SpringBoot+ Groovy, Gorm, Gradle

Presented by: Vasu Srinivasan, Texas NIC UsaFor: Austin Groovy-Grails User Group (AGGUG), 2014-06-12

about:me Vasu Srinivasan Sr Tech Consultant at Texas NIC, USA

Twitter: @vasya10 Blog: http://vasya10.wordpress.com Slides: http://www.slideshare.net/vasya10/ Videos:

Battle of Programming Languages -https://www.youtube.com/watch?v=dKftGfU0giA Along with Eric Kelm (@asoftwareguy, asoftwareguy.com)

Current interests Grails/Groovy, AngularJS, SharePoint, Java, MongoDB, NodeJs

about:Texas NIC, USA NIC is in 29 states, specializing in e-government

scrum teams Grails, SpringBoot, Spring, Oracle SOA, SharePoint, .Net stack

major applications www.texas.gov licensing applications

driver license renewals and reinstatements concealed handgun occupational and renewal licenses

birth and death certificates vehicle inspections texas department of criminal justice - Inmates App and many many more!

our work benefits and impacts Texans directly

why-not:spring scalability has become a key issue for enterprise applications

stateless services provide better scalability

stand-alone monolithic servlet container and cluster management has in some cases become a specialized job (WebSphere anyone?) a simple http server is sufficient for many small-to-medium applications

how application is deployed, forces how to write code conceptually this will not change, but a certain level of freedom goes a long way

in maintenance and extensibility

ramp up time to create a simple starter app is pretty high many modern web frameworks have < 5 minutes to download the libraries and

create a simple application

why:spring-boot xml as a configuration – an idea’s time has passed (long ago)

obviously verbose, bloated and error-prone many post-Spring web frameworks use zero xml for configuration

Rails, Grails, Play, Wicket, etc. ramp up time is a very important criteria

Play? play install run ! Or Grails? grails create-app !

opinionated frameworks are becoming fashionable, again?

Spring had to do something to compete with fast evolving frameworks such as DropWizard, Ratpack, Sinatra, Scalatra with the concept of “micro-services architecture” (MSA)

With its vast supporting frameworks/libraries including a solid DI mechanism, it needed a simple way to tie them all

opinionated frameworks frameworks that have

strong opinions about themselves

framework by developers who have strong opinions about what goes in

why:boot spring booted xml out:

so “SpringBoot”

of course, that’s the unofficial version of the story

about:spring-boot container project for creating new Spring based applications

embedded servlet container: Tomcat or Jetty starter POMs for many libraries (web, jdbc, log, data etc) auto configurations actuators (health, metrics, beans, shutdown, ssh, etc.) xml, java annotated, groovy bean configurations

xml configuration not mandatory anymore supports many dbs via spring-data helps blend web and non-web (eg. batch) functionality supports many views

jsp (limited), thymeleaf, and groovy template engine too! (1.1.0)

using:groovy traditional Spring apps are mostly in Java, but Groovy is a

smoother, richer language

Groovy enriches Spring Boot in many ways

using:boot-with-groovyGroovy in Boot How?

Using spring-cli, run Groovy scripts

spring run app.groovybut would anyone do this in prod? not sure.

Use groovy as the language, instead of Java, the language

apply plugin: ‘groovy’compile (“org.codehaus.groovy:groovy:$groovyVersion)

Use Groovy Bean configuration instead of xml

Boot’s GroovyBeanDefinitionReader wires the beansJust like Grails resources.groovy

Use Groovy Template Engine

since Boot 1.1.0 and Groovy 2.3.2

easy to create html via markup template.templates in src/main/resources/templates/*.tplpractical in cases where html is an overkill (email templates, display history data etc.)

compile "org.codehaus.groovy:groovy-templates:${groovyVersion}"

Using Gorm Spin-off from Grailscompile("org.grails:gorm-hibernate4-spring-boot:1.0.0.GA")Annotate domain class with @Entity

using:boot-with-groovy highlights Some immediate advantages using Groovy

Practical and time-saving annotations @ToString, @Log, @EqualsAndHashCode

Faster Json conversions (with Groovy 2.3) Null-safe operations Groovy Strings Test using Spock Many classes can apply @CompileStatic and be as fast as

Java

spring-boot:demo1 Starter Project – Spring Initializer

start.spring.io add required poms, select “Gradle Project” unzip the downloaded file

Add default gradle wrapper artifacts Fix Application.groovy Add logback.groovy gradlew clean bootRun

