Clearly, one significant part of Java is its application in distributed systems. While the Java 2 platform, enterprise edition (J2EE) model of server side components is the dominant approach to this problem, Java also provides other, more novel and innovative methods.

The book provides a very concise, readable, and practical introduction to the JavaSpace model, and to how to apply it in a number of simple applications. It is intended to supplement the popular JavaSpaces Principles, Patterns, and Practice [1], and as such, does not provide the same level of introductory materials and examples.

The emphasis of this book is more on the proper design and application of JavaSpace components. The first chapters discuss the design and use of entries, the basic elements in a space, and the data structures built from them and stored in a space-based system. The second part discusses the mechanics of using a space, and some idioms for implementing standard models like remote events and mobile code using spaces. The third part discusses applications of a space-based model, and some of the issues involved in developing, debugging, and maintaining such a system.

The examples are all very simple and clear, though they are also short. I consider this last feature to be an advantage. The book meets its goal of providing practical insight and examples for an introduction to using JavaSpaces.

JavaSpaces are not yet a very widespread approach to distributed systems implementation, but with roots in the tuple spaces of Linda, and cousin derivative T-Spaces at IBM, they clearly embody a unique and useful paradigm for distributed computing. I recommend this book, and its precursor companion, to anyone interested in current implementations of distributed systems.