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Spring Dynamic Modules In Action 63

RickJWagner writes "Every once in a while a technical book comes out that so exhaustively covers a topic that it becomes the definitive word on the topic. These books are the end-all reference, the final authority, the singular go-to reference that every practitioner falls back to in their hour of need. This book review covers one such book, the newly released Spring Dynamic Modules in Action from Manning." Read below for the rest of Rick's review.
Spring Dynamic Modules In Action
author Arnaud Cogoluegnes, Thierry Templier, Andy Piper
pages 548
publisher Manning Publications
rating 9/10
reviewer Rick J Wagner
ISBN 1935182307
summary Presents the fundamental concepts of OSGi-based apps and maps them to the familiar ideas of the Spring framework.
First, a quick word about OSGi. OSGi is a specification meant to make Java more "modular." In practice, this means it is an attempt to solve the age-old problem of "jar hell", including all the class loading issues that go with it. (Users of JEE application servers know what I'm talking about here.) OSGi lets you specify every external library your component needs, to the version. So if you need FooLib v1.2.3, and the application beside yours needs FooLib v10.9.8, that's not a problem at all-- both applications can happily run in the same OSGi container, at the same time.

Should you care about OSGi? The answer is maybe. It's without question a big deal to the makers of Java application containers-- everybody from JBoss to Mule has an opinion on OSGi, and many vendors are busy baking it into their infrastructure. What will differ to you, the user of the container, is how the container developers decided to make OSGi available to their users. This book is about how Spring went about it, and what you need to do to use Spring and OSGi together.

Spring DM (short for "Dynamic Modules") is a framework that enables you to use the popular Spring framework with OSGi. Spring, of course, comes with a multitude of components for solving all kinds of enterprise application needs. So this book is all about using Spring with OSGi.

It's a big book, over 500 pages, written by 3 authors. In those 500 pages you get lots of valuable content:
- An introduction to OSGi and an explanation of its purpose
- Explanation of how Spring can be used within an OSGi container, review of the currently available containers
- Details about how Spring DM works, and the parts you need to understand
- Details about OSGi services, and how they relate to Spring DM
- In depth best practices for data access, enterprise Java projects, and web applications (includes specific advice for popular web application frameworks)
- Testing practices
- Extended uses of OSGi, including likely future direction

A big part of what makes this book valuable are the many pieces of advice from the authors as they explain best practices for using various tools. So you want to use Eclipse, Ant or Maven? No problem, these are all covered. About to use MyFaces, Wicket, or DWR? All covered. Are you a Tomcat user or Jetty? Check and check. I'm sure you get the picture-- if you use these tools, the path ahead of you is already blazed and you can avoid some headaches by leveraging the author's experience.

Make no mistake about it, there will be some headaches ahead of you. Seldom is an application written today that doesn't use an external framework or library of some sort. Using these pre-packaged bits of functionality (and we need to be thankful for them!) might mean 're-packaging', if the library isn't offered as an OSGi bundle. This re-packaging means pealing apart some .jar files and editing the manifest files inside-- yuck! Luckily, this book offers you two things to help you with this task: tooling and advice. Tooling comes in handy because it can automate a lot of the manual, error-prone drudgery that goes along with such a task. Advice is even more valuable-- these authors have already worked done the hard work and have written down what you need to do to make your efforts successful.

So who is this book appropriate for? I'd say anyone who is going to use Spring DM. If you're convinced this is the right framework for your needs, you need a copy of this book. If you're not sure, or if you're just a casual reader wanting to know more about OSGi-- then I'd say you should look through the book first before you buy it. You might like it, or you might not because a lot of the book is all about hands-on use of Spring DM and the little tricks you need to make it work right the first time. But if you're just interested in an overview of the technology, this book might be too detail-oriented and not enough high-level for your tastes.

If you use Spring DM, you need to buy a copy of this book. It's going to be the definitive resource on the topic for a long time.

You can purchase Spring Dynamic Modules In Action from amazon.com. Slashdot welcomes readers' book reviews -- to see your own review here, read the book review guidelines, then visit the submission page.


