More than in any other Liferay release, Liferay DXP 7.0 centers on you, the developer. Liferay’s platform has been rebuilt, making it easier to build on and maintain, and providing more new developer features than any previous Liferay release.
Here are some key benefits of this release for developers:
Simpler and Leaner
Modular Development Paradigm
More extensible, easier to maintain
Optimized for your tooling of choice
Let’s consider how they make development easier for you.
Simpler and Leaner
Liferay has always been simple and lean, compared to the proprietary alternatives; this version widens the gap even more.
Liferay DXP 7.0 is simpler than its predecessors, thanks to a streamlined and modular architecture. In addition, many Liferay specific ways of creating extensions and applications have evolved to follow official or de-facto standards. As a result, developers can now more easily reuse their existing knowledge and use what they learn developing for Liferay outside of it.
Liferay DXP 7.0 is also leaner. Its modularized core allows developers and system administrators to remove parts they don’t need or don’t want; this facilitates deployment, reduces startup times and memory footprints, and results in more efficiencies and performance improvements.
Modular Development Paradigm
If you have been using Liferay, you’ve already experienced some of the benefits of modular development, thanks to plugins. Liferay DXP 7.0 takes these benefits to a whole new level.
In addition to building plugins as you have previously, you can take advantage of a complete module development and runtime system based on OSGi standards. Liferay DXP 7.0 facilitates creating applications of all types by composing and reusing modules.
And don’t worry, modules are easy to understand. A module is distributed as a JAR file and can be as small as one Java class or as large as any application you can think of. An application for Liferay can comprise one single module or as many modules as you want. The cool thing is that modules can cooperate, allowing you to build applications by combining smaller pieces that are easier to develop, deploy, maintain, and reuse.
If you have worked on large developments on top of Liferay you have probably experienced situations in which you wanted to share a subset of classes from from one plugin with another.
Java EE does not provide any standard way to achieve this, but Liferay provided certain capabilities to achieve it with a mechanism known as CLP that used class loader magic to allow plugins to invoke services in other plugins created with Service Builder. This mechanism, however, is still a bit limited (Java EE’s class loader doesn’t allow for much more) and doesn’t give you the freedom to specify any or all classes from one module to use from within another module.
Liferay DXP 7.0 enables greater reusability, both in code and runtime memory, several folds. For any desired reusable functionality you just create a module (remember, it’s just a JAR file with some metadata) with the classes you want and deploy it. Other modules need only declare that they use the classes in that module (by specifying their packages) and Liferay DXP 7.0 automatically wires them together. All invocations are regular Java calls! Try it out; it’s beautiful. :)
This mechanism eliminates the dreaded “JAR/classpath hell” issue. No longer do you have to jockey JAR files in classpaths; nor do you have to implement intricate class loaders. The runtime environment uses separate class spaces per module; it even accommodates using multiple versions of libraries in the same application (as long as they can coexist).
More Extensible, Easier to Maintain
Whenever we ask Liferay developers what is their favorite characteristic of Liferay, “Great extensibility” is one of the top three most popular responses. You can customize almost every detail and add your own functionality on top.
Is Liferay DXP 7.0 more extensible? You bet! Many more extension points have been added. But not only that, all new extension points and many existing ones which have been upgraded, use a new extension mechanism based on OSGi’s service model. Here are some of the mechanism’s benefits:
Simpler: An implementation of an extension point is now always a Java class that implements an interface and has one annotation (@Component). That’s it; it couldn’t be any easier.
Easier to maintain: Extension points are now more strictly defined through a Java interface that uses Semantic Versioning rules. This means that your extensions can work without changes, even across several Liferay versions, as long as the specific extension API is backwards compatible.
Dynamic: Extensions can be loaded and removed at any time during development or in production.
But that is not all. Your own developments can now also leverage this model and become extensible. You can create simple extension points by just creating an interface and annotating a setter method with an annotation (@Reference). Implementing extensibility has never been easier.
Optimized for Your Tooling of Choice
Liferay DXP 7.0 empowers you to use the tools you like.
If you don’t have strong preferences and are open to our suggestions, we offer Liferay Workspace. It provides an opinionated directory structure and build system based on Gradle and Bnd. Liferay Workspace can be used standalone through the command line or with Liferay Developer Studio, which runs on Eclipse.
And if you want to continue using the Plugins SDK, we’ve got you covered. The Plugins SDK is available to facilitate your transition to Liferay DXP 7.0. In fact, a Plugins SDK structure can reside in a Liferay Workspace alongside new developments that use the new build environment; you can switch between traditional projects and new projects at your own pace.
Finally, we have also developed a lightweight tool called Blade CLI, which facilitates starting new projects from templates – it’s especially useful for Gradle which doesn’t have Maven’s concept of archetypes. Blade CLI also offers commands to start/stop the server and deploy and administer modules.
Creating configurable code is a breeze with Liferay DXP 7.0. And applications that use Liferay’s new Configuration API allow administrators to change the configuration on the fly, through an auto-generated user interface called System Settings.
Now you understand how Liferay DXP 7.0 enriches your experience as a developer and makes developing apps and customizations fun.
Next, we’ll take a look at OSGi and modularity to discuss key concepts and demonstrate how easy and gratifying it is to build modules.