Spring Boot

What does it take to implement a Java Web Application?

Any non-Java guys in the room?

Java AppServer Libraries Build WAR

Java AppServer Libraries Build WAR #SRSLY?

Enter Spring Boot

Spring Boot Demo

Spring Boot Main @EnableAutoConfiguration @ComponentScan public class Main { public static void main(String[] args) { SpringApplication.run(Main.class, args); } }   Enable Spring Boot Configuration e.g. Web environment etc Scan for Spring annotations e.g. @Component @Configuration etc In this package and all sub packages Start application e.g. Tomcat, Spring web environment etc @SpringBootApplication = @ComponentScan+ @EnableAutoConfiguration+ @Configuration

Spring Boot: Maven pom.xml org.springframework.boot spring-boot-starter-parent 1.2.1.RELEASE org.springframework.boot spring-boot-starter-web ... Configuration inherits from parent Sets versions for dependencies Add all needed libs for a web app Many starters available

Spring Boot: Maven pom.xml ... org.springframework.boot spring-boot-maven-plugin   Makes WAR / JAR executable Support mvn spring-boot:run to run the app

Spring Boot §  Build much easier §  Supports Gradle & Ant, too §  Not limited to simple application §  Can add any other library §  Application much easier to test, debug etc §  Simple code

Let‘s add Spring Data JPA!

Spring Data JPA §  Makes implementation of repositories trivial §  Just provide an interface §  Needs JPA infrastructure of course

Spring Data JPA Repository public interface CustomerRepository extends JpaRepository { List findByName(String name); }   Defines all basic CRUD (Create, Read, Update, Delete) operations Implementation created by naming convention Add Spring Boot Starter Data JPA No further configuration Without Spring Boot or @EnableJpaRepositories("de.project")

Spring Boot + Spring Data JPA Demo

Behind the Scenes §  DataSource for HSQL created §  JPA infrastructure created §  Thymeleaf infrastructure created §  How does it work? §  Convention over configuration

Spring Boot §  Creates sensible infrastructure defaults §  i.e. DataSource if HSQL is on the classpath §  Done by *AutoConfiguration classes

Spring Boot Starter amqp aop batch data-jpa data-mongodb data-rest integration jdbc mobile redis security test web websocket actuator remote-shell jetty tomcat log4j logback data-solr data-elasticsearch data-gemfire groovy-templates freemarker thymeleaf mustache undertow velocity social-facebook social-linkedin social-twitter

Dev §  Turn Around §  Thymeleaf Templates can be changed on the fly §  …same with class files §  Spring Loaded makes reloading more powerful

Spring Boot for Dev Demo

Spring Boot for Ops

CRaSH Shell §  Ever ssh’d into your application? §  Enter CRaSH §  External library integrated into Spring Boot §  Alternative approach to operations

Spring Boot CRaSH Demo

Actuator §  Provide information about the application §  Via http / JSON §  Can be evaluated by monitoring tools etc. §  Another alternative approach to monitoring

Spring Boot Actuator Demo

Deploy §  Just package everything in an executable JAR §  …or a WAR §  Based on Maven or Gradle §  Build in configuration (YAML, properties etc.)

Spring Boot Deploy Demo

What‘s next? Spring Cloud §  Technologies for Micro Services §  E.g. Configuration §  Resilience §  Netflix stack §  Cloud Bus §  Cloud Security §  Based on Spring Boot

Conclusion §  Easy to start §  Can add libraries and features as needed §  Dev: Quick turn around §  Ops: Integrated monitoring §  Ops: Easy deployment §  Didn’t show Groovy support

Spring Boot & Microservices §  Simplifies deployment §  Standardizes Ops interface §  Simplify creating REST / web applications

Links http://start.spring.io/ http://projects.spring.io/spring-boot/ https://github.com/spring-projects/spring- boot https://github.com/ewolff/spring-boot- demos https://spring.io/guides/gs/spring-boot/ https://spring.io/guides/gs/actuator-service/ https://spring.io/guides/gs/spring-boot-cli- and-js/