Spring Framework 5 review of new core features.

1. SPRING FRAMEWORK 5
Aliaksei Zhynhiarouski
Ciklum, 3.2017

2. AGENDA
TIME TO LEARN MORE
▸ What awaits us with Spring 5?
▸ “Enterprise” challenges and Reactive changes
▸ Coding!

3. HISTORY
Started at 2002 by Rod Johnson & Juergen Hoeller
Company behind: Interface21, SpringSource, Pivotal

4. 2017
SPRING FRAMEWORK 4.3
Last release in 4.3 branch
support until 2019
will work with JDK 6,7,8,9
and Tomcat 6-9
Spring Framework 5 M5
Reactor 3

5. WHAT’S NEW
SPRING FRAMEWORK 5.0
Roadmap
‣ 5.0 M5 available now
‣ 5.0 RC1: April 2017
‣ 5.0 GA expected at in June (wait for JDK9 GA)
JDK 8+, Servlet 3.1+, JMS 2.0+, JPA 2.1+, JUnit 5
Major baseline updates with Java EE 7

6. WHAT’S NEW
SPRING FRAMEWORK 5.0
Core updates
‣ Java 8 in the core
‣ Java 9 full compatibility, jigsaw
Web & Infrastructure
‣ HTTP/2 on client and server HTTP/2 Comes to Java
‣ Functional vs Annotation style
‣ Lambda oriented HTTP routing & processing
‣ spring-webflux
‣ Kotlin
SPR-13716

7. WHAT’S NEW
JDK9
‣ Many general improvements
* Compact Strings, G1, etc…
‣ Spring 4.3 and 5.0 can run on JDK9
‣ Frameworks jar’s as Jigsaw-compliant modules on module path
* Application module-info.java may refer framework modules

8. WHAT’S NEW
HTTP/2
‣ Servlet 4.0 – September 2017
* enforce support for HTTP/2 in Servlet containers
* API for stream prioritization and push resources
‣ Tomcat/Jetty/Undertow
* native HTTP/2 since in current Servlet 3.1
* Tomcat 8.5/9.0, Jetty 9.3, Undertow 1.3/1.4
‣ Spring Framework 5.1 will support Servlet 4.0
* as well as support for new JDK HTTP client
* 5.0 focus on native HTTP/2 on top of Tomcat, Jetty, Undertow

9. WHAT’S NEW
FUNCTIONAL STYLE
‣ Spring 4.3 summarize annotation history
* annotation based component model
‣ Spring 5 provides functional style API as an alternative
* pragmatic bean registration and endpoint composition
* no need for annotations or scanning
‣ Even better with Kotlin
* Java 8 style is nice
* Spring Kotlin’s extension make code even more concise

10. JAVA
KOTLIN

11. ENTERPRISE CHALLENGES
DO WE NEED TO CHANGE?
“Enterprise” challenges and Reactive changes
II

12. ENTERPRISE CHALLENGES
BLOCKING IO
LATENCY REAL MATTERS
RESOURCE UTILIZATION
IMPERATIVE CODE

13. SERVLET CONTAINER IN NUTSHELL

14. SERVLET CONTAINER IN NUTSHELL

15. FIX SERVLET CONTAINERS

16. THERE IS ANOTHER WAY

17. REACTOR/EVENT-LOOP

18. REACTOR/EVENT-LOOP

19. CURRENT STATE AND CHALLENGES
NON-BLOCKING IO
LATENCY REAL MATTERS
RESOURCE UTILIZATION
REACTIVE CODE

20. REACTIVEX CRASH COURSE
Stream Abstraction
▸ Functional, declarative programming model
▸ Combine, transform, reduce sequences
▸ Focus on what, not how
Stream (JDK8)
▸ Efficiently process collections
▸ Pull based and usable only once
▸ For non latency or infinite
Reactive Library
▸ Stream(JDK8) like API
▸ Push based
▸ Latency sensitive and infinite seqs

21. Flux.fromIterable(Arrays.asList("foo", "bar", "foo"))
.map(String::toUpperCase)
.flatMap(s -> Flux.just(s.concat("!")))
.distinct()
.publishOn(Schedulers.elastic());
RX

22. HOW TO WRITE NON BLOCKING
REACTIVE STREAMS
▸ Specification for non-blocking libs interoperability
▸ Collaborative effort: Netflix, Pivotal, RedHat, Twitter,
Lightbend
▸ JDK9 adoption java.util.concurrent.Flow
▸ Only 4 Interfaces
http://www.reactive-streams.org
https://spring.io/blog/2016/04/19/understanding-reactive-types

23. REACTOR 3: REACTIVE STREAMS WITH BACKPRESSURE

24. FLUX<T>

25. MONO<T>

26. SPRING 5
SPRING + REACTOR + RX = 🌞

28. UNDER THE HOOD

29. REACTIVE STREAMS EVERYWHERE

30. REACTIVE STREAMS EVERYWHERE

31. JAVA PROFESSIONALS BY

32. LINKS
Aliaksei Zhynhiarouski
twitter: @a_lithium
http://www.reactive-streams.org
https://spring.io/blog/2016/04/19/understanding-reactive-types
Notes on Reactive Programming Part I
Notes on Reactive Programming Part II
Notes on Reactive Programming Part III
https://github.com/aliaksei-lithium/spring5demo