Play for Java
Nicolas Leroux and Sietse de Kaper
(Manning, paperback)
“There are,” co-author Nicolas Leroux writes, ” many Java web frameworks, but most of them have a key flaw: they try to hide the web behind an abstraction layer, rather than embracing it. That is the most important difference between Play and most other Java web frameworks (Servlets, we’re looking at you!).”
His writing partner, Sietse de Kaper, adds: “Play ‘gets it.’ For ‘it,’ in this case, a lot of things can be substituted. Play ‘gets’ HTTP and the web in general, how developing web application works, what makes a nice and clean API, and more. This was clear from the early Play 1 beta versions, and that’s why we’ve used it on many projects since 1.0 came out. It didn’t disappoint. Now, with Play 2, Play continues to improve web development for the Java platform.”
Their new book from Manning is nicely written, adequately illustrated and structured properly to help newcomers get started with Play and with basic web application development. Play for Java also can help experienced web app developers quickly get up to speed quickly with this powerful development platform.
You start by creating and modifying the ubiquitous “Hello world!” application. Then you spend the remaining chapters developing, expanding and enhancing a warehouse management application, one designed to meet specific requirements within a made-up company. “Enterprise applications usually live inside the IT department and are usually hosted within the organization,” Leroux and de Kaper explain. Indeed, businesses may have several or many enterprise applications serving specific purposes, and those apps often do not communicate with each other.
As both writers note: “Web developers are used to interacting with their applications through the browser. With Play, you can also use the console to interact with your web application’s development environment and build system. This is important for both quick experiments and automating things.”
The web app framework Play is, indeed, fun to play with–and work with. For example, it is very good at showing you exactly (ona browser screen) where you have made a keystroke mistake or other blunder in your code. And the words “Compilation error” on the screen display can’t be missed. Indeed, they can be read from across a room. (Fortunately, in my office, so no one sees them but me.)
If you decide to download Play and give it a try, be sure you (1) have Java installed correctly and (2) know how to set PATHs correctly on your Windows, Linux, or Mac machine. (I had a lingering Java glitch in one of my machines, and I nearly flung a Windows 7 PC into a wall in frustration. But I finally found the problem and fixed it, and Play immediately popped to life as shown in the book. Meanwhile, Play installed smoothly on a Windows 8.1 machine and an ex-XP PC now running Ubuntu.)
The authors show how to use Play with three IDEs: Eclipse, NetBeans and IntelliJ. Or, if you prefer, you can stick with the Play console and a text editor such as Notepad++ (my current favorite). And they repeatedly emphasize that (1) you should not worry that their Java framework called Play actually is written in Scala and (2) you will encounter some bits of Scala while working with template files.
“Any template language has structures you need to know to build your templates, and Scala templates are no different,” they explain. “Once you know what you have to do to, for example, iterate over a collection or insert a variable value somewhere, you know all you have to know to use that feature. You don’t have to think of it as Scala if you don’t want to. Think of it as another template language.” (Actually, Scala is not scary at all once you’ve spent a little time with it or taken an online class.)
Play supports the optional use of some compiled assets, and “[o]ut of the box, Play 2 comes with support for LESS, CoffeeScript, and Google’s Closure compiler,” the co-authors note.
According to Playframework.org, Play is built on Akka and offers “a lightweight, stateless, web-friendly architecture.” It also offers built-in testing tools and speedy “hit refresh” workflow capabilities.
Whether you are an experienced web app developer, a newcomer, a student or a hobbyist programmer, it can be serious fun to work with–or play with–Play. And Nicolas Leroux’s and Sietse de Kaper’s Play for Java can be exactly the well-tuned guide you need to learn Play 2.
— Si Dunn
