Converting Java to Kotlin - Bring your own code

The presentation that accompanied the workshop at I Code Java '19

Transcript

1. Workshop Converting Java to Kotlin Corneil du Plessis @corneil Bring your own code.
3. Agenda • Brief overview of Kotlin • Converting Ping Pong TDD – Roman Numerals, more... • Bring your own code. • Questions and Discussions • Java Interoperability • Interesting language features
4. Kotlin Overview • Improve readability • Reduce cognitive load • Functional and Object Oriented • Immutability
5. Kotlin – Functional and Object-Oriented
6. Zoom
7. Zoom
8. Zoom
9. Zoom
10. Kotlin – Functional and Object-Oriented
11. Kotlin – Data Class
12. Kotlin - Functions
13. Kotlin – Scope functions Name Invocation It / this Lambda result or object let receiver.let {} it {} with with(receiver) {} this {} run receiver.run {} this {} apply receiver.apply {} this receiver also receiver.also {} it receiver
14. Converting code • Converting Ping Pong TDD • Strap in....
15. Converting – Add dependencies
16. Kotlin – Maven Dependencies
17. Kotlin – Maven Plugins • https://gist.github.com/corneil/fdbac43fbc2b0909ea0cb6a0d0fd146a
18. Kotlin – Maven Plugin
19. Kotlin – Maven Java Plugin configuration
20. Interesting Kotlin features – Java interoperability • @JvmName • @get:JvmName • @set:JvmName • @JvmStatic • @JvmField • @JvmOverloads • @JvmDefault • @Throws • @JvmSuppressWildcards • @JvmMultifileClass
21. Kotlin - @JvmOverloads
22. Kotlin - Destructuring Declarations
23. Kotlin – Delegated Properties • lazy • Non-Primitives. • notNull • Primitives • observable • Lambda is invoked when modified • vetoable • Lambda can prevent an update by returning false
24. Kotlin –Delegated Properties
25. Kotlin - Delegation
26. Resources • Kotlin https://kotlinlang.org/ • Kotlin Reference https://kotlinlang.org/docs/reference/ • Kotlin Playground https://play.kotlinlang.org/ • Tutorials https://kotlinlang.org/docs/tutorials/ • More https://kotlinlang.org/docs/resources.html • Awesome Kotlin https://kotlin.link/