Slide 1
Slide 1 text
Spring 5 Themes & Trends
Stéphane Nicoll - @snicoll
Slide 2
Slide 2 text
Last 4.x feature release: 4.3
2
• Released on June 2016
• Extended support life until 2019
• on JDK 6, 7, 8
• on Tomcat 6, 7, 8.0, 8.5
• on WebSphere 7, 8.0, 8.5 and 9
• Programming model refinements brought forward to JDK 6+
• DI & MVC refinements
• Composed annotations
Slide 3
Slide 3 text
A new framework generation for 2017+
3
• 5.0 GA available
• Spring Boot 2.0 M5 next week!
• Major baseline upgrade
• JDK 8+ and JavaEE 7 (Servlet 3.1+, Bean Validation 1.1, JMS 2.0+, JPA 2.1+)
• Support of JUnit 5 (next to JUnit 4.12)
• Comprehensive integration with JavaEE 8 API level
• Servlet 4.0, Bean Validation 2.0, JPA 2.2, JSON Binding API 1.0
• e.g. Tomcat 9.0, Hibernate Validator 6.0, Apache Johnzon 1.1
Slide 4
Slide 4 text
@snicoll
4
JDK 9
Slide 5
Slide 5 text
@snicoll
5
HTTP/2
Slide 6
Slide 6 text
@snicoll
6
Reactive Spring
Slide 7
Slide 7 text
7
∞
Slide 8
Slide 8 text
8
Going Reactive:
More for scalability and stability than for speed
Slide 9
Slide 9 text
Blocking + Thread pools
9
HTTP request
HTTP response
⏳
⚙
⏳
✍
⏳
Thread
Slide 10
Slide 10 text
Non-blocking and event-loop
10
IO Selector Thread Worker Threads
⚙ ⚙ ✍
✍ ⚙
⚙
✍ ✍ ⚙
⚙ ✍
Slide 11
Slide 11 text
11
From blocking to event-based
Neutral to latency
Slide 12
Slide 12 text
Imperative style
12
public interface PersonRepository {
Person findById(String id);
List findAll();
void save(Person person);
}
try {
Person p = personRepository.findById(id);
// ...
handle(p);
}
catch (IOException ex) {
// ...
}
Blocking
Slide 13
Slide 13 text
Functional style
13
personRepository.findById(id)
.map(this::handle)
.subscribe();
public interface PersonRepository {
Mono findById(String id);
Flux findAll();
Mono save(Person person);
}
Neutral to latency
(event based)
Slide 14
Slide 14 text
Reactive Streams
14
Publisher Subscriber
subscribe
request(n)
Backpressure
Error|Complete
onNext(data)
onNext(data)
onNext(data)
Slide 15
Slide 15 text
Reactive Streams API
15
public interface Publisher {
void subscribe(Subscriber s);
}
public interface Subscriber {
void onSubscribe(Subscription s);
void onNext(T t);
void onError(Throwable t);
void onComplete();
}
public interface Subscription {
void request(long n);
void cancel();
}
public interface Processor extends Subscriber, Publisher {
}
Slide 16
Slide 16 text
Functional style
16
personRepository.findById(id)
.map(this::handle)
.subscribe();
public interface PersonRepository {
Mono findById(String id);
findAll();
Mono save(Person person);
}
Neutral to latency
(event based)
Flux
Slide 17
Slide 17 text
17
is a Publisher for 0..n elements
Flux
Slide 18
Slide 18 text
18
Mono is a Publisher for 0..1 element
Slide 19
Slide 19 text
@snicoll
Demo
Slide 20
Slide 20 text
20
Slide 21
Slide 21 text
Reactive Web Controller
21
@GetMapping("/users/{id}")
Mono getById(@PathVariable String id) {
return this.userRepository.findOne(id);
}
@GetMapping("/users")
Flux all() {
return this.userRepository.findAll();
}
@PostMapping("/users")
Mono save(@RequestBody Mono user) {
return this.userRepository.save(user).then();
}
Slide 22
Slide 22 text
New Web Client API
22
WebClient client = WebClient.create();
Mono githubUser = client
.get()
.uri("https://api.github.com/users/{username}", username)
.retrieve()
.bodyToMono(GithubUser.class);
Mono twitterUser = client
.get()
.uri("https://api.twitter.com/1.1/users/show.json?screen_name={username}", username)
.retrieve()
.bodyToMono(TwitterUser.class);
return githubUser.and(twitterUser, (github, twitter)-> new AppUser(github, twitter));
Slide 23
Slide 23 text
23
@Controller, @RequestMapping
