Java is unprecedented among programming languages in gaining popularity so quickly. Nearly every professional programmer I know is learning to use it, motivated by the belief that it will be the next major application language. Many programmers were slow to embrace C++, and they do not want to be late out of the starting gate again. For those who already know C and C++, this book is the perfect starting point for learning about Java. The writing style is succinct, the organization is well thought out, and the coverage flows quickly. In addition, the publisher has priced the book to make it a bargain.

Although it is a great introduction to Java, the book is intended as a high-level Java reference. Toward this end, the second half consists of reference material that describes Java’s standard application program interface (API). There is a separate chapter for each Java package, which consists of class and interface declarations. Public methods and data are listed within the declarations. The public methods and data are listed only by name, without additional description, so one must seek details elsewhere. The author states that once one has learned the details elsewhere, this quick reference is all that is needed to refresh one’s memory. As books go, the reference material succeeds in providing a good overview. However, it is unclear whether a paper document can compete with hypertext class browsers, which can effectively provide both overview and detail. Until good browsers are available, the class listings and various indexes of methods, exceptions, and such will be useful.

In the past, when one learned a new programming language, one first learned basic syntax; structures for data, control, and declarations; and expression syntax. These were only minor aspects of writing useful programs, since one also typically had to learn to use the system interface, which could vary widely across platforms. Java, like most other programming languages, has a small set of basic language structures. But it is novel because it also has extensive, well-defined classes that define an API to standard operations for graphics, network communication, I/O events, and much more. To become expert with Java, one is likely to spend much less time learning the basic language structures than learning to use the API classes. With that in mind, this book presents the basic language structures well to those already familiar with C++. It is, understandably, much less thorough in presenting the API.

The book is divided into five parts. The first part presents all the basic language structures. Its coverage includes primitive types, classes, and exceptions. It is written at just the right level for experienced C++ programmers. The second part consists of a number of well-conceived example programs that illustrate the syntax and API. Examples include event handling, GUI components, file I/O, a client/server implementation, and threads. Careful commentary provides an overview of the examples, but one must dig into the code to understand them well, and one must search within the reference material for explanation. The book is self-contained, and the examples are well worth the effort. There are other Java books that explain code examples with line-by-line commentary, but this one does not. Many programmers learn a language best by studying code; they will be right at home here. Not only do the examples serve as a good introduction to Java, they serve the valuable role of working examples that one can review when approaching similar programming problems.

The third part of the book covers miscellaneous topics such as events, fonts, and applet syntax and security. The fourth and fifth parts describe the API packages and provide cross-reference indexes. A long glossary defines Java’s many special terms. The main index is thorough, but because page references are ordered numerically without bold type, one must often visit many pages before finding relevant explanatory material.

Overall, the writing is clear, though there was probably a hurry to get the book to press. The haste is apparent in an occasional confusing paragraph or grammatical error. Comments in example code contain a number of typos. None of the errors is serious. Sources and executables for many of the example applets are available at http://www.ora.com/catalog/javanut/examples (the URL given in the book itself is incorrect), and it is worth your while to experiment with them. All in all, this is a valuable book that all Java programmers will find useful.