using groovy & grails in your spring boot project

Use Groovy & Grails in your Spring Boot projects,

don't be afraid!By Fátima Casaú

@fatimacasau

Unless otherwise indicated, these slides are © 2013-2015 Pivotal Software, Inc. and licensed under aCreative Commons Attribution-NonCommercial license: http://creativecommons.org/licenses/by-nc/3.0/ 2

@fatimacasau

Fátima Casaú Pérez

Software Engineer since 8 years ago

Java Architect & Scrum Master in Paradigma Tecnológico

Specialized in Groovy & Grails environments

Recently, Spring Boot world


What is Spring Boot?

What is Groovy?

Where could you use Groovy in your Spring Boot Projects?

● Gradle

● Tests

● Anywhere?

● Groovy Templates

● GORM

● GSP’s

Overview


Spring Boot


Standalone

Auto-configuration - CoC

No XML

Embedded Container and Database

Bootstrapping

Groovy!!

Run quickly - Spring Boot CLI

Spring Boot


Groovy


Dynamic language

Optionally typed

@TypeChecked & @CompileStatic

Java Platform

Easy & expressive syntax

Powerful features

closures, DSL, meta-programming, functional programming, scripting, ...

Groovy


Spring Boot application in a single tweet

DEMO...


First, an useful tool!


GVMGroovy enVironment

Manager Tool


GVM

Manage parallel versions

Multiple Software Development Kits

Groovy, Grails, Gradle, Spring Boot, Vert.x, Griffon,...

Unix Systems

Linux, Mac OSX, CyWin, Solaris,...

Bash

Curl & Unzip available


Actual candidates

GroovyGrailsGriffonGradleGroovyservLazybonesVert.xCrashGlideSpring BootAsciidoctorJ...

This list will grow beyond Groovy candidates.

http://groovy-lang.org/

https://grails.org/

http://griffon.codehaus.org/

http://www.gradle.org/

https://kobo.github.io/groovyserv/

https://github.com/pledbrook/lazybones

http://vertx.io/

http://www.crashub.org/

https://glide-gae.appspot.com/

http://projects.spring.io/spring-boot/

https://github.com/asciidoctor/asciidoctorj


How to use GVM and install SDK’s

To install GVM Tool

.bashrc

directory .gvm is created in home directory

$ curl -s get.gvmtool.net | bash

#THIS MUST BE AT THE END OF THE FILE FOR GVM TO WORK!!![[ -s "/home/fcasau/.gvm/bin/gvm-init.sh" ]] && source "/home/fcasau/.gvm/bin/gvm-init.sh"


How to use GVM and install SDK’s

Useful commands$ gvm help$ gvm install springboot$ gvm list springboot$ gvm install springboot 1.2.5.RELEASE$ gvm use grails 2.5.0$ gvm default groovy 2.4.0$ gvm current$ gvm current gradle$ gvm uninstall grails 2.4.4$ gvm broadcast


HelloWorld.groovy

1 @RestController2 class HelloWorld {3 4 @RequestMapping("/")5 String home(){6 "*** Hello World ***"7 }8 9 10 11 }


But... what happens

behind?


HelloWorld.groovy

1 2 3 4 5 6 7 8 @RestController9 class HelloWorld {10 11 @RequestMapping("/")12 String home(){13 "***************** Hello World *******************"14 }15 16 17 18 19 }


HelloWorld.groovy

1 @Grab(group='org.springframework.boot:spring-boot-starter-web')2 3 import org.springframework.boot.SpringApplication4 import org.springframework.web.bind.annotation.*5 import org.springframework.boot.autoconfigure.*6 7 @EnableAutoConfiguration(exclude = GroovyTemplateAutoConfiguration)8 @RestController9 class HelloWorld {10 11 @RequestMapping("/")12 String home(){13 "***************** Hello World *******************"14 }15 16 static void main(String[] args){17 SpringApplication.run HelloWorld, args18 }19 }


Executing...


Where could you use

groovy?


Gradle


Powerful build tool

Support multi-project

Dependency management (based on Apache Ivy)

Support and Integration with Maven & Ivy repositories

Based on Groovy DSL

Build by convention

Ant tasks

Gradle


Building a Spring Boot app with Gradle

DEMO...


Install Gradle and create a Spring Boot project

$ mkdir -p springOne2gx/src/main/groovy$ touch springOne2gx/src/main/groovy/Application.groovy$ cd springOne2gx$ touch build.gradle

Edit build.gradle and Application.groovy with the code of the next two slides


build.gradle

1 buildscript {2 repositories {3 maven { url "https://repo.spring.io/libs-release" }4 mavenLocal()5 mavenCentral()6 }7 dependencies {8 classpath("org.springframework.boot:spring-boot-gradle-plugin:1.2.5.RELEASE")9 }10 }11 12 apply plugin: 'groovy'13 apply plugin: 'idea'14 apply plugin: 'spring-boot'15 16 jar {17 baseName = 'springOne2GX'18 version = '0.1.0'19 }20 21 repositories {22 maven { url "https://repo.spring.io/libs-release" }23 mavenLocal()24 mavenCentral()25 }26 27 dependencies {28 compile("org.springframework.boot:spring-boot-starter-web")29 compile "org.codehaus.groovy:groovy-all:2.2.0"30 }


Application.groovy

1 import org.springframework.boot.SpringApplication2 import org.springframework.boot.autoconfigure.SpringBootApplication3 4 @SpringBootApplication5 class Application {6 7 static void main(String[] args) {8 9 SpringApplication.run Application, args10 }11 }


Executing...