In Mac/Linux use gvm, lazybones http://www.nautsch.net/2014/04/15/spring-boot-running-in-2-min/

spring-boot:demo1 Actuators

/beans /metrics /health /shutdown /trace /dump

Auto-configures database for HSQL DB Auto-configures a bunch of other beans Adds a default Tomcat servlet container to run on port

8080

spring-boot:demo2 Star Catalog

Simple Rest Service (Get and Post) AngularJS as client

Batch Processing Groovy Bean Configuration Groovy Template Engine as View layer

spring-boot:good-bad-and-ugly

Good, Baffling and the Unexpected

spring-boot:good traditional Spring MVC (xml) developers will

surely see advantages in reduced / manual configurations

rest made easy deployment made easy auto-configurations largely reduce initial

dependency management java annotated configurations provide type-

safety check well modularized, instead of a “kitchen-sink”

approach gradle support is awesome

spring-boot:baffling Multiple ways to setup properties

application.properties, application.yml Decide on early. Go YAML.

Too many logging frameworks are included in classpath Strongly recommend to use logback as

standard, logback.groovy works fine No out of the box support for profiles

Grails by default provides environment blocks in the configurations, making it super easy to configure for different environments

In SpringBoot, some handcraft is required to create profiles (development section in yml or application-development.properties)

Power of grailsApplication.config will be missed

spring-boot:baffling Too many @configuration related annotations

@AutoConfigure, @Configuration, @EnableConfiguration, @EnableConfigurationProperties, @ConfigurationProperties, @PropertySource, @Value

Annotations cannot be intuitively applied, reference documentation is the main guide

Too many annotations in general – sometimes I wonder what is my business logic (@Bean, @PostConstruct, @ComponentScan)

once you get past the auto-configuration magic, overriding the configurations takes a bit of discovery time what to wire? what properties are required?

spring-boot:baffling what are my views?

jsp (anyone still using this???!) thymeleaf (good and clean library) groovy template engine gsp (stand-alone spin-off from grails)

where are my views? recommended path is src/main/resources/static

too deep in the IDE view IDE settings can mistake static to be a java package, resulting in undesirable refactors

(rename for eg) or use webjars for javascript jars

UI Team may like to use bower like js dependency package tools are webjars always current?

need build customizations if using bower, sass no out of box support (yet) or grails plugin like asset-pipeline (opportunity to develop!)

spring-boot:unexpected Grails Domain objects cannot be converted to

Json directly needs a custom mapper in between

Not all xml configuration enhancements translate to Groovy Bean DSL eg. <ctx:annotation-config/> works but not <batch:/>

Broke in Spring Boot 1.1.x Gorm @Transactional is broke – throws Proxy error Gorm methods are not available at startup time (Bootstrap/InitializingBean)

substitute with a manual restful controller initiated call to initialize records

spring-boot:ide tricks (IntelliJ) run the main application directly, not via gradle bootRun For debugging add VM option

-javaagent:/path/springloaded-1.2.0.RELEASE.jar -noverify then, debug the main application

sometimes port is not released (Windows) netstat –o –a –n | findstr “8080” stop-process $id

Associate groovy template .tpl files with “Groovy” for auto-formatting

spring-boot:nice-to-have faster creation of project templates, instead of browser groovy configuration support (like .properties, .yaml)

richer runtime evaluations, environment block support out of the box support for common active profiles expose entities as Rest Entities for prototypes (like Grails

@Resource) tooling support for Groovy Bean DSL and GTE

Well, perhaps they are already in the making … ? grails-boot?

spring-boot:should we? already a heavily invested traditional Spring shop? desperately want to scale your apps now? xml configurations giving you nightmares or headaches? want a better deployment strategy? want to hop on the micro-services wagon? can’t wait for grails-boot? all of the above? any one of the above?

Links, References, Acknowledgements Spring Initializr - http://start.spring.io http://www.infoq.com/articles/microservices-intro http://docs.spring.io/spring-boot/docs/current-SNAPSHOT/reference/html

single/

Demo Application (StarCatalog) - https://github.com/vasya10/spring-boot-batch-sample

Testing SpringBoot with Spock - http://fbflex.wordpress.com/2013/09/18/testing-spring-boot-applications-with-spock/

Google Image search for cute Puss in Boots images Disney / Dreamworks for Puss in Boots images Images are used in good intention only to illustrate context of topic

Thank you!Austin Groovy/Grails User Group

ReachForce, AustinTexas NIC, Austin (Sponsor)

SpringBoot, Groovy, Grails, Gradle team!