Play Framework Introduction
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The Play Framework is a full stack web framework for Java and Scala, designed for fast development with a focus on productivity, allowing for hot reloading, type safety, and a stateless architecture. It features asynchronous processing and a modular approach, enabling developers to choose their preferred tools and frameworks without enforcing opinions. Play supports various development processes, from debugging to deployment, and is backed by a vibrant community and active support for future versions.
![> 14 000 questions on Stack Overflow tagged [playframwork]](https://image.slidesharecdn.com/playframeworkintroduction-170525114354/85/Play-Framework-Introduction-23-320.jpg?cb=1732920444)
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Variable extraction (:id)
Dynamic parts spanning several / (path*)
Regular expressions ($name<[a-z]>.js)](https://image.slidesharecdn.com/playframeworkintroduction-170525114354/85/Play-Framework-Introduction-73-320.jpg?cb=1732920444)
Play Framework Introduction
- 1. The High Velocity Web Framework For Java and Scala
- 2. The High Velocity Web Framework For Java and Scala
- 3. Myself https://github.com/mkurz Using Play since 2010 (v1.1) Official collaborator (“integrator”) since June 2015 Self-employed
- 4. You are a developer using Java to build web services
- 7. What is Play? Full stack java web framework - Open Source! Based on a non-blocking architecture Lots of built in features for fast development Written in Scala and Java Extendable by modules
- 8. Play is developer friendly Strong focus on productivity. Fast turnaround. No (=very short) compile time and restart cycle Hot reloading: Fix the bug and hit reload!
- 9. Play is developer friendly
- 10. Play is developer friendly Type safe all the way, even templates and route files! Use Scala or Java: Your choice. You can even mix them! All Java 8 goodness (lambdas, streams, etc.)
- 11. Play is stateless Lightweight, asynchronous Share nothing system - no state on the server! Uses a signed cookie to save “state” on the client Concurrent and highly scalable
- 12. Play thread model Play doesn’t tie a request to a thread Play doesn’t tie a HTTP session to memory Play is non-blocking Per default Play just uses only handful threads (1 per CPU + 1) Event driven (netty/akka) - Thread is only occupied if there is something to do http://www.reactivemanifesto.org
- 13. Play is full stack Template engine (called “twirl”, a bit of scala syntax but not too bad) Websocket support Create REST APIs JSON support assets compiler (CoffeScript, LESS, SASS, TypeScript,...) -> assets pipeline No servlet support -> Built on netty / akka(-http)
- 14. Play is full stack Form handling (extracting data, validation, formatting, file uploads,...) Persistence: JPA, Ebean, JOOQ, ... Plus: filters, i18n, WS support, and much more Secure Write JUnit and integration tests
- 15. History Started as internal project by a french company, written in pure Java Play 1.0 in October 2009 Play 1.2 in April 2011 Play 2 is completely rewritten from scratch, mainly in Scala Released in March 2012 2007 2012
- 16. Backed by Lightbend, Inc.
- 17. Backed by Lightbend, Inc. A couple of full-time devs working on it $$$ Commercial support available $$$
- 18. Today Latest version: New major version coming soon: Awesome!
- 19. Who uses Play Framework?
- 21. GitHub Get involved via GitHub!
- 22. Very active mailing list - 14 000 members!
- 23. > 14 000 questions on Stack Overflow tagged [playframwork]
- 24. 1 600 people joined the conversation already That’s me!
- 25. Many high quality modules available (decentralised)
- 27. blogs about Play ;)
- 28. open sourced their whole website! (But in Scala)
- 29. Books
- 30. Great documentation with code snippets and migration guides
- 32. What do I need?
- 33. What do I need?
- 34. `sbt help`
- 35. Create a project
- 36. Create a project
- 37. Create a project
- 38. Create a project
- 39. Create a project You can create your own seed projects. They are just git repos.
- 40. Create a project (Downloading all dependencies can take a while on first run)
- 41. Play uses Ivy
- 42. Play uses Ivy You can add repositories via build.sbt
- 44. Run the project
- 45. Run the project
- 46. Run the project
- 47. Run the project
- 48. Run the project
- 50. Lets make a change
- 51. Now, restart the server.