Testing with Spock


Spock framework & specification

Expressive

Groovy DSL’s

Easy to read tests

Well documented

Powerful assertions

Reports

Testing with Spock


Testing with Spock

DEMO...


GoogleSpec.groovy

1 void "test Google Maps API where address is ‘Madrid’"(){2 setup: “Google Maps API Host & Uri” 3 def rest = new RESTClient("https://maps.googleapis.com")4 def uri = "/maps/api/geocode/json"5 when: “Call the API with address = ‘madrid’”6 def result = rest.get(path: uri, query: [address:'madrid'])7 then: “HttpStatus is OK, return a list of results and field status = OK”8 result9 result.status == HttpStatus.OK.value()10 !result.data.results.isEmpty()11 result.data.status == ‘OK’12 result.data.results[0].address_components.any{13 it.long_name == 'Madrid'14 }15 }


GoogleSpec.groovy

1 void "test Google Maps API with different values"(){2 setup: “Google Maps API Host & Uri”3 def rest = new RESTClient("https://maps.googleapis.com")4 def uri = "/maps/api/geocode/json"5 6 expect: “result & status when call the REST API”7 def result = rest.get(path: uri, query: [address:address])8 resultsIsEmpty == result.data.results.isEmpty()9 result.data.status == status10 11 where: “address takes different values with different results & status”12 address | resultsIsEmpty | status13 'Madrid'| false | 'OK'14 'abdkji'| true | 'ZERO_RESULTS'15 '186730'| false | 'ZERO_RESULTS' // This fails!16 17 }


Condition not satisfied:

result.data.status == status| | | | || | OK | ZERO_RESULTS| | false| | 11 differences (8% similarity)| | (---)O(K-------)| | (ZER)O(_RESULTS)| [results:[[address_components:[[long_name:186730, short_name:186730, types:[postal_code]], [long_name:Russia, short_name:RU, types:[country, political]]], formatted_address:Russia, 186730, geometry:[bounds:[northeast:[lat:61.84356, lng:30.2495827], southwest:[lat:61.4653021, lng:30.0576869]], location:[lat:61.67159349999999, lng:30.1745203], location_type:APPROXIMATE, viewport:[northeast:[lat:61.84356, lng:30.2495827], southwest:[lat:61.4653021, lng:30.0576869]]], place_id:ChIJt3ErZ3qEmUYRPW2d-LubWzA, types:[postal_code]]], status:OK]groovyx.net.http.HttpResponseDecorator@5f5f6fd6

Assertions


Reports


dependencies { testCompile("org.springframework.boot:spring-boot-starter-test") testCompile("org.springframework:spring-test") testRuntime("org.spockframework:spock-spring:0.7-groovy-2.0") { exclude group: 'org.spockframework', module: 'spock-core' } testCompile("org.spockframework:spock-core:0.7-groovy-2.0") { exclude group: 'org.codehaus.groovy', module: 'groovy-all' } … }

Dependencies


● Simple Spring Boot Application with Spock Test:● https://github.com/tomaslin/gs-spring-boot-spock

● Documentation: ● http://docs.spockframework.org

More information

https://github.com/tomaslin/gs-spring-boot-spock

http://docs.spockframework.org/


Executing...


Anywhere!!


Anywhere

Mix Java & Groovy easily

More expressive, simple & flexible than Java

Less code → less errors → more productivity

Extension of JDK -> GDK

@CompileStatic @TypeChecked

Domain classes, Controllers, Repositories,...


Groovy domain, repository and controller

DEMO...


Customer.groovy

1 import javax.persistence.*2 3 @Entity4 public class Customer {5 6 @Id7 @GeneratedValue(strategy= GenerationType.AUTO)8 long id;9 String firstName;10 String lastName;11 12 @Override13 String toString() {14 "Customer[id=$id, firstName=$firstName, lastName=$lastName"15 }

Domain class


Repository

CustomerRepository.groovy

1 import com.paradigma.springOne2gx.Customer2 import org.springframework.data.repository.CrudRepository3 import org.springframework.data.rest.core.annotation.RepositoryRestResource4 5 import java.util.List6 7 @RepositoryRestResource(collectionResourceRel = "customers", path = "customer")8 public interface CustomerRepository extends CrudRepository<Customer, Long> {9 10 List<Customer> findByLastName(@Param(value = "lastName") String lastName)11 12 }


Controllers

CustomerController.groovy

1 import org.springframework.beans.factory.annotation.Autowired2 import org.springframework.stereotype.Controller3 import org.springframework.web.bind.annotation.*4 5 @Controller6 public class CustomerController {7 8 @Autowired9 CustomerRepository customerRepository10 11 @RequestMapping("/customer/{id}")12 @ResponseBody13 public Customer findById(@PathVariable Long id) {14 return customerRepository.findOne(id)15 }


