|Stable release||2.4.2 / July 3, 2015|
|Type||Web application framework|
|License||Apache 2 License|
Play is an open source web application framework, written in Scala and Java, which follows the model–view–controller (mvc) architectural pattern. It aims to optimize developer productivity by using convention over configuration, hot code reloading and display of errors in the browser.
Support for the Scala programming language has been available since version 1.1 of the framework. In version 2.0, the framework core was rewritten in Scala. Build and deployment was migrated to SBT, and templates use Scala instead of Groovy.
Play was created by software developer Guillaume Bort, while working at Zengularity SA (formerly Zenexity). Although the early releases are no longer available online, there is evidence of Play existing as far back as May 2007. In 2007 pre-release versions of the project were available to download from Zenexity's website.
Play 1.1 was released in November 2010 after a move from Launchpad to GitHub. It included a migration from Apache MINA to JBoss Netty, Scala support, native GlassFish container, an asynchronous web services library, OAuth support, HTTPS support and other features.
Play 1.2 was released in April 2011. It included dependency management with Apache Ivy, support for WebSocket, integrated database migration (reversion is not implemented yet), a switch to the H2 database and other features.
Play 2.1 was released on February 6, 2013, upgraded to Scala 2.10 and introduced, among other new features, modularisation, a new JSON API, filters and RequireJS support.
Play 2.2 was released on September 20, 2013. Upgraded support for SBT to 0.13, better support for buffering, built in support for gzip and new stage and dist tasks with support for native packaging on several platforms such as OS X (DMG), Linux (RPM, DEB), and Windows (MSI) as well as zipfiles.
Play is heavily inspired by Ruby on Rails and Django and is similar to this family of frameworks. Play uses Java to build web applications in an environment that may be less Java Enterprise Edition-centric. Play uses no Java EE constraints. This can make Play simpler to develop compared to other Java-centric platforms.
Major differences from other Java frameworks
- Stateless: Play 2 is fully RESTful – there is no Java EE session per connection.
- Integrated unit testing: JUnit and Selenium are support is included in the core.
- API comes with most required elements built-in.
- Static methods: all controller entry points are declared as static (or equivalently, in Scala, functions on Scala objects). After requests were made for this to be customisable, Play 2.1 now supports other styles of controllers, so controllers need not be static/Scala objects; however, this is still the default.
- Asynchronous I/O: due to using JBoss Netty as its web server, Play can service long requests asynchronously rather than tying up HTTP threads doing business logic like Java EE frameworks that don't use the asynchronous support offered by Servlet 3.0.
- Modular architecture: like Ruby on Rails and Django, Play comes with the concept of modules.
- Native Scala support: Play 2 uses Scala internally, but also exposes both a Scala API, and a Java API that is deliberately slightly different to fit in with Java conventions, and Play is completely interoperable with Java.
Play 2.0 makes use of several popular Java libraries:
- JBoss Netty for the web server
- No required ORM, but Anorm (Scala) and Ebean (Java) are included for database access
- Scala for the template engine
- Built in hot-reloading
- sbt for dependency management
The following functionality is present in the core:
- a clean, RESTful framework
- CRUD: a module to simplify editing of model objects
- Secure: a module to enable simple user authentication
- a validation framework based on annotations
- a job scheduler
- a simple to use SMTP mailer
- JSON and XML parsers and marshallers
- a persistence layer based on JPA
- an embedded database for quick deployment/testing purposes
- a full embedded testing framework
- an automatic file uploads functionality
- multi-environment configuration awareness
- a modular architecture, which enables bringing new features in the core easily
- OpenID and web services clients
|This section's factual accuracy may be compromised due to out-of-date information. (March 2012)|
Play provides a built-in test framework for unit testing and functional testing. Tests are run directly in the browser by going to the URL <serverurl>/@tests. By default all testing is done against the included H2 in-memory database.
The mailing list for the project has over 11,000 subscribers. It is used in various projects such as local governments, company intranets, mobile web sites and Open Source projects.
As of October 2013[update], the Play Framework is the most popular Scala project on GitHub. In July 2015, Play was the 3rd most popular Scala library in Github, based on 64,562 Libraries. 21.3% of the top Scala projects used Play as their framework of choice.
Some notable public websites using Play:
- LinkedIn, the world's largest professional network
- Coursera, a website for online learning
- http://gendi.fr/, GENDI, a GS1 member
- http://jobs.siliconsentier.org/, jobs board of Silicon Sentier
- http://www.seine-et-marne.fr/, General council website of Seine-et-Marne, France.
- http://typesafe.com/, corporate website for Scala company founded by Martin Odersky
- http://live.gilt.com Live shopping updates featuring Play's Realtime Web features, more details on their use of Play on Gilt's technology blog
- Sync Video, service for watching online videos in sync
- Prenser, news media network
- PeachDish, food e-commerce company
- Webservice First, a customer support and ticketing system (based on play 1.2.7)
In December 2010, the first e-book for the Play framework was released. This was subsequently also published in hard copy. In August 2011, a second book was released, covering more complex and modern features.
In August 2011, Heroku announced native support for Play applications on its cloud computing platform. This follows module-based support for Play 1.0 (but not Play 2.x) on Google App Engine, and documented support on Amazon Web Services.
- Play Team (2015-07-19). "Play changelog".
- Playing with Play Framework for Java
- Nicolas Leroux at Devoxx
- guillaume bort ★ software designer
- play-framework | Google Group
- ~play-developers/play/1.0 : revision 1
- Play framework - downloads
- Play 1.1 -- Release notes
- Community Contributed Extensions
- Play 1.2 -- Release notes
- Play 2.0 -- Philosophy
- Play! Framework Usability
- Play Framework on JBoss AS 7
- Play framework and async I/O
- Play's Google Group
- "GitHub: Search stars>1". Retrieved 5 October 2013.
- "The Top 100 Scala Libraries in 2015 – Based on 64,562 GitHub Libraries>1". Retrieved 19 July 2015.
- Introducing the Play! Framework
- Play Framework Cookbook
- Play! on Heroku
- Java development 2.0: Play-ing with Amazon RDS
- Play 2 Framework on Jelastic