Foreword

Integration is currently a hot topic. We live in an increasingly asynchronous world in which we need to interact with a bewildering range of systems, so our software applications need to support a variety of conversation patterns with disparate collaborators.

Software that helps developers tackle this complexity is crucial. In the 2000s, Struts, Spring, and Hibernate replaced in-house web MVC, configuration, and persistence code with superior, battle-tested, and well-documented open source code. Similarly today, integration is core to so many applications that we need quality, generic infrastructure in place of ad hoc solutions.

Spring Integration is a great choice to address these infrastructure requirements. Too many open source projects reinvent every wheel in sight. Spring Integration does not, and is stronger for it. It explicitly builds on established best practices and existing software. Spring Integration was inspired by one of the classic books on enterprise software: Hohpe and Woolf’s Enterprise Integration Patterns (Addison-Wesley, 2003). The developers chose to follow the vocabulary that book introduced, meaning that their code benefits from the thinking and experience that’s evident in the book and is easy for developers familiar with those patterns to adopt. Spring Integration also builds on the powerful and proven Spring Framework. It extends Spring’s POJO programming model, making it a natural choice for the millions of developers already familiar with Spring. If you’re a Spring developer, learning Spring Integration won’t feel so much like learning a new framework as like picking up a part of the Spring Framework core that you haven’t yet applied. You’ll be able to focus on mastering architectural concepts without wrestling with an unfamiliar API. Spring Integration also applies proven Spring values such as portability, with the result that it can be used in a wide range of environments.

Spring Integration is set to become an increasingly important project within the Spring Portfolio. I believe this book will become the definitive work on it.

The authors are uniquely qualified to write about the topic. Mark Fisher is the creator and lead of Spring Integration, and all the authors are contributors. Their daily involvement in the open source project has ensured that the book is up to date with Spring Integration 2.0 features and best practices. Mark, Marius, Iwein, and Jonas have a wealth of worldwide consulting experience helping customers solve integration problems. This extensive and current hands-on experience underpins their writing and offers great value to the reader.

The authors do an excellent job of putting Spring Integration in context. Rather than merely explain how to use Spring Integration, they discuss common business problems, the trade-offs between potential solutions, and how Spring Integration can be applied to implement them. The first few chapters explain how Spring Integration grows naturally out of the Spring Framework.

The examples are well chosen: easy to grasp, yet realistic enough to communicate real-world problems. A good balance between code examples and explanation develops the reader’s understanding at a steady pace.

There are many highlights, but I particularly like chapter 18, “Testing.” In this, as in many other chapters, you’ll find a wealth of good advice based on experience, which will save you a lot of time debugging. What kinds of tests will give you the most bang for your buck? How do you test your configuration? How do you figure out what’s going on with an endpoint that has no output? You’ll find thoughtful answers to these and many other questions.

Finally, Spring Integration in Action is well written. Too often technical books are clumsily and sloppily worded, making them hard work to plow through and potentially confusing. This book is an exception, being enjoyable to read and always clear and to the point. Excellent, uncluttered diagrams elucidate many key points.

I hope you enjoy reading Spring Integration in Action. I did.

ROD JOHNSON
FOUNDER OF THE SPRING FRAMEWORK