The document discusses how Kotlin and Spring Boot are well integrated for developing applications. It provides an overview of Kotlin features like null safety and extensions, and how these improve on Java. It also discusses how Spring Boot works well with Kotlin's conventions. The document then shares details of a project to migrate a blog from XML to Markdown files using Kotlin and Spring Boot features like expression body methods and properties.

1. SPRING BOOT AND
KOTLIN, A MATCH
MADE IN HEAVEN
@NICOLAS_FRANKEL

2. SWITZERLAND
@nicolas_frankel #kotlin #springboot

3. SWITZERLAND
@nicolas_frankel #kotlin #springboot

4. SWITZERLAND
@nicolas_frankel #kotlin #springboot

5. ME, MYSELF AND I
@nicolas_frankel #kotlin #springboot
 Developer/Software -
/Solution Architect
• Java
• As consultant

6. HYBRIS, AN SAP COMPANY
@nicolas_frankel #kotlin #springboot

7. @nicolas_frankel #kotlin #springboot

8. @nicolas_frankel #kotlin #springboot

9. WHY SPRING BOOT?
@nicolas_frankel #kotlin #springboot
Convention over
configuration
• Kickstart a project in minutes,
not days
Out-of-the-box features
• Actuator

10. @nicolas_frankel #kotlin #springboot

11. KOTLIN
@nicolas_frankel #kotlin #springboot
Open Source
Compiles to
• JVM bytecode
• JavaScript (experimental)
A "simpler Scala"
@nicolas_frankel #kotlin #springboot

12. KOTLIN MAIN FEATURES
@nicolas_frankel #kotlin #springboot
Functional and object-oriented
Statically typed
Null safety
No checked exceptions
Named & optional arguments
Lambdas
Extension functions
Java compatibility
(And more...)
@nicolas_frankel #kotlin #springboot

13. KOTLIN MAIN BENEFITS
@nicolas_frankel #kotlin #springboot
More expressive than Java
Improved OO
Functional too

14. HELLO KOTLIN!
package hello // no semicolons
// namespace-level functions
// types on the right
// no special syntax for arrays
// optional return type
fun main(args: Array<String>) {
println("Hello Kotlin!")
}
@nicolas_frankel #kotlin #springboot@nicolas_frankel #kotlin #springboot

15. THE KILLER FEATURE: EXTENSIONS
@nicolas_frankel #kotlin #springboot
Extension methods
Extension properties

16. EXTENSION METHOD
@nicolas_frankel #kotlin #springboot
Add new methods on an
existing type
Called like a method on the
type
Translated to static Util
method in the bytecode

17. ENOUGH TALK…
@nicolas_frankel #kotlin #springboot

18. SPRING BOOT KOTLIN INTEGRATION
@nicolas_frankel #kotlin #springboot
Kotlin integration OOTB
Code more terse
Java configuration files less
verbose

19. ENOUGH TALK…
@nicolas_frankel #kotlin #springboot

20. MY PROJECT
@nicolas_frankel #kotlin #springboot
Migrating my WordPress
blog to Jekyll
• From one single XML export
• To a Markdown file per post

21. TYPICAL BATCH SCENARIO
@nicolas_frankel #kotlin #springboot
Read
• XML file
Transform
• Add image size
• Replace links
• Etc.
Write
• Markdown files

22. HIGHLIGHTS
@nicolas_frankel #kotlin #springboot
Expression body methods
Many one-liners into one
file
Expression properties

23. KEY TAKEAWAYS
@nicolas_frankel #kotlin #springboot

24. Q&A
@nicolas_frankel #kotlin #springboot
http://blog.frankel.ch/
@nicolas_frankel
http://frankel.in/
https://git.io/vVSLG