201505 Tokyo Meetup

Unless otherwise indicated, these slides are 2013-2014Pivotal Software, Inc. and licensedunder a

Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/

From Zero to Hero with Spring Boot

Stphane Nicoll Pivotal



Hello!

2 @snicoll

https://github.com/snicoll

@snicoll

[email protected]


Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/3 @snicoll


Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/4 @snicoll

Spring Boot lets you pair-program with the Spring team. Josh Long, @starbuxman



Introduction to Spring Boot

! Single point of focus (as opposed to large collection of spring-* projects) ! A tool for getting started very quickly with Spring

! Common non-functional requirements for a "real" application

! Exposes a lot of useful features by default

! Gets out of the way quickly if you want to change defaults

! An opportunity for Spring to be opinionated

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_ Spring Boot is NOT

! A prototyping tool

! Only for embedded container apps

! Sub-par Spring experience

! For Spring beginners only

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Installation

! Requirements: JDK6+ Maven 3.2+ / Gradle 1.12+

! Tools: Spring Tool Suite (STS) - IntelliJ IDEA - Netbeans Spring CLI (from https://start.spring.io or gvm)

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Lets get started!

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Getting Started Really Quickly

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@RestControllerpublic class HomeController {

@Value("${conference.name:jsug}") private String conference;

@RequestMapping("/") public String home() { return "Hello " + conference; }}



First integration test

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@RunWith(SpringJUnit4ClassRunner.class)@SpringApplicationConfiguration(classes = DemoApplication.class)@WebIntegrationTest(randomPort = true)public class HomeControllerIntegrationTest {

@Value("${local.server.port}") private int port;

@Test public void runAndInvokeHome() { String url = "http://localhost:" + port + "/"; String body = new RestTemplate() .getForObject(url, String.class); assertThat(body, is("Hello jsug")); }}



Add Spring Data JPA

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org.springframework.boot spring-boot-starter-data-jpa

com.h2database h2 runtime



Add a Speaker entity

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@Entitypublic class Speaker { @GeneratedValue @Id private Long id; private String firstName; private String lastName; private String twitter; @Column(columnDefinition = "TEXT") private String bio;

public Speaker(String firstName, String lastName, String twitter) { // initialize attributes }

// getters and setters}



Add a Speaker Repository

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public interface SpeakerRepository extends CrudRepository {

Speaker findByTwitter(String twitter);

Collection findByLastName(String lastName);}



Test that repository

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@RunWith(SpringJUnit4ClassRunner.class)@SpringApplicationConfiguration(classes = DemoApplication.class)public class SpeakerRepositoryTest {

@Autowired private SpeakerRepository speakerRepository;

@Test public void testFindByTwitter() throws Exception { Speaker stephane = speakerRepository.save( new Speaker("Stephane", "Nicoll", "snicoll")); assertThat(speakerRepository.findByTwitter("snicoll").getId(), is(stephane.getId())); }}



Add Spring Data REST

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org.springframework.boot spring-boot-starter-data-rest



RESTful repository

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public interface SpeakerRepository extends CrudRepository {

@RestResource(path = "by-twitter") Speaker findByTwitter(@Param("id") String twitter);

Collection findByLastName(@Param("name") String lastName);}



Add Spring Security

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org.springframework.boot spring-boot-starter-security



Spring Security config

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@Configurationpublic class SecurityConfig extends GlobalAuthenticationConfigurerAdapter {

@Override public void init(AuthenticationManagerBuilder auth) throws Exception { auth.inMemoryAuthentication() .withUser("hero").password("hero").roles("HERO", "USER").and() .withUser("user").password("user").roles("USER"); }}



Fix our test

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@RunWith(SpringJUnit4ClassRunner.class)@SpringApplicationConfiguration(classes = DemoApplication.class)@WebIntegrationTest(randomPort = true)public class HomeControllerIntegrationTest {

@Value("${local.server.port}") private int port;

@Test public void runAndInvokeHome() { String url = "http://localhost:" + port + "/"; String body = new TestRestTemplate("user", "user") .getForObject(url, String.class); assertThat(body, is("Hello jsug")); }}



Add Spring Boot actuator

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org.springframework.boot spring-boot-starter-actuator



Add a health indicator

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@Beanpublic HealthIndicator jsugHealthIndicator() { return () -> { if (new Random().nextBoolean()) { return Health.up().build(); } else { return Health.down().withDetail("Boooo",42).build(); } };}



Add remote shell

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org.springframework.boot spring-boot-remote-shell



Add a speaker controller

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@Controllerpublic class SpeakerController {

private final SpeakerRepository speakerRepository;

@Autowired public SpeakerController(SpeakerRepository speakerRepository) { this.speakerRepository = speakerRepository; }

