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Play 2.0 documentation
Play 2.0 is a high-produc tiv ity J av a and Sc ala web applic ation framework that integrates the
c omponents and APIs y ou need for modern web applic ation dev elopment.
Play is bas ed on a lightweight, s tateles s , web-friendly arc hitec ture andfeatures predic table
and minimal res ourc e c ons umption (CPU, memory , threads ) for highly -s c alable applic ations ,
thank s to its reac tiv e model, bas ed on Iteratee IO.
1. About
2. Getting started
3. Play 2.0 for Scala developers
3.1 HT T P programming
3.2 Asynchronous HT T P programming
3.3 T he template engine
3.4 HT T P form submission and validation
3.5 Working with JSON
3.6Working with XML
3.7 Handling file upload
3.8 Accessing an SQL database
3.9 Using the cache
3.10 Calling web services
3.11 Integrating with Akka
3.12 Internationalization
3.13 T he application Global object
3.14 T esting your application
3.15 Handling data streams reactively
3.16 Your first application
4. Play 2.0 for Java developers
4.1 HT T P programming
4.2 Asynchronous HT T Pprogramming
4.3 T he template engine
4.4 HT T P form submission and validation
4.5 Working with JSON
4.6 Working with XML

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4.7 Handling file upload
4.8 Accessing an SQL database
4.9 Using the cache
4.10 Calling web services
4.11 Integrating with Akka
4.12 Internationalization
4.13 T he application Globalobject
4.14 T esting your application
4.15 Your first application
5. Detailed topics
5.1 T he build system
5.2 Working with public assets
5.3 Managing database evolutions
5.4 Configuration file syntax and features
5.5 Deploying your application
6. Hacking Play 2.0

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Introducing Play 2.0
Sinc e 2007, wehav e been work ing on mak ing J av a web applic ation dev elopment eas ier. Play
s tarted as an internal projec t at Zenex ity and was heav ily influenc ed by our way of doing web
projec ts : foc us ing on dev eloper produc tiv ity , res pec ting web arc hitec ture, and us ing a fres h
approac h to pac k aging c onv entions from the s tart - break ing s o-c alled J EE bes t prac tic es
where itmade s ens e.
In 2009, we dec ided to s hare thes e ideas with the c ommunity as an open s ourc e projec t. The
immediate feedbac k was ex tremely pos itiv e and the projec t gained a lot of trac tion. Today after two y ears of ac tiv e dev elopment - Play has s ev eral v ers ions , an ac tiv e c ommunity of
4,000 people, with a growing number of applic ations running in produc tion all ov erthe globe.
Opening a projec t to the world c ertainly means more feedbac k , but it als o means dis c ov ering
and learning about new us e c as es , requiring features and un-earthing bugs that we were not
s pec ific ally c ons idered in the original des ign and its as s umptions . During the two y ears of
work on Play as an open s ourc e projec t we hav e work ed to fix this k ind of is s ues, as well as
to integrate new features to s upport a wider range of s c enarios . As the projec t has grown, we
hav e learned a lot from our c ommunity and from our own ex perienc e - us ing Play in more and
more c omplex and v aried projec ts .
Meanwhile, tec hnology and the web hav e c ontinued to ev olv e. The web has bec ome the
c entral point of all applic ations . HTML, CSS and J avaSc ript tec hnologies hav e ev olv ed
quic k ly - mak ing it almos t impos s ible for a s erv er-s ide framework to k eep up. The whole web
arc hitec ture is fas t mov ing towards real-time proc es s ing, and the emerging requirements of
today ’s projec t profiles mean SQL no longer work s as the ex c lus iv e datas tore tec hnology . At
the programming language lev el we’v e witnes s ed s...