Java SE 6:

The newest release of Java is called Java SE 6, and the material in this book has been updated to reflect this latest version of Java. With the release of Java SE 6, Sun once again decided to change the name of the Java platform. First, notice that the “2” has been dropped. Thus, the platform now has the name Java SE, and the official product name is Java Platform, Standard Edition 6. As with J2SE 5, the 6 in Java SE 6 is the product version number. The internal, developer version number is 1.6.

Java SE 6 builds on the base of J2SE 5, adding incremental improvements. Java SE 6 adds no major features to the Java language proper, but it does enhance the API libraries, add several new packages, and offer improvements to the run time. As it relates to this book, it is the changes to the core API that are the most notable. Many of the packages have new classes, and many of the classes have new methods. These changes are indicated throughout the book. In general, the release of Java SE 6 serves to further solidify the advances made by J2SE 5.