@RequestMapping("/ui/speakers/{id}") public String show(@PathVariable Long id, ModelMap model) { Speaker speaker = speakerRepository.findOne(id); if (speaker == null) { throw new SpeakerNotFoundException(); } model.put("speaker", speaker); return "speakers/show"; }

@ResponseStatus(HttpStatus.NOT_FOUND) public static class SpeakerNotFoundException extends RuntimeException { }}



Create speaker show view

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View speaker

Stephane Nicoll Sample Biography. @snicoll



Best experience with PaaS

! Spring Boot features get a lot done for 12factor.net

! PaaS friendly: fast startup, devops oriented

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$ mvn package$ cf push jsug -p target/jsug-0.0.1-SNAPSHOT.jar$ cf scale jsug -i 4



Starter POMs

! standard POM / gradle files: define dependencies

! many available: batch, integration, web, ampq

! starter data-jpa = spring-data-jpa + hibernate

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org.springframework.boot spring-boot-starter-web

compile("org.springframework.boot:spring-boot-starter-web")



Writing your own starter

! Add support for X in Boot with a PR!

! Distribute a client lib in your company

! Standardize usage of component X in a platform

! [your use case here]

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Lets write our own starter!

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New auto-config project

! Create a new hello-service-auto-configuration project

! Only one mandatory dependency

! Should contain specific dependencies and auto-configuration classes

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org.springframework.boot spring-boot-autoconfigure



Add custom service interface

! This is the part that were trying to auto-configure

! In a typical use case, this interface comes from a 3rd party lib

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public interface HelloService {

String sayHello();

}



Create a default implementation

! This default implementation will be shipped with the auto-config project but should not be used if the application provides one.

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public class ConsoleHelloService implements HelloService {

public String sayHello() { System.out.println("Hello Console"); }}



Auto-configuration example

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@Configuration@ConditionalOnClass(HelloService.class)public class HelloServiceAutoConfiguration {

@ConditionalOnMissingBean @Bean public HelloService helloService() { return new ConsoleHelloService(); }

}



Declare the auto-configuration

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org.springframework.boot.autoconfigure.EnableAutoConfiguration=\demo.hello.HelloServiceAutoConfiguration

// one can order AutoConfigurations// with those annotations@AutoConfigureBefore@AutoConfigureAfter



Add a dependency to our auto-configuration

! Add our auto-config project as a dependency in our main project

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org.test.jsug hello-service-auto-configuration ...



Invoke our service when the application starts

! A Hello Service implementation is used on startup

! Running this will use the default implementation

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@Componentpublic class Startup implements CommandLineRunner { @Autowired private HelloService helloService;

@Override public void run(String... args) throws Exception { helloService.sayHello(); }}



Override default (auto-configured) implementation

! Add a @Bean definition in our DemoApplication class

! We provide our own implementation, so the default one wont be created

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@Beanpublic HelloService helloService() {

return () -> LoggerFactory.getLogger(DemoApplication.class) .info("Hello from logs"); }

}



Add type-safe properties

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@ConfigurationProperties("hello")public class HelloProperties {

private String prefix = "Hello ";

private String target;




Enable properties support

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@EnableConfigurationProperties(HelloProperties.class)@Configuration@ConditionalOnClass(HelloService.class)public class HelloServiceAutoConfiguration {



Use type-safe properties

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public class ConsoleHelloService implements HelloService {

@Autowired private HelloProperties properties;

@Override public void run(String... strings) throws Exception { System.out.println(properties.getPrefix() + " " + properties.getTarget()); }}



Generate properties meta-data

! annotation processor that generates meta-data

! uses Javadoc to build keys descriptions

! default values detected

! manual declaration allowed

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org.springframework.boot spring-boot-configuration-processor true



Document properties

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@ConfigurationProperties("hello")public class HelloProperties {

/** * Prefix of welcome message. */ private String prefix = "Hello "; /** * Target of welcome message. */ private String target;




https://spring.io powered by

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github.com/spring-io/sagan



Links

! https://projects.spring.io/spring-boot/

! https://github.com/spring-projects/spring-boot

! https://spring.io/guides

! https://spring.io/blog

! https://spring.io/questions

! https://www.youtube.com/user/SpringSourceDev

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@springboot @springcentral


Creative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/44

Learn More. Stay Connected.

! Start your project at start.spring.io

! Getting started guides

! Follow @springboot

! StackOverflow - #spring-boot

Twitter: twitter.com/springcentral

YouTube: spring.io/video

LinkedIn: spring.io/linkedin

Google Plus: spring.io/gplus

@snicoll

201505 Tokyo Meetup

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