Patterns of Enterprise Application Architecture [Hardcover]

Martin Fowler (Author)

Book Description

ISBN-10: 0321127420 | ISBN-13: 978-0321127426 | Publication Date: November 15, 2002 | Edition: 1

Developers of enterprise applications (e.g reservation systems, supply chain programs, financial systems, etc.) face a unique set of challenges, different than those faced by their desktop system and embedded system peers. For this reason, enterprise developers must uncover their own solutions. In this new book, noted software engineering expert Martin Fowler turns his attention to enterprise application development. He helps professionals understand the complex -- yet critical -- aspects of architecture. While architecture is important to all application development, it is particularly critical to the success of an enterprise project, where issues such as performance and concurrent multi-user access are paramount. The book presents patterns (proven solutions to recurring problems) in enterprise architecture, and the context provided by the author enables the reader to make the proper choices when faced with a difficult design decision.

Editorial Reviews

From the Back Cover

The practice of enterprise application development has benefited from the emergence of many new enabling technologies. Multi-tiered object-oriented platforms, such as Java and .NET, have become commonplace. These new tools and technologies are capable of building powerful applications, but they are not easily implemented. Common failures in enterprise applications often occur because their developers do not understand the architectural lessons that experienced object developers have learned.

Patterns of Enterprise Application Architecture is written in direct response to the stiff challenges that face enterprise application developers. The author, noted object-oriented designer Martin Fowler, noticed that despite changes in technology--from Smalltalk to CORBA to Java to .NET--the same basic design ideas can be adapted and applied to solve common problems. With the help of an expert group of contributors, Martin distills over forty recurring solutions into patterns. The result is an indispensable handbook of solutions that are applicable to any enterprise application platform.

This book is actually two books in one. The first section is a short tutorial on developing enterprise applications, which you can read from start to finish to understand the scope of the book's lessons. The next section, the bulk of the book, is a detailed reference to the patterns themselves. Each pattern provides usage and implementation information, as well as detailed code examples in Java or C#. The entire book is also richly illustrated with UML diagrams to further explain the concepts.

Armed with this book, you will have the knowledge necessary to make important architectural decisions about building an enterprise application and the proven patterns for use when building them.

The topics covered include:

Dividing an enterprise application into layers

The major approaches to organizing business logic

An in-depth treatment of mapping between objects and relational databases

Using Model-View-Controller to organize a Web presentation

Handling concurrency for data that spans multiple transactions

Designing distributed object interfaces

0321127420B10152002

About the Author

Martin Fowler is an independent consultant who has applied objects to pressing business problems for more than a decade. He has consulted on systems in fields such as health care, financial trading, and corporate finance. His clients include Chrysler, Citibank, UK National Health Service, Andersen Consulting, and Netscape Communications. In addition, Fowler is a regular speaker on objects, the Unified Modeling Language, and patterns.

0321127420AB07242003

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Product Details

• Hardcover: 560 pages
• Publisher: Addison-Wesley Professional; 1 edition (November 15, 2002)
• Language: English
• ISBN-10: 0321127420
• ISBN-13: 978-0321127426
• Product Dimensions: 9.3 x 7.6 x 1.3 inches
• Shipping Weight: 2.3 pounds (View shipping rates and policies)
• Average Customer Review: 4.4 out of 5 stars  See all reviews (73 customer reviews)
• Amazon Best Sellers Rank: #28,494 in Books (See Top 100 in Books)
  • #17 in Books > Computers & Technology > Hardware > Microprocessors & System Design
  • #19 in Books > Computers & Technology > Hardware > Design & Architecture
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Customer Reviews

Most Helpful Customer Reviews

87 of 92 people found the following review helpful:

4.0 out of 5 stars Great book, but nothing particularly new, February 20, 2003

By 

The Last Person You'd Expect (Seattle, WA United States) - See all my reviews
(VINE VOICE)   

This review is from: Patterns of Enterprise Application Architecture (Hardcover)

I agree wholeheartedly with an above post which pointed out that the subject material is mostly known to the average enterprise developer. I am at best an average developer and found I'd already thought of much of this stuff myself.

One thing I would like to add is that this book was still excellent reading and skimming through the patterns sparked my creative energies. I find that when I read through it, even if I 'know' the patterns already, it helps me explore their organization and consequences.

I was disappointed that I wasn't blown away with helpful new concepts, but quite happy with my purchase all the same. Buy this if you want a thorough guide to EAA and maybe some enjoyable afternoon reading.

(The following was added about 2 months after the original review) After owning this book for awhile, I've found it more and more indispensible. My original review, above, mentions that few of the concepts seem new, however, now that I've read it more thoroughly and applied some of the concepts, I don't think that 'mind-blowing originality' is what I should have been looking for.

Fowler's 'Refactoring' is another example of a great book without any stunningly original concepts. Like Refactoring, PEAA can serve as a great guide to page through when you're stuck on a project and need to review your options.