- 52. Nah, just kidding. (We have real work to do)
- 53. Nah, just kidding. (We have real work to do) No restart Required!
- 54. Hit F5
- 55. Opens JPDA debug port which you can attach to in the IDE Debugging
- 56. Check the Play documentation how to set up the IDEs IDE support
- 57. Eclipse
- 58. Eclipse
- 60. Before I continue... Play is designed modular It’s not opinionated E.g. JPA is just one option You can use Ebean ORM, jOOQ,... You can enable just the stuff you need
- 61. The Play application layout
- 62. The Play application layout
- 65. The Play application layout
- 66. build.sbt
- 67. build.sbt ehcache, javaWs, openId, guice, ...
- 68. The Play application layout logback.xml -> Configure logging
- 70. (P/B)RO TIP! Search for reference.conf
- 71. The Play application layout
- 72. conf/routes
- 73. conf/routes Variable extraction (:id) Dynamic parts spanning several / (path*) Regular expressions ($name<[a-z]>.js)
- 74. conf/routes route files get transformed into *.scala files. scala files will be compiled into bytecode.
- 77. app/views/customer.scala.html We call another view: views/html/main.scala.html
- 78. app/views/customer.scala.html view files get transformed into *.scala files. scala files will be compiled into bytecode. So views are just functions -> `@main` is a scala function
- 79. Various extensions supported myview.scala.html -> views.html.myview.render(...) myview.scala.js -> views.js.myview.render(...) myview.scala.xml -> views.xml.myview.render(...) myview.scala.txt -> views.txt.myview.render(...)
- 80. The Play application layout
- 81. The Play application layout
- 82. The Play application layout
- 83. The Play application layout
- 84. Track your db schema changes Evolutions FTW Up (create, insert,...) /Down (drop, delete,...) sections Can be enabled/disabled per database Interactive for DEV, command line in PROD mode 1.sql, 2.sql, 3.sql, etc.
- 86. When you hit refresh
- 87. Form handling & DI
- 88. PetForm.java
- 91. Reverse routes In views: In controllers: Even in JavaScript:
- 92. Handle the form in the action (Comment after the talk: This is a bad example because this code would block because of db access. The code should actually run in another “threadpool”)
- 93. Play uses Dependency Injection
- 94. Dependency Injection in Play guice is the default but replaceable Just inject any components you need in the controller or the view That’s how the module system in Play works
- 95. Dynamic forms
- 96. Displaying errors in views Form helpers (@form.input(...) etc.) handle this for you already Checkout “play-bootstrap” module on GitHub -> It’s awesome!
- 97. Asynchronous action We don’t block when waiting for I/O
- 98. A few words on security Session cookie is signed but not encrypted Play 2.6: SameSite cookie attribute enabled for session cookie by default Built-in filters can be used: CORS, CSRFFilter (POST), SecurityHeadersFilter (CSP, ...), AllowedHostsFilter Templates escape by default (XSS)
- 99. A few words on security Authentication & authorization modules available: deadbolt, SecureSocial, ... Play security vulnerability mailing list
- 100. Let’s go into production
- 101. General notes for deploying No servlet container or application server needed! (Deploying into container is supported but not recommended - do not do it!) HTTPS support built-in if needed Usually you use a proxy like nginx in front anyway
- 102. General notes for deploying During development you run Play in DEV mode In production Play runs in PROD mode
- 103. Build native packages for different systems ● Universal zip, tar.gz, xz archives (run it via ./bin/my-web-app) ● deb and rpm packages for Debian/RHEL based systems ● dmg for OSX ● msi for Windows ● docker images!
- 105. Future of Play: v3.0 Maven, Gradle support as alternative (already available via 3rd party modules) Merge Java/Scala APIs Even more type safety Completely remove global state, DI all the way (already possible in Play 2.6) Roadmap & Play 3 Implementation Plan: https://docs.google.com/document/d/11sVi1-REAIDFVHvwBrfRt1uXkBzROHQYgmcZNGJtDnA https://docs.google.com/document/d/1OejviUX5TDlRVeKg1JD9L4qh2Tn21giItmyxRXCydN0
- 106. Questions? Get in touch! m.kurz@irregular.at https://github.com/mkurz
- 107. Questions? Get in touch! m.kurz@irregular.at https://github.com/mkurz