use groovy&grails in your spring boot projects

La importancia de un buen título en presentaciones

Use Groovy & Grails in your Spring Boot projects, don't be afraid!

@fatimacasau


Fátima Casaú Pérez

Software Engineer for over 7 years ago

Java Architect & Scrum Master in Paradigma Tecnológico

Specialized in Groovy & Grails environments

Recently, Spring Boot world

@fatimacasau

Use Groovy & Grails in your Spring Boot projects, don't be afraid!@fatimacasau


What is Spring Boot?

What is Groovy?

Where could you use Groovy in your Spring Boot Projects?● Gradle● Tests● Groovy Templates● Anywhere?● GORM● GSP’s

Overview

@fatimacasauUse Groovy & Grails in your Spring Boot projects, don't be afraid!


Spring Boot



Standalone

Auto-configuration - CoC

No XML

Embedded Container and Database

Bootstrapping

Groovy!!

Run quickly - Spring Boot CLI

projects.spring.io/spring-boot

Spring Boot


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


Spring Boot application in a single tweet

DEMO...


GVM

gvmtool.net

> gvm install springboot


http://gvmtool.net/



HelloWorld.groovy

1 @Controller2 class ThisWillActuallyRun {3 @RequestMapping("/")4 @ResponseBody5 String home() {6 "Hello World!"7 }8 }


Groovy



Dynamic language

Optionally typed

@TypeChecked & @CompileStatic

Java Platform

Easy & expressive syntax

Powerful featuresclosures, DSL, meta-programming, functional programming, scripting, ...

Groovy



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 application with Gradle

DEMO...



GVM

> gvm install gradle> gradle build> gradle tasks



build.gradle

1 buildscript {2 repositories {3 mavenCentral()4 }5 dependencies {6 classpath("org.springframework.boot:springbootgradleplugin:1.2.2.RELEASE")7 }8 }9 10 apply plugin: 'groovy'11 apply plugin: 'idea'12 apply plugin: 'springboot'13 14 jar {15 baseName = 'helloworld'16 version = '0.1.0'17 }18 19 repositories {20 mavenCentral()21 }22 23 dependencies {24 compile("org.springframework.boot:springbootstarterweb")25 }


Testing with Spock



Spock framework & specification

Expressive

Groovy DSL’s

Easy to read tests

Well documented

Powerful assertions

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.toString().contains('Madrid') 13 }



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 expect: “result & status when call the REST API”6 def result = rest.get(path: uri, query: [address:address])7 resultsIsEmpty == result.data.results.isEmpty()8 result.data.status == status9 where: “address takes different values with different results & status”10 address | resultsIsEmpty | status11 'Madrid'| false | 'OK'12 'abdkji'| true | 'ZERO_RESULTS'13 '186730'| false | 'ZERO_RESULTS' // This fails!14 15 }


Groovy templates



Groovy Template Framework

Based MarkupBuilder

Groovy DSL’s

Render readable views

Replace variables easily

Groovy templates



Groovy Templates

DEMO...



1 ul {2 people.each { p >3 li(p.name)4 }5 }

With the following model

6 def model = [people: [7 new Person(name:'Bob'), 8 new Person(name:'Alice')9 ]]

Renders the following

10 <ul><li>Bob</li><li>Alice</li></ul>


Anywhere!



Anywhere

Mix Java & Groovy easily

More expressive, simple & flexible than Java

Extension of JDK -> GDK

@CompileStatic @TypeChecked

Controllers, Services, Model,...



Groovy Controller

DEMO...



HelloWorld.groovy

1 2 @Controller 3 class ThisWillActuallyRun { 4 @RequestMapping("/") 5 @ResponseBody 6 String home() { 7 "Hello World!" 8 } 9 }

@groovy.transform.CompileStatic


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

GORM: Grails Object Relational Mapping



GORM for Hibernate

DEMO...



Customer.groovy

1 @Entity2 public class Customer {34 String firstName;5 String lastName;67 static constraints = {8 firstName blank:false9 lastName blank:false10 }11 static mapping = {12 firstName column: 'first_name'13 lastName column: 'last_name'14 }15 }



1 [[firstName:"Jack", lastName:"Bauer"],2 [firstName:"Michelle", lastName:"Dessler"]].each {3 new Customer(it).save()4 }5 6 def customers = Customer.findAll()7 8 customers.each {9 println it10 }11 12 def customer = Customer.get(1L)13 14 customers = Customer.findByLastName("Bauer")15 customers.each {println it}


GSP's



Groovy Server Pages is used by Grails

Large list of useful Tag Libraries

Easy to define new Tags

Not only viewsLayouts & Templates

Reuse Code

GSP's: Groovy Server Pages



GSP's in Spring Boot

DEMO...



1 <g:if test="${session.role == 'admin'}">2 <% show administrative functions %>3 </g:if>4 <g:else>5 <% show basic functions %>6 </g:else>

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

___________________________________________________________________1 <g:findAll in="${books}" expr="it.author == 'Stephen King'">2 <p>Title: ${it.title}</p>3 </g:findAll>

___________________________________________________________________1 <g:dateFormat format="ddMMyyyy" date="${new Date()}" />

___________________________________________________________________1 <g:render template="bookTemplate" model="[book: myBook]" />


Conclusions



If you use Groovy…

Less code

More features

Cool Tests

Cool utilities

Why not? Please try to use Groovy!



One moment...


MVC Spring based Apps

Convention Over Configuration

Bootstrapping

Groovy

GORM

GSP’s ...

It's sounds like Grails!



Why do you not use Grails?



Thanks!!@fatimacasau


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