you might find some useful information there, whether you are a student seeking for some information, or a teacher looking for some support material to start with. Most of the materials are in Romanian and available as PDF docs.