This document compares Java and Scala for web development using the Playframework 2.5.x. It provides an overview of Scala and the Playframework, including how to set up a Play application with Scala. It demonstrates building a sample web application for a speaker database using Play and Scala, including setting up the project structure, models, database integration, JSON handling, testing, and deployment. The document aims to demonstrate how to develop a web application from start to finish using the Playframework and Scala.

1. Java or Scala – Web development
with Playframework 2.5.x?
Krešimir Dujmić
kresimir.dujmic@etna.hr

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• Lover introductory cost
– Open Source
– Doesn’t enforce expensive infrastructure(Commodity Hardware)
• Free of any vendor lock-in
• Commercial support 24x7
Open source based
Powered by

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What is Scala?
• Statically typed language on JVM
• Functional style programming - not enforced
• case classes, traits, monads, implicits, lazy val, high order
• checked exceptions gone, semicolons gone, brackets
almost gone, pattern matching

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What is PlayFramework?
• lightweight, stateless, web-friendly architecture
• make your changes and simply hit refresh! All you need
is a browser and a text editor.
• IDE support for Eclipse and IntelliJ IDEA
• support for Java or Scala

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Activator
• activator ui – in browser templates and starters
• http://127.0.0.1:8888/home

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Play application structure
• convention over configuration
• build.sbt – Scala build tool
• app folder – controllers and views
• conf folder – all configuration files
– application.conf
– logback.xml
– routes
• test folder – unit test folder
• public – static assests ( .js, images,
css)

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build.sbt

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HTTP request & responses

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conf/routes
HTTP
method
URL path Controller method

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Action, Controllers, Result
• Routes – conf/routes.xml:
• Controllers: controllers/HomeController.scala or .java

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Javantura speaker database -
model
case class Company(id: Long, name: String)
case class Speaker(id: Long,
name: String,
session: String,
registrated: Option[Date] ,
companyId: Option[Long])

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Evolutions
• H2 database & browser included
• can be any other database
• db.default.url="jdbc:h2:mem:play;MODE=MYSQL"

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Working with database
• Anorm, Slick, Ebeans
• HikariCP– JDBC connection pools

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Update example - anorm

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Working with JSON
• Automatic conversion to and from case classes with
minimal boilerplate.
• Custom validation while parsing.
• Create JSON from object:

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Testing
• Scala: integration with ScalaTest, specs2
• Java: integration with Junit
• Mockito library included
• natural languge mimicing
• Testing with a server
• Testing with a browser – Selenium WebDriver,
FluentLenium
• Integration test
• Model test
• activator test

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Javantura Speakers Test

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Installation & running
• activator dist
• standalone version of application
• ready to run zip (start.bat or BASH script included)
• only JAVA JRE is needed on server

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Javantura speakers database

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Javantura speakers database - DEMO
• Code available at:
https://github.com/kdujmic/javanturaplay
Links:
• https://playframework.com
• http://www.scalatest.org/
• https://etorreborre.github.io/specs2/
• https://www.scala-lang.org/

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Tnx!