Patterns of Enterprise Application Architecture

Patterns of Enterprise Application Architecture

Martin Fowler

Language: English

Pages: 560

ISBN: 0321127420

Format: PDF / Kindle (mobi) / ePub

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

Client-Side Attacks and Defense

Java: A Beginner's Guide (6th Edition)

Gender Codes: Why Women Are Leaving Computing

Smart Machines: IBM's Watson and the Era of Cognitive Computing

















discussion is as independent as possible of any particular platform—where there are platform-specific sections I've indented them so you can see them and easily skip over them. Where useful I've put in UML diagrams to help explain them. When to Use It describes when the pattern should be used. Here I talk about the trade-offs that make you select this solution compared to others. Many of the patterns in this book are alternatives; such Page Controller (333) and Front Controller (344). Few

unaware of the higher layer. Furthermore, each layer usually hides its lower layers from the layers above, so layer 4 uses the services of layer 3, which uses the services of layer 2, but layer 4 is unaware of layer 2. (Not all layering architectures are opaque like this, but most are—or rather most are mostly opaque. Breaking down a system into layers has a number of important benefits. • • • • • You can understand a single layer as a coherent whole without knowing much about the other

it's a symmetrical view rather than my asymmetric layering scheme. I find this asymmetry useful, however, because I think there is a good distinction to be made between an interface that you provide as a service to others and your use of someone else's service. Driving down to the core, this is the real distinction I make between presentation and data source. Presentation is an external interface for a service your system offers to someone else, whether it be a complex human or a simple remote

immutable (assuming you would like to fix the mistake.) The database should detect the uniqueness problem, but it can only do that after my record goes into the system, and of course that might not happen until after the mistake. As a result, meaningful keys should be distrusted. For small systems and/or very stable cases you may get away with it, but usually you should take a rare stand on the side of meaninglessness. The next concern is simple versus compound keys. A simple key uses only one

findStatementString(); protected Map loadedMap = new HashMap(); public DomainObjectWithKey abstractFind(Key key) { DomainObjectWithKey result = (DomainObjectWithKey) loadedMap.get(key); if (result != null) return result; ResultSet rs = null; PreparedStatement findStatement = null; try { findStatement = DB.prepare(findStatementString()); loadFindStatement(key, findStatement); rs = findStatement.executeQuery();; if (rs.isAfterLast()) return null; result = load(rs); return result; } catch

Download sample