Spring MVC
Servlet API
Servlet Container
Spring WebFlux.fn
Servlet 3.1, Netty, Undertow
Spring WebFlux
HTTP / Reactive Streams
Slide 24
Slide 24 text
@snicoll
24
Functional APIs
Slide 25
Slide 25 text
Functional bean registration API (work in progress)
25
• Alternative mechanism to configure the ApplicationContext
• Full control over beans registration
public static void main(String[] args) {
GenericApplicationContext ctx = new GenericApplicationContext();
ctx.registerBean(A.class);
ctx.registerBean(B.class, () -> new B(ctx.getBean(A.class)));
ctx.refresh();
}
Slide 26
Slide 26 text
Functional-style web routing
26
RouterFunction route =
route(GET("/users"),
)
.and(route(GET("/users/{id}"),
)
.and(route(POST("/users"),
)));
request -> {
Flux people = repository.findAll();
return ServerResponse.ok().body(people, User.class);
}
request -> {
String personId = request.pathVariable("id");
Mono person = repository.findById(personId);
return ServerResponse.ok().body(person, User.class);
}
request -> {
Mono user = request.bodyToMono(User.class);
return ServerResponse.ok().build(repository.saveAll(user).then());
}
Slide 27
Slide 27 text
Functional-style web routing
27
RouterFunction route =
route(GET(“/users"), )
.and(route(GET(“/users/{id}”), )
.and(route(POST(“/users”), )));
this::findAll
this::findById
this::save
Slide 28
Slide 28 text
@snicoll
28
Kotlin Support
Slide 29
Slide 29 text
Type inference
29
@RestController
class UserController(val repo: UserRepository) {
@GetMapping("/user/{id}")
fun findOne(@PathVariable id: String): Mono {
}
@GetMapping("/user")
fun findAll() : Flux {
}
}
return repo.findOne(id)
return repo.findAll()
Slide 30
Slide 30 text
Type inference
30
@RestController
class UserController(val repo: UserRepository) {
@GetMapping("/user/{id}")
fun findOne(@PathVariable id: String) =
@GetMapping("/user")
fun findAll() : Flux =
}
repo.findOne(id)
repo.findAll()
Slide 31
Slide 31 text
Extensions
31
fun findAll(request: ServerRequest): Mono {
}
inline fun ServerResponse.BodyBuilder
.body(publisher: Publisher) = body(publisher, T::class.java)
ServerResponseExtensions provided by spring-webflux
return ok().body(repo.findAll(), User::class.java)
Slide 32
Slide 32 text
Extensions
32
fun findAll(request: ServerRequest) =
inline fun ServerResponse.BodyBuilder
.body(publisher: Publisher) = body(publisher, T::class.java)
ServerResponseExtensions provided by spring-webflux
ok().body(repo.findAll())
Slide 33
Slide 33 text
Leverage Kotlin nullable information
33
@GetMapping("/foo")
fun foo(@RequestParam( ) bar: String?) = …
http://localhost:8080/foo
required = false
Slide 34
Slide 34 text
Leverage Kotlin nullable information
34
@GetMapping("/foo")
fun foo(@RequestParam bar: String?) = …
http://localhost:8080/foo
Slide 35
Slide 35 text
Custom DSL
35
nest( ),
route( .
andRoute( ).
andNest( ),
.
. );
path("/blog").and(accept(TEXT_HTML)
GET("/"), blogHandler::findAllView)
GET("/{slug}"), blogHandler::findOneView)
path("/api/blog").and(accept(APPLICATION_JSON)
route(GET("/"), blogHandler::findAll)
andRoute(GET("/{id}"), blogHandler::findOne)
andRoute(POST("/"), blogHandler::create)
Slide 36
Slide 36 text
Custom DSL
36
router {
( ).nest {
}
( ).nest {
}
}
"/blog" and accept(TEXT_HTML)
GET("/", blogHandler::findAllView)
GET("/{slug}", blogHandler::findOneView)
"/api/blog" and accept(APPLICATION_JSON)
GET("/", blogHandler::findAll)
GET("/{id}", blogHandler::findOne)
POST("/", blogHandler::create)
Slide 37
Slide 37 text
And many more…
37
https://goo.gl/gMnhxN
Slide 38
Slide 38 text
@snicoll
Demo
Slide 39
Slide 39 text
Try it today: start.spring.io
39
Slide 40
Slide 40 text
40
Thank You!
@snicoll