The Continuing Revolution

The Continuing Revolution

 

The initial release of Java was nothing short of revolutionary, but it did not mark the end of Java’s era of rapid innovation. Unlike most other software systems that usually settle into a pattern of small, incremental improvements, Java continued to evolve at an explosive pace. Soon after the release of Java 1.0, the designers of Java had already created Java 1.1. The features added by Java 1.1 were more significant and substantial than the increase in the minor revision number would have you think. Java 1.1 added many new library elements, redefined the way events are handled by applets, and reconfigured many features of the 1.0 library. It also deprecated (rendered obsolete) several features originally defined by Java 1.0. Thus, Java 1.1 both added and subtracted attributes from its original specification.

 

The next major release of Java was Java 2. Java 2 was a watershed event, marking the beginning of the “modern age” of this rapidly evolving language! The first release of Java 2 carried the version number 1.2. It may seem odd that the first release of Java 2 used the 1.2 version number. The reason is that it originally referred to the version of the Java libraries, but it was generalized to refer to the entire release, itself. Java 2 added support for a number of new features, such as Swing and the Collections framework, and it enhanced the Java Virtual Machine and various programming tools.

 

Java 2 also contained a few deprecations. The most important affected the Thread class in which the methods suspend( ), resume( ), and stop( ) were deprecated. The next release of Java was Java 2, version 1.3. This version of Java was the first major upgrade to the original Java 2 release. For the most part it added to existing functionality and “tightened up” the development environment. In general, programs written for version 1.2 and those written for version 1.3 are source-code compatible. Although version 1.3 contained a smaller set of changes than the preceding three major releases, it was nevertheless important.

 

The current release of Java is Java 2, version 1.4. This release contains several important upgrades, enhancements, and additions. For example, it adds the new keyword assert, chained exceptions, and a channel-based I/O subsystem. It also makes changes to the Collections Framework and the networking classes. In addition, numerous small changes are made throughout. Despite the significant number of new features, version 1.4 maintains nearly 100 percent source-code compatibility with prior versions. This book covers all versions of Java 2. Of course, most of the material applies to earlier versions of Java, too. Throughout this book, when a feature applies to a specific version of Java, it will be so noted. Otherwise, you can simply assume that it applies to Java, in general. Also, when referring to those features common to all versions of Java 2, this book will simply use the term Java 2, without a reference to a version number.