What's Cool in 2015?

• JavaScript
• JavaScript
• JavaScript
• Groovy, Clojure, Scala
• F#, Swift, Go, Haskell, Ruby
• ??? Java ???

JVM Languages Help

• Groovy was Swift before Swift
• Nashorn runs JS on the JVM
• JRuby for Ruby
• Clojure, Scala, Kotlin

Java's Speed Problem

• Not app performance
• Java wins that battle (see Netflix)
• "Velocity on the JVM is the Killer App" - Andy Glover
• But speed-to-market
• Hard to jumpstart
• XML everywhere
• App Servers

Spicing up Java's Image

• Spring Boot
  • Write an app in a tweet! (so hipster)
  • Opinionated Spring all wired up
  • Production-ready by default
  • No App Server Required - executable Jars
• JHipster
  • Full stack AngularJS + Spring Boot
  • JS Build Tools
  • Beautiful Metrics
  • JHipster-loaded
• Groovy Ecosystem
  • Groovy / Spock / Gradle / gvm / Grails
• Others - Dropwizard, Akka, Vert.x

Boot Install and CLI

• 'curl -s get.gvmtool.net | bash' (for gvm)
• gvm install springboot
• A full tweet-sized 140 character app:
• spring run GBR.groovy

@RestController
  class GBR {
      @RequestMapping("/")
      String gbr() {
          "Go Big Red! #Nebrasketball"
      }
  }

Jumpstart a Real Boot App

• start.spring.io INITIALIZR
• a la carte selection menu
• IntelliJ will soon natively support

Or just 'curl start.spring.io'

Embedded Web Container

• Just run as a main class in a jar
• Great for cloud deploys. Microservices. Fat Jars.
• Weblogic, Websphere, JBoss, etc NOT REQUIRED
• gradle bootRun
• java -jar appname.jar
• Or run Main class from IDE

Or generate a War

• gradle war
• mvn package (also an executable jar file)
• Warning Disclaimer:
• Running latest of any Java stack on Websphere/Weblogic is tricky. Especially Hibernate/JPA.
• Because classloaders...
• It can be done
• Get your Google / Stackoverflow search game right

Java Config

• No XML, all Java Config (unless you like XML)

@Configuration
  @EnableAutoConfiguration
  @ComponentScan
  public class Application {
  
      public static void main(String[] args) {
          SpringApplication.run(Application.class, args);
      }
      
  }

Everything is all wired up

• No fiddling with hooking it all together
• Production-ready out of the box

Profiles

• Important piece of Spring Boot
• dev/test/prod profiles
• Available in core Spring too, but Boot leans on them

Properties

• Hierarchical properties
• application-*.properties, application.properties, System Props, JNDI Var, JVM Arg, ...

Spring Data JPA

• Simple CRUD Repositories
• (findAll, create, update, delete, and more)
• Dynamic Finders

public interface AttendeeRepository extends JpaRepository {

    List findByOrderByNameDesc();
    
    List findByNameOrderByNameAsc(String name);
    
    List findByOrderByNameAsc();
}

Spring Data REST

• Easy REST Entities
• HATEOAS enabled
• Better for quick prototypes than prod (customization)

@RepositoryRestResource(collectionResourceRel = "people", path = "people")
  public interface PersonRepository extends PagingAndSortingRepository {
  
    List findByLastName(@Param("name") String name);
    
  }

Spring MVC Spock Tests  

class AccountControllerTest extends Specification {
  def accountController = new AccountController()
  
  MockMvc mockMvc = standaloneSetup(accountController).build()
  
  def "getAccount test hits the URL and parses JSON output"() {
      when: 'rest account url is hit'
      def response = mockMvc.perform(get('/rest/account')).andReturn().response
      def content = new JsonSlurper().parseText(response.contentAsString)
      
      then: 'securityService correctly returned account in JSON'
      response.status == OK.value()
      
      //Can test the whole content string that is returned
      response.contentAsString == '{"username":"spockUser"}'
      
      //Or can use the JsonSlurper version to test the JSON as object
      content.username == 'spockUser'
  }
}

Much more

• JSP/GSP/Thymeleaf
• Metrics - app-server style
• No-SQL data stores, if that's your thing
• Great docs
• Simple tutorials

Old + New = Spring Boot

JHipster!  

• Opinionated AngularJS + Spring Boot
• Yeoman, Grunt, Bower, Gradle
• Karma Client-side tests
• Liquibase data bootstrapping
• Thymeleaf, Hazelcast, Logback, HikariCP
• Websockets with Atmosphere

Community & Branding

• It starts with an image
• Plus, the developers are amazing people
• The project is fun and positive
• Exhibit A: Response to Comic-Sans bug
• Julien Dubois @juliendubois
• Jérôme Mirc @JeromeMirc

Code Generation?

• Yeoman generates a jumpstarted app
• Also Grails-like entity generators
• Personally, I use it to build up an app structure
• At a minimum, generate an app and borrow ideas
• Can 'update' from JHipster updates, but YMMV
• vs Maven Archetypes

Slides!

• So cool they provide their own slides
• and they're much cooler than mine
• so I borrowed the next few slides from them
• Launch

JHipster Goals

• A beautiful front-end
• Latest HTML5/CSS3/JavaScript frameworks
• Latest Java/Caching/Data access technologies
• With security and performance in mind
• And great developer tooling

High Level

• Client-side
• Server-side

Generate App

npm install -g yo
npm install -g generator-jhipster
yo jhipster
gradle bootRun
grunt server

Code Walk-thru

Entity Generators

yo jhipster:entity location
//city, state, one-to-many attendee

yo jhipster:entity attendee
//name, previousAttendee, speaker, notes, many-to-one location

Show and Tell

• Change db to on-disk
• Display city, state on attendees.html list (Livereload!)
• Improve previousAttendee and speaker Y/N
• BrowserSync

JHipster-loaded

• Hot Swap almost any class
• Stop bouncing your app server
• Like JRebel but free! (as in speech AND beer)
• Extension on Spring-loaded (used by Grails)

Dev and Prod profiles

• Dev by default
• Compile or run with -Pprod to use Prod mode
• or an exectuable war:

mvn -Pprod package
java -jar jhipster-0.0.1-SNAPSHOT.war --spring.profiles.active=prod

Very Actively Developed

• 2.6.0 added full stack Validations
• 2.5 added Gatling Performance testing
• Spring Boot 1.2.2 added JMustache support

Extras

• Liquibase
• Metrics screen
• GZipping and HTTP Caching Headers
• ehcache and hazelcast
• Docker container
• Heroku and Openshift deployments

Conclusion

All good? What's not to like?

• Bloat - Downloads the whole internet
• Memory footprint is tough for free cloud deploys
• Treat container support as "beta" (my words)
• I had trouble with Websphere 8.5.5

Should I use this in my legacy application?

In your legacy app:

• Pull in pieces today
• Look at github for Spring Boot
• Generate a JHipster app and look around
• Use Spring Profiles now!
• Java Config!
• Like building Grails from scratch...

Many Many Thanks!

• Bootiful Apps talk by Josh Long
• Exploring Microframeworks by Dan Woods
• JHipster Twitter account @java_hipster