اصول، الگوها و تمرینات JavaSpaces(TM) (سری جینی)

"Ever since I first saw David Gelernter's Linda programming language almost twenty years ago, I felt that the basic ideas of Linda could be used to make an important advance in the ease of distributed and parallel programming. As part of the fruits of Sun's Jini project, we now have the JavaSpaces technology, a wonderfully simple platform for developing distributed applications that takes advantage of the power of the Java programming language. This important book and its many examples will help you learn about distributed and parallel programming. I highly recommend it to students, programmers, and the technically curious." Bill Joy , Chief Scientist and co-founder, Sun Microsystems, Inc. JavaSpaces technology, a powerful Jini service from Sun Microsystems, facilitates building distributed applications for the Internet and Intranets. The JavaSpaces model involves persistent object exchange "areas" in which remote processes can coordinate their actions and exchange data. It provides a necessary ubiquitous, cross-platform framework for distributed computing, emerging as a key technology in this expanding field. This book introduces the JavaSpaces architecture, provides a definitive and comprehensive description of the model, and demonstrates how to use it to develop distributed computing applications. The book presents an overview of the JavaSpaces design and walks you through the basics, demonstrating key features through examples. Every aspect of JavaSpaces programming is examined in depth: entries, distributed data structures, synchronization, communication, application patterns, leases, distributed events, and transactions. You will find information on such vital topics as: Distributed data structures Synchronization techniques Loosely coupled communication Message passing Channel data structures for communication Application patterns such as replicated worker, command pattern, and marketplace Leases and automated lease renewal Using distributed events with spaces Handling partial failure with distributed transactions The official JavaSpaces specification from Sun Microsystems JavaSpaces Principles, Patterns, and Practice also includes two full-scale applications--one collaborative and the other parallel--that demonstrate how to put the JavaSpaces model to work. 0201309556B04062001 JavaSpaces(tm) Principles, Patterns, and Practice The Jini(tm) Technology Series Lisa Friendly, Series Editor Ken Arnold, Technical Editor Eric Freeman, Susanne Hupfer, and Ken Arnold ISBN 0-201-30955-6 2nd Printing August 1999 ADDISON-WESLEY An imprint of Addison Wesley Longman, Inc. Copyright© 1999 by Sun Microsystems, Inc. 901 San Antonio Road, Palo Alto, California 94303 U.S.A. All rights reserved. Duke(tm) designed by Joe Palrang. Preface . . . . . . . . . . . . . . . . . . . . . . . . . xv Foreword by David Gelernter . . . . . . . . . . . . . . . xix 1 Introduction. . . . . . . . . . . . . . . . . . . . . . . 1 2 JavaSpaces Application Basics . . . . . . . . . . . . . .21 3 Building Blocks . . . . . . . . . . . . . . . . . . . . .51 4 Synchronization . . . . . . . . . . . . . . . . . . . . .75 5 Communication . . . . . . . . . . . . . . . . . . . . . 107 6 Application Patterns. . . . . . . . . . . . . . . . . . 153 7 Leases. . . . . . . . . . . . . . . . . . . . . . . . . 197 8 Distributed Events. . . . . . . . . . . . . . . . . . . 217 9 Transactions. . . . . . . . . . . . . . . . . . . . . . 237 10 A Collaborative Application. . . . . . . . . . . . . . 247 11 A Parallel Application . . . . . . . . . . . . . . . . 281 12 Further Exploration. . . . . . . . . . . . . . . . . . 303 Appendix A: The Jini(tm) Entry Specification. . . . . . . 307 Appendix B: The Jini(tm) Entry Utilities Specification. . 313 Appendix C: The JavaSpaces(tm) Specification. . . . . . . 315 Index . . . . . . . . . . . . . . . . . . . . . . . . . . 334

This book contains the formal specification for the Jini technology. It offers a review of distributed computing fundamentals, an overview of the Jini architecture, and an introduction to the key concepts that are the source of the technology's simplicity and power—remote objects, leasing, distributed events, and a two-phase commit protocol. The formal specification provides the definitive description of every element of the Jini architecture, including detailed information on such topics as:

• Jini Discovery and Join protocols
• Jini Entry usage and the AbstractEntry class
• Jini Distributed Leasing concepts
• Jini Distributed Event programming model
• Jini Transaction model and semantics
• Jini Lookup service and lookup attribute schema
• Jini device architecture

As networks continue to pervade our personal and professional lives, there is an urgent call for the flexible and robust network infrastructure that Jini represents.

