This document outlines a presentation on Scala for Java developers. It introduces Scala, discussing its origins, key features like functional programming, object orientation, and strong static typing. It also covers development tools, frameworks, continuous integration/delivery tools, and pros and cons of adopting Scala for Java teams. The presentation agenda includes an introduction to Scala, tools, frameworks, CI/CD integration, and adopting Scala.

1. SCALA
FOR
JAVA DEVELOPERS
Java Day Istanbul 2017
BARIS DERE

2. AGENDA
• About Me
• Introduction to Scala
• Development Tools
• Scala Frameworks
• CI / CD Tools and Integration
• Adoption of Scala for Java teams
• Scala cons/pros

3. ABOUT ME
• Software Architect
• Tech Lead Java / Scala
• Online Trainer
• 15 years Java experience
• 2 years Scala experience
• Certification: OCPJEA 6, OCPJP, OCPJD, OCPWCD,
OCPJBCD, Scrum, RUP

4. INTRODUCTION TO SCALA
• Released early 2004
• Created by Martin Odersky and his team
• Scalable Language
• Functional programming
• Object Oriented programming
• Strong Static Type system
• Runs on JVM
• Compatible with Java (Java to Scala) (Scala to Java)

5. INSTALLATION & REPL
• Install Java 8
• https://www.scala-lang.org/download/
• Download and extract
• REPL (Read Evaluate Print Loop)
• Evaluate expressions
• scala – java
• scalac - javac

6. EVERYTHING IS AN OBJECT
• No operators (Operator methods)
• No primitives (Int, Long, etc)
• No arrays (object Array)

7. IMMUTABLE
• Unchangeable
• Thread safe (Concurrency friendly)
• without synchronized

8. TYPE INFERENCE
• Compiler deduces type

9. FUNCTIONS
• Functional programming
• Define functions
• Return values
• Lambdas
• Function parameters
• Infix style

10. CLASSES
• Class
• Case class
• Object
• Trait

11. IMPLICITS
• Parameters
• Conversions
• Methods

12. PATTERN MATCHING
• It allows to match on any sort of data with a first-match
policy
• case class support

13. OPTION / SOME / NONE
• No null pointer exceptions
• Support for optional values

14. DEVELOPMENT TOOLS
• IntelliJ (JetBrains Scala Plugin)
• Scala IDE for Eclipse (http://scala-ide.org )
• Netbeans IDE with Scala Plugin
• SBT (Simple Build Tool) (Maven)

15. SCALA FRAMEWORKS /
TOOLS
• Testing
• ScalaTest
• Specs2
• ScalaCheck
• Database
• Slick
• Web
• Play Framework
• Finatra
• Scalatra
• Scala.js

16. CREATED WITH SCALA
• Apache Kafka
• Apacke Spark
• Akka
• https://github.com/lauris/awesome-scala

17. CI/CD TOOLS & INTEGRATION
• Jenkins
• Apache Maven (scala-maven-plugin)
• http://docs.scala-lang.org/tutorials/scala-with-maven.html

18. PROS & CONS
• Pros
• Runs on JVM & Use Java libraries
• OO & Functional Programming
• Higher productivity (Fun)
• Higher quality
• Cons
• Learning curve
• Slow compile
• More things to do
• Implicit, type inference, macro expansion, etc
• Limited backward compatibility

19. JAVA TO SCALA
• Training
• Functional Programming
• Learning curve
• Multi module projects
• Step by step refactoring