About this Book

Mule, as the preeminent, open source integration platform, provides a framework for implementing integration solutions. The book will give you the tools for using Mule effectively. It’s not a user guide; Mule’s comprehensive user guide is available online already. Instead, it’s a review of Mule’s main moving parts and features put in action in real-world contexts. After a little bit of history and some fundamentals of configuring Mule, we’ll walk you through the family of components that you’ll use in your projects. We’ll then review some runtime concerns such as exception handling, transactions, security, and monitoring. Then we’ll delve into advanced subjects such as programming with Mule’s API, tuning, and working with complementary technologies such as BPM and CEP.

Who should read this book

This book is primarily targeted at developers who want to solve integration challenges using the Mule platform. It’s also useful for architects and managers who are evaluating Mule as an integration platform or ESB solution. Additionally, system administrators tasked with supporting Mule instances will find this book, part 2 in particular, of value.

How to use this book

Each chapter in this book builds on the previous chapter. Readers new to Mule are encouraged to read the book with this in mind. Readers familiar with Mule 2.x will find part 1 particularly useful, as it describes and provides examples of the new configuration syntax in depth. This book isn’t intended as a reference manual; we deliberately chose to provide examples of working Mule configurations over tables of XML schema elements and screenshots of Mule Studio. More importantly, providing such a book would duplicate the content already available at www.mulesource.org, the Mule Javadocs, and the XSD documentation—sources from which complete reference documentation is available. We hope that reading Mule in Action gives you the skills to use these resources effectively.

Roadmap

The first part of this book will take you through a journey of discovery of the core aspects of Mule and will provide the fundamental knowledge you need to get started building integration applications with this ESB. After explaining the origin of the field of enterprise application integration, the first chapter sets the stage for the rest of the book by getting you started with your very first Mule project. Chapter 2 will make your head spin with the introduction of numerous essential concepts related to message processing in Mule, which will be referred to throughout the book. But fear not, chapter 3 will start building on this new knowledge by introducing you to transports and connectors, the basic building blocks required to start integrating systems. Chapter 4 will expand your knowledge by adding the notion of message transformation, one of the main activities performed by Mule. Going further, chapter 5 will delve into the crucial aspect of routing messages, while chapter 6 will detail how to handle these messages with components and configuration patterns.

The second part is not only focused on applying all the knowledge previously acquired but also on learning how to build and run production-grade Mule applications. With all the building blocks in hand, where does one need to start and what must be considered to succeed with Mule? These are the important questions answered in chapter 7. Chapter 8 covers the different deployment strategies supported by Mule, so you can decide on the best approach for your needs and particular environment. Chapter 9 digs into exception handling and transaction management so you can learn how to increase the reliability of your applications. Securing Mule is a must in publicly exposed applications or anytime sensitive data is processed; chapter 10 will tell you all about Mule’s security model. Finally, chapter 11 details strategies for testing and improving the performance of your applications.

The third part of the book will expand your horizon by giving you the tools and knowledge to go further with Mule. Chapter 12 will dive deep in Mule’s internal API, opening the door to complex and rich interactions with the integration framework in ways that the XML configuration alone can’t do. Chapter 13 explains in detail how DevKit, a free tool provided by MuleSoft, can be used to create custom extensions to Mule. Finally, chapter 14 presents how Mule can be made even smarter with the integration of business rules and complex event processor engines.

In order to preserve the reading flow of the book, we’ve extracted reference material in appendixes. The Mule Expression Language is detailed in appendix A, while appendix B covers Mule’s specific annotations that you can use in your custom code. Appendix C introduces the features available in the Enterprise Edition of Mule. Finally, a complete Mule application is described in appendix D.

Code conventions and downloads

The code examples in this book are abbreviated in the interest of space. In particular, namespace declarations in the XML configurations and package imports in Java classes have been omitted. The reader is encouraged to use the source code of the book when working with the examples. The line length of some of the examples exceeds that of the page width. In these cases, the or markers are used to indicate that a line has been wrapped for formatting. Code annotations highlight certain lines of code in some of the listings.

The source code of the book is available from the publisher’s website at www.manning.com/MuleinActionSecondEdition and from GitHub here: https://github.com/ddossot/mule-in-action-2e. The required configuration to run these examples is the following:

• JDK 1.6 with unlimited JCE cryptography
• Maven 3
• Mule 3.4.x Community Release

Author Online

Purchase of Mule in Action, Second Edition, includes free access to a private web forum run by Manning Publications where you can make comments about the book, ask technical questions, and receive help from the authors and from other users. To access the forum and subscribe to it, point your web browser to www.manning.com/MuleinActionSecondEdition. This page provides information on how to get on the forum once you’re registered, what kind of help is available, and the rules of conduct on the forum.

Manning’s commitment to our readers is to provide a venue where a meaningful dialog between individual readers and between readers and the authors can take place. It’s not a commitment to any specific amount of participation on the part of the authors, whose contribution to the forum remains voluntary (and unpaid). We suggest you try asking the authors some challenging questions lest their interest stray!

The Author Online forum and the archives of previous discussions will be accessible from the publisher’s website as long as the book is in print.