Video and slides synchronized, mp3 and slide download available at URL http://bit.ly/25FMN17. Juergen Hoeller talks about the key themes in Spring 5, based on the current state of development: going Java 8+ across the entire framework codebase, comprehensive support for JDK 9, a strong focus on HTTP/2, and first-class support for Spring-style reactive architectures. Filmed at qconlondon.com. Juergen Hoeller is co-founder of the Spring Framework open source project and has been serving as the project lead and release manager for the core framework since 2003. He is an experienced software architect and consultant with outstanding expertise in code organization, transaction management and enterprise messaging.

1. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/1
Spring Framework 5.0
Preview & Roadmap
Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/
Juergen Hoeller
Spring Framework Lead
Pivotal

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4. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/2
On our way to 5.0
First up: 4.3

5. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/3
Spring Framework 4.3
■ Last 4.x feature release!
■ 4.3 RC1: March 2016
■ 4.3 GA: May 2016
■ Extended support life until 2020
● on JDK 6, 7, 8 and 9
● on Tomcat 6, 7, 8 and 9
● on WebSphere 7, 8.0, 8.5 and 9
■ Programming model refinements brought forward to JDK 6+
● DI & MVC refinements, composed annotations

6. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/4
The State of the Art: Component Classes
@Service
@Lazy
public class MyBookAdminService implements BookAdminService {
// @Autowired
public MyBookAdminService(AccountRepository repo) {
...
}
@Transactional
public BookUpdate updateBook(Addendum addendum) {
...
}
}

7. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/5
Configuration Classes with Autowired Constructors
@Configuration
public class MyBookAdminConfig {
private final DataSource bookAdminDataSource;
// @Autowired
public MyBookAdminService(DataSource bookAdminDataSource) {
this.bookAdminDataSource = bookAdminDataSource;
}
@Bean
public BookAdminService myBookAdminService() {
MyBookAdminService service = new MyBookAdminService();
service.setDataSource(this.bookAdminDataSource);
return service;
}
}

8. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/6
Refined MVC Controller Declarations
@Controller
@CrossOrigin
public class MyRestController {
@RequestMapping(path="/books/{id}", method=GET)
public Book findBook(@PathVariable long id) {
return this.bookAdminService.findBook(id);
}
@RequestMapping(path="/books/new", method=POST)
public void newBook(@Valid Book book) {
this.bookAdminService.storeBook(book);
}
}

9. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/7
Precomposed Annotations for MVC Controllers
@RestController
@CrossOrigin
public class MyRestController {
@GetMapping("/books/{id}")
public Book findBook(@PathVariable long id) {
return this.bookAdminService.findBook(id);
}
@PostMapping("/books/new")
public void newBook(@Valid Book book) {
this.bookAdminService.storeBook(book);
}
}

10. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/8
Themes for 5.0:
JDK 9, HTTP/2, Reactive

11. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/9
Spring Framework 5.0
■ A new framework generation for 2017+
■ 5.0 M1: mid 2016
■ 5.0 RC1: December 2016
■ Major baseline upgrade
● JDK 8+, Servlet 3.0+, JMS 2.0+, JPA 2.1+, JUnit 5
■ Key infrastructure themes
● JDK 9 and Jigsaw modules
● Servlet 4.0 and HTTP/2
● Reactive architectures

12. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/10
JDK 8+ Baseline
■ Spring 4.x: comprehensive support for Java 8 features in an application's
component classes
● Spring annotations declared as repeatable already
● typical Spring callback interfaces designed in a lambda-friendly style
● reflectively adapting to user-provided signatures
■ Spring 5.x: use of Java 8 features in the framework's own core codebase
● lambdas, method references, default methods in interfaces
● able to expose JDK 8 API types in core interfaces and classes:
java.util.Optional, java.util.function, java.util.stream
■ An important enabler for further evolution of the framework...

13. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/11
Comprehensive JDK 9 Support
■ Spring 5 schedule is close to JDK 9 schedule
● JDK 9 intends to go GA in March 2017
■ Jigsaw – a new module system for applications
● symbolic module names and requires/exports metadata for jar files
● currently no versioning, just structuring plus visibility enforcement
● module path as alternative to class path
■ New HTTP client and general support for HTTP/2
● superseding the outdated java.net.HttpURLConnection
● TLS extension for ALPN

14. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/12
Using Jigsaw with Spring
■ Spring Framework jars coming with Jigsaw metadata out of the box
● internally declaring module-info for each jar
■ Separate module namespace, following Maven Central jar naming
● spring-context, spring-jdbc, spring-webmvc
■ An application's module-info.java can then look as follows...
module my.app.db {
requires java.sql;
requires spring.jdbc;
}

15. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/13
The Importance of HTTP/2 (RFC 7540)
■ Enormous benefits over HTTP 1.1 (which dates back to 1996)
● binary protocol
● TLS (SSL) everywhere
● connection multiplexing
● headers compression
● request prioritization
● push of correlated resources
■ Browsers already implement HTTP/2 over TLS
● major websites work with HTTP/2 already: Google, Twitter, etc
● We need to embrace it in Java land as well!

16. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/14
Spring 5 and HTTP/2
■ Servlet 4.0 – mid 2017
● enforces support for HTTP/2 in Servlet containers
● API features for stream prioritization and push resources
■ Tomcat / Jetty / Undertow
● native HTTP/2 support available in current Servlet 3.1 containers
● Tomcat 8.1 / 9.0, Jetty 9.3, Undertow 1.3
■ Spring Framework 5.0 will ship dedicated Servlet 4.0 support
● as well as dedicated support for the new JDK 9 HTTP client
● but like 4.3, it focuses on native HTTP/2 on top of Tomcat / Jetty / Undertow

17. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/15
The Importance of Reactive Architectures

18. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/16
Reactive Streams Specification
■ Focus on infrastructure interoperability
● web servers, datastore drivers
● and of course: web frameworks!
■ Minimal API
● Publisher + Subscriber/Subscription for backpressure support
● repackaged into JDK 9 as java.util.concurrent.Flow
■ Operators left up to composition libraries
● map, flatMap, take, subscribe, ...
● Reactor, RxJava, Akka Streams

19. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/17
Reactive Web Endpoints in Spring
■ A Spring MVC like endpoint model based on a reactive foundation
● reusing the common Spring MVC programming model style
● but accepting and returning reactive streams
■ A new HTTP endpoint engine on top of a non-blocking runtime
● Netty, Jetty, Tomcat, Undertow
● not based on the Servlet API but adaptable to a Servlet container
■ Currently developed as a public R&D project
● https://github.com/spring-projects/spring-reactive/
● to be merged into Spring Framework master for 5.0 M1 in June

20. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/18
Reactive Web Controller with RxJava Observable
@Controller
public class MyReactiveWebController {
@RequestMapping("/capitalize")
public Observable<Person> capitalize(Observable<Person> persons) {
return persons.map(person -> {
person.setName(person.getName().toUpperCase());
return person;
}
}
}

21. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/19
Reactive Web Controller with Reactor Flux
@Controller
public class MyReactiveWebController {
@RequestMapping("/capitalize")
public Flux<Person> capitalize(Flux<Person> persons) {
return persons.map(person -> {
person.setName(person.getName().toUpperCase());
return person;
}
}
}

22. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/20
Reactive Web Controller with Repository Interop
@Controller
public class MyReactiveWebController {
@Autowired
private MyRepository<Person> repository;
@RequestMapping("/insert")
public Mono<Void> insert(Flux<Person> persons) {
return this.repository.insert(persons);
}
}

23. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/21
Reactive Infrastructure All Around
■ Reactive datastore drivers becoming available
● Postgres, Mongo, Couchbase
■ Reactive HTTP clients
● Netty, Jetty, OkHttp
■ Reactive Streams Commons project
● Servlet adapters: by default against Servlet 3.1 async I/O
● native container SPI for more efficiency at runtime
● currently a collaboration between Spring and Jetty / Tomcat

24. Unless otherwise indicated, these slides are © 2013-2016 Pivotal Software, Inc. and licensed under a
Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/22
Summary
Spring Framework 4.3 (May 2016)
Programming model refinements on JDK 6/7/8
Spring Framework 5.0 (early 2017)
JDK 8+9, Jigsaw, HTTP/2, Reactive Streams

25. Watch the video with slide synchronization on
InfoQ.com!
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framework-5