26 of 26 people found the following review helpful:

5.0 out of 5 stars The right path to creating enterprise applications., October 3, 2003

By 

Charles Ashbacher (Marion, Iowa United States) - See all my reviews
(TOP 500 REVIEWER)    (VINE VOICE)    (HALL OF FAME REVIEWER)   

This review is from: Patterns of Enterprise Application Architecture (Hardcover)

Fowler avoids giving a precise definition of an enterprise application, preferring to list a set of characteristics that most share. In general, they are very large systems, with many user interface screens used to concurrently access and update an enormous amount of data. In nearly all cases, the data must be persistent, in fact it most often is very persistent, meaning that it has to live through iterations of the software, alterations of the operating system, changes in the hardware, and staff and programmer turnover.
Furthermore, enterprise applications usually must communicate with other applications, which are often just as large and complex. Examples include payroll and patient records, credit card processing, insurance claim processing, banking, and foreign exchange trading. In short, most of the programs that run the modern global economy, which are many of the most complex software projects currently in use. Finally, the programs must be constructed so that they can be "easily and quickly" changed by people who did not create them to adapt to conditions that can change very quickly and often without any input from the programmer. With so much at stake, there must be a set of best practices, which is what is captured in this book.
The patterns of software construction explained by Fowler are generally in the small, in the sense that they describe specific operations rather than demonstrate a large architectural form. Each of the specific patterns is presented by first listing a one-sentence description of the purpose of the pattern and a UML diagram illustrating the structure. This is followed by sections describing how the pattern works, when to use it and one or more examples demonstrating specific implementations of the pattern using source code skeletons. Both C# and Java are used in the demonstrations, which does not create an understandability problem. The languages and contexts are so similar that anyone who can understand either one will have no problem reading and understanding the code.
Some examples of the fifty one patterns listed on the inside front cover are:

Lazy load - where an object will load only the data currently needed, but does maintain links to all other data that may be needed.

Front controller - a single handler object that consolidates all requests made for a web site. It can then send requests to the specific objects for services such as security, internationalization issues and specific displays targeted for particular users and locations.

Optimistic offline lock - used to prevent conflicts when concurrent business transactions are executing. The solution is to roll back the transaction when a conflict is detected.

Server session state - keeps the data for the session stored on a server in a serialized form.

While the examples are often of necessity extremely simple, they do illustrate some of the most effective and tested solutions to common software development problems. Therefore, this is a book that no builder of software that can be considered an enterprise application should be without. It is hard to believe that there is an enterprise application being constructed anywhere that does not involve the solving of many of the problems listed in this book.
My only complaint is the occasional bad English that appears. For example, on page 100 there is the phrase, "The only reason I've concentrating on Java . . . " and on page 119 the phrase "One factor that comes into this is comfortable used the development team is . . . " appears. While no book is error free, this type of error is frequent enough to make one wonder about the quality of the final editing.
There is nothing harder than making effective and efficient software that will run the IT equivalent of forever. That is what enterprise applications are supposed to do and if you are one of the minions tasked with doing your part to build one, then put yourself on the right path and read this book. You and everyone else who interacts with the software will be rewarded with a better experience.

Published in the online "Journal of Object Technology", reprinted with permission.

34 of 37 people found the following review helpful:

5.0 out of 5 stars Best J2EE / .Net Design Pattern Book, December 13, 2002

By 

Stephen Molitor (Shrewsbury, MO United States) - See all my reviews

This review is from: Patterns of Enterprise Application Architecture (Hardcover)

This is the best book I've found on J2EE and .Net patterns. I think it's destined to become a classic. I found the discussions on when to distrbute ('sell your favorite grandmother first'), Unit Of Work, Domain Model and Data Mapper patterns extremely useful. It has changed the way I think about enterprise applications.

I think it fits somewhere between the original 'Design Patterns' book, by Gamma, et al, and a book like 'J2EE Patterns' in terms of its scope. 'Design Patterns' describes existing patterns that are applicable to any kind of application. 'J2EE Patterns' describes patterns in terms of one platform (although many of them apply to other platforms as well.) Fowler's book describes a set of patterns that work with a certain kind of application, business apps, but that are applicable to more than one platform.

It's better than the 'J2EE Patterns' book, which doesn't do a good job explaining which parts of J2EE to avoid, and which 'patterns' are in fact workarounds for problems in the platform itself. (For example, the 'Composite Entity' pattern.)

I have to strongly disagree with the first reviewer. Fowler does explain which patterns work best on which platform. The first section of the book gives a good road map for deciding which set of patterns to use for your app. He mentions explicitly that .Net pulls you in the direction of Table Module, but that with J2EE you would be less likely to use that pattern.

As far as the patterns being available in frameworks, I still find it useful to know about the patterns the framework implements. That way you know which framework to select. We recently went through an O/R mapping tool selection process. Reading the Unit Of Work, Data Mapper, Repository, Lazy Load and Identity Map chapters helped *immensely* in that process. Likewise reading the Front Controller pattern gave me some new ideas on how best to utilize the Struts framework. I totally disagree with the notion that "learning about the patterns that are associated with these frameworks will provide little value". Ignorance is definitely not bliss here.

Finally, the idea that because the book 'just' collects and names patterns that already exist somehow decreases its value is hogwash. These are tried and true patterns that many developers have found useful. Naming and clearly describing common patterns is very helpful. This is exactly what the original 'Design Patterns' book did. By this logic, I guess the original reviewer would have given 'Design Patterns' only 3 stars.

It's a great book.