Annotation "JavaSpaces technology is a powerful Jini service from Sun Microsystems, Inc. that facilitates building distributed applications. The JavaSpaces model provides persistent object exchange "areas" in which remote Java processes can coordinate their actions and exchange data. JavaSpaces technology supplies a necessary, cross-platform framework for distributed computing with Jini technology." "This book introduces the JavaSpaces technology architecture and provides a comprehensive description of the model. Using an example-driven approach, this book shows you how to use JavaSpaces technology to develop distributed computing applications." "JavaSpaces Principles, Patterns, and Practice also includes two full-scale applications - one collaborative and the other parallel - that demonstrate how to put the JavaSpaces model to work."--BOOK JACKET. Title Summary field provided by Blackwell North America, Inc. All Rights Reserved "JavaSpaces technology is a powerful Jini service from Sun Microsystems, Inc. that facilitates building distributed applications. The JavaSpaces model provides persistent object exchange "areas" in which remote Java processes can coordinate their actions and exchange data. JavaSpaces technology supplies a necessary, cross-platform framework for distributed computing with Jini technology."--BOOK JACKET. "This book introduces the JavaSpaces technology architecture and provides a comprehensive description of the model. Using an example-driven approach, this book shows you how to use JavaSpaces technology to develop distributed computing applications."--BOOK JACKET. "JavaSpaces Principles, Patterns, and Practice also includes two full-scale applications - one collaborative and the other parallel - that demonstrate how to put the JavaSpaces model to work."--Jacket Jini technology, built on top of a Java software infrastructure, enables all types of digital devices to work together in a community organized without extensive planning or installation. In a Jini distributed system, Java programs interact spontaneously, enabling services to join or leave the network with ease, and allowing clients to view and access available services with confidence. A Jini system can link office components such as printers, faxes, and desktop computers and home-based networks such as: entertainment systems, cars, smart houses, and personal computers.This book contains the formal specification for the Jini technology, an overview of the Jini architecture, and an introduction to the key concepts that are the source of the technology's simplicity and power. Creating applications that run across a network of machines is notoriously difficult, even with Java, because creating distributed applications potentially entails coordinating the actions of many active processes. JavaSpaces, an exciting new coordination technology from the Java Software Division, promises to remedy this situation by providing a powerful, practical, high-level method of building a variety of distributed applications. With the JavaSpaces model, programmers build distributed applications by gluing Java processes together into ensembles that work together to accomplish a common goal. The model is simple yet powerful enough to implement the most advanced distributed applications and is ideal for building commercial-quality distributed systems. This book is the formal introduction of Jini technology to the world. In addition to presenting the official specification, it discusses the aim and vision of the technology. Ken Arnold, one of Sun's key designated deputies overseeing Ini's future development, presents the specification and gives insight into future plans and upgrades for Ini. Ini technology makes computers and devices able to quickly form impromptu systems unified by a network. The importance of this technology extends the capabilities of mobile networking. Whether you have to sit in one place to do your work or you can move around creates a big difference in competitive advantage. The Java programming language is the key to making Jini technology work. "This book contains the formal specification for the Jini technology, an overview of the Jini architecture, and an introduction to the key concepts that are the source of the technology's simplicity and power. The formal specification provides the definitive description of every element of the Jini architecture, including detailed information on such topics as Jini Discovery and Join protocols, Jini Entry usage and the Abstract Entry class, Jini Distributed Leasing concepts, Jini Distributed Event programming model, Jini Transaction model and semantics, Jini Lookup service and lookup attribute schema, and Jini device architecture."--Jacket