Java Foundation Classes:

The javas Foundation Classes (JFC) encompass a huge range of enhancements.  There is now support for assertive technologies along with Accessibility API, a java 2-D API enhanced graphics and imaging, and Swing for a new set of GUI a component, in +-addition to the AWT components.

Collections:

The Collection API makes working along with groups of objects much simpler.  Prior to java 1.2 you mostly used the earlier Vector and hashtable classes, as well as the enumeration interface. Above, you could work along with things such as circular linked lists, balanced trees, and simplified array sorting.

Further to these changes, a whole host of changes to methods, classes and packages have given extra functionality. These modifications are documented throughout this book.