Adding customers in Application.groovy

1 @SpringBootApplication2 class Application {3 4 static void main(String[] args) {5 6 ConfigurableApplicationContext context = SpringApplication.run(Application.class)7 8 CustomerRepository repository = context.getBean(CustomerRepository.class)9 10 // save a couple of customers11 [[firstName:"Rachel Karen", lastName:"Green"],[firstName:"Monica E.", lastName:"Geller"],12 [firstName:"Phoebe", lastName:"Buffay"],[firstName:"Joey", lastName:"Tribbiani"],13 [firstName:"Ross", lastName:"Geller"],[firstName:"Chandler Muriel", lastName:"Bing"]].each {14 repository.save(new Customer(it)) 15 }16 17 // print all customers18 def customers = repository.findAll()19 println "Customers found with findAll():"20 customers.each { println it }21 22 // find a customer by ID23 Customer customer = repository.findOne(1L)24 println "Customer found with findOne(1L): $customer"25 26 // find customers by last name27 def lastName = "Bing"28 customers = repository.findByLastName(lastName)29 println "Customer found with findByLastName('$lastName'):"30 customers.each { println it }


dependencies { compile("org.springframework.boot:spring-boot-starter-data-rest")

compile("org.springframework.boot:spring-boot-starter-data-jpa")compile("com.h2database:h2")

… }

Dependencies

More information & exampleshttps://spring.io/guides/gs/accessing-data-jpa/

https://spring.io/guides/gs/accessing-data-rest/


Executing...


Groovy Templates


Groovy Template Framework

Based MarkupBuilder

Groovy DSL’s

Render readable views

Replace variables easily

Layouts

Groovy Templates


Groovy templates

DEMO...


list.tpl

1 layout 'layouts/main.tpl',2 pageTitle: 'List customers',3 mainBody: contents {4 ul {5 customers.each { customer ->6 li {7 p("$customer.firstName $customer.lastName ")8 }9 }10 }11 div{12 a(href:"/", "Go to home")13 }14 }


dependencies { compile("org.springframework.boot:spring-boot-starter-groovy-templates") … }

https://github.com/spring-projects/spring-boot/tree/master/spring-boot-samples/spring-boot-sample-web-groovy-templates

Spring Projects Example

Dependencies


Executing...


GORM


Automatic mapping for entities

Dynamic finders, criterias, persistence methods, validation, mappings,

constraints…

Expressive and simple code

implicit getters & setters

implicit constructors

implicit primary key

For Hibernate

For MongoDB

Grails Object Relational Mapping


GORM in Spring Boot

DEMO...


Customer.groovy

1 import grails.persistence.*2 3 @Entity4 public class Customer {5 6 @Id7 @GeneratedValue(strategy= GenerationType.AUTO)8 long id;9 String firstName;10 String lastName;11 12 @Override13 String toString() {14 "Customer[id=$id, firstName=$firstName, lastName=$lastName"15 }


1 // lines in application main class2 3 [[firstName:"Rachel Karen", lastName:"Green"],4 [firstName:"Monica E.", lastName:"Geller"],5 [firstName:"Chandler Muriel", lastName:"Bing"]].each {6 new Customer(it).save()7 }8 9 def customers = Customer.list() // implicit method list()10 customers.each {11 println it12 }13 14 Customer customer = Customer.get(1L) // implicit method get(...)15 println "Customer found with get(1L): $customer"16 17 def lastName = "Bing"18 customers = Customer.findAllByLastName(lastName)19 // implicit methods findAllBy... findBy...


dependencies { compile("org.grails:gorm-hibernate4-spring-boot:1.1.0.RELEASE") compile("com.h2database:h2") … }

Dependencies


Executing...


GSP's


Groovy Server Pages is used by Grails

Large list of useful Tag Libraries

Easy to define new Tags

Not only views

Layouts & Templates

Reuse Code

Groovy Server Pages


GSP's in Spring Boot

Some code...


<g:if test="${session.role == 'admin'}"> <%-- show administrative functions --%></g:if><g:else> <%-- show basic functions --%></g:else>

<g:each in="${[1,2,3]}" var="num"> <p>Number ${num}</p>

</g:each>

<g:findAll in="${books}" expr="it.author == 'Stephen King'"> <p>Title: ${it.title}</p>

</g:findAll>

<g:dateFormat format="dd-MM-yyyy" date="${new Date()}" />

<g:render template="bookTemplate" model="[book: myBook]" />


dependencies { compile("org.grails:grails-gsp-spring-boot:1.0.0") compile("org.grails:grails-web-gsp:2.5.0") compile("org.grails:grails-web-gsp-taglib:2.5.0") compile("org.grails:grails-web-jsp:2.5.0") … }

Dependencies


Conclusions


If you use Groovy…

Less code → Less errors → More productivity

GDK → More features → Cool utilities

Spock → Cool Tests

Super-vitaminized project!!

Why use Groovy?


That's all

THANKS!!

using groovy & grails in your spring boot project

Technology