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Spring Dynamic Modules In Action

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  • Drat! (Score:5, Insightful)

    by SharpFang ( 651121 ) on Wednesday November 24, 2010 @03:38PM (#34335718) Homepage Journal

    And I really hoped for an ultimate guide to building spring-loaded mechanical toys and devices in a modular way.
    Building complex mechanisms that don't use electricity seems to be a dying art and we could really use some modern reference...

  • by Desler ( 1608317 ) on Wednesday November 24, 2010 @05:00PM (#34336622)

    Java is the new COBOL. Get over it.

  • What am I missing? (Score:4, Insightful)

    by eison ( 56778 ) <(pkteison) (at) (hotmail.com)> on Wednesday November 24, 2010 @05:02PM (#34336632) Homepage

    From the article summary, this is a *500* page book on the topic of using an app framework with a packaging system.
    How can that topic take 500 pages? It sounds like it should be a 2 page FAQ? What does a packaging system change so much that it needs 498 more pages?

  • by RichMan ( 8097 ) on Wednesday November 24, 2010 @05:08PM (#34336718)

    And if the app framework and packaging system really need 500 pages to describe how to use do you really want to use them?

  • by PJ6 ( 1151747 ) on Wednesday November 24, 2010 @05:31PM (#34336962)

    It has been my experience that frameworks such as these frequently make trivial exercises nontrivial, for the sake of implementing an idea or serving a need in a way that most would call ill-conceived, bloated, far out of the realm of sanity. How much information in this book would anyone call timeless truth? How much is instead incidental complexity, gotchas, meaningless detail, and syntax of usage? In software, beware the pursuit of an academic objective for its own sake without any regard to practicality or usability.

    A simple design that can achieve great complexity, that's beauty; a greatly complex design that can achieve only simple behavior, that's humor.

  • by Kyont ( 145761 ) on Wednesday November 24, 2010 @05:49PM (#34337160)

    I still program in COBOL, you insensitive clod!

  • Re:Better solution (Score:4, Insightful)

    by abigor ( 540274 ) on Wednesday November 24, 2010 @07:20PM (#34337926)

    Meanwhile, back in the real world, Spring, Hibernate, etc. are awesome and heavily used to prevent the kind of wheel reinvention you no doubt excel at.

  • by Anonymous Coward on Wednesday November 24, 2010 @09:05PM (#34338676)

    No offense, but you sound like somebody with no real-world experience.

  • Re:Better solution (Score:3, Insightful)

    by Lunix Nutcase ( 1092239 ) on Thursday November 25, 2010 @12:11AM (#34339506)

    Yes, so awesome that you need another framework on top of them just to manage all the dependencies. Brilliant!!

  • by secondsun ( 195377 ) <secondsun@gmail.com> on Thursday November 25, 2010 @03:15PM (#34344436) Journal

    I happen to be someone who actually likes Spring. A few months ago, I was asked to do a proof of concept project; it was basically a event organizing system with a plug-in architecture.

    A little google fu later and I found out Eclipse used OSGi for its plug in systems, Netbeans was going to support OSGi for their plugins, and Spring had an OSGi container solution called Spring DM AND Manning had this book in MEAP. I downloaded the earliest copy, ran through the "Hello World!"s and was on my way.

    Then I actually had to implement OSGi. Packages wouldn't load, they would load in the wrong order, jars weren't OSGi aware, etc etc etc. After two weeks of long nights of frustration I gave up. The next morning I wrote a classloader and was up and running in about 2 hours.

    To add insult to injury, SpringSource gave Spring DM to the Eclipse foundation and washed their hands of future development.

    TL;DR; If you want to use OSGi + Spring DM: Don't, Spring gave DM to Eclipse and OSGi is a shitstorm waiting to rain itself out. Write your own classloader and in two hours and 200 lines of Java you will have 80% of OSGi and 99% of what you care about.

A committee is a group that keeps the minutes and loses hours. -- Milton Berle