Gradle: Build tool that rocks with DSL

Rajmahendra HegdeJUGChennai Founder & Leadrajmahendra@gmail.com

tweet: @rajonjava

aboutMe {

name: 'Rajmahendra Hegde'

community: name: 'Java User Group – Chennai', role: 'Founder and Lead', url: 'http://jugchennai.in'

profession: company: 'Logica', designation: 'Project Lead'

javaDeveloperSince: 1999

contributions {

jcp: [jsrID: 354, name: 'Money and Currency API'],[jsrID: 357, 'Social Media']

communityProject: 'Agorava', 'VisageFX', 'Scalaxia.com', 'gradle-weaverfx-plugin'

}

interests: 'JUG Activities','JEE', 'Groovy', 'Scala', 'JavaFX', 'VisageFX', 'NetBeans', 'Gradle'

twitter: '@rajonjava'

email: 'rajmahendra@gmail.com'}

Agenda

• Build tools• Build tool basics• Gradle• Getting Started• Gradle Tasks• Gradle with Ant• Gradle with Maven• Plugins• Multi Project Support• Project Templates• IDEs Support

Automated Build Tool

Source Files,Resource Filesetc.

Jar

War

jpi

XYZ...

Build Tool

Build Tool

• Initialize• checkout• Compile• Check-style• Test• Code coverage • Jar• War• Ear• Deploy• etc...

• Generic build process• Dev, Test, Integ,

environment• Continuous Integration

Evolution of build tools

• Javac, Jar.. - Command based• IDEs – Application based

(a need for building application outside the IDEs!) (this is the age of onsite deployment and Continuous Integration)

• Ant – Task based - (XML)• Maven – Goal based (XML)• …• Gradle – A mix of good practices/tools(ant, maven,ivy etc.) with a flavor of

DSL

Build Tools

Gradle is

• A general purpose Java build system• Platform independent• DSL based • Built for java based projects • Full support of Grooy, Ant and Maven• Task based system• Convention over configuration• Flexible, scalable, extensible• Plugins • Flexible multi-project support• Free and open source

Why

Core JavaNo

<XML>Use

@annotation

JVM LanguageNo

<XML>Use

DSL{}

A domain-specific language (DSL) is a programming language or specification language dedicated to a particular problem domain, a particular problem representation technique, and/or a particular solution technique. - Wikipedia

Examples

Chess Notation 1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 1. P-K4 P-K4 2. N-KB3 N-QB3 3. B-B4 B-B4

Music Western Musical Notation – C, D, E, F, G, A, B, C Solfège syllables – Do, Re, Mi, Fa, Sol, La, Ti, Do. Carnatic Music Notation – Sa Re Ga Ma Pa Da Ne Sa Guitar Tab - 0 1 2 3 4 Harmonica Tab – 1b 1b 2d 2d

Rubik's Cube Notation - d', d2. f, f', f2, b, b', b2

Very popular in our own field SQL! SELECT * FROM MYTABLE WHERE MYFIELD = 4

And many...

DSL? Domain Specific Language

DSLs in Action

By - Debasish GhoshForewords by: Jonas Bonér

December, 2010 | 376 pages ISBN: 9781935182450

DSLs in Action introduces the concepts you'll need to build high-quality domain-specific languages. It explores DSL implementation based on JVM languages like Java, Scala, Clojure, Ruby, and Groovy and contains fully explained code snippets that implement real-world DSL designs. For experienced developers, the book addresses the intricacies of DSL design without the pain of writing parsers by hand.

http://www.manning.com/ghosh/

Read about DSL

• Download binary zip from gradle.org• Unzip in your favorite folder

• Set GRADLE_HOME Env. Variable • Add GRADLE_HOME[/ or \ ]bin to PATH

• To test $ gradle -v

• Build File name: – build.gradle– gradle.properties– settings.gradle

Getting Started$ gradle -v

--------------------------------------Gradle 1.0-rc-2--------------------------------------

Gradle build time: Tuesday, April 24, 2012 11:52:37 PM UTCGroovy: 1.8.6Ant: Apache Ant(TM) version 1.8.2 compiled on December 20 2010Ivy: 2.2.0JVM: 1.6.0_31 (Apple Inc. 20.6-b01-415)OS: Mac OS X 10.7.3 x86_64

• Initializationl Initializes the scope of the buildl Identifies projects [multi-project env.] involvedl Creates Project instance

• Configurationl Executes buildscript{} for all its scopel Configures the project objects

• Executionl Determines the subset of the tasksl Runs the build

Build Lifecycle

task mytask << { println 'Hello World'}

mytask.doFirst { println 'The First'}

mytask.doLast { println 'The Last' }

mytask << {println 'Add more'

}

Gradle Tasks$ gradle mytask:mytaskThe FirstHello WorldThe LastAdd moreBUILD SUCCESSFUL

task mytask << {

String myString = 'Hello World'

def myMap = ['map1': '1', 'map2':'2']

println myString println myString.toUpperCase() println 'Map2: ' + myMap['map2']

5.times { if (it % 2 == 0) println (“Count $it”) } }

Gradle is Groovy$ gradle mytask:mytaskHello WorldHELLO WORLDMap2: 2Count 0Count 2Count 4

BUILD SUCCESSFUL

task task1(dependsOn: 'task2') << { println 'Task 1'}

task task2 (dependsOn: 'task3') << { println 'Task 2'}

task task4 << { println 'Task 4'}task task3 (dependsOn: task4) << { println 'Task 3'}

Gradle Task Dependencies $ gradle task1:task4Task 4:task3Task 3:task2Task 2:task1Task 1BUILD SUCCESSFUL

defaultTasks 'task3', 'task1'

task task1 << { println 'Task 1'}

task task2 << { println 'Task 2'}

task task4 << { println 'Task 4'}

task task3 << { println 'Task 3'}

Gradle defaultTasks $ gradle:task3Task 3:task1Task 1BUILD SUCCESSFUL

task distribution << { println "We build the zip with version=$version"}

task release(dependsOn: 'distribution') << { println 'We release now'}

gradle.taskGraph.whenReady {taskGraph → if (taskGraph.hasTask(release)) {version = '1.0' } else { version = '1.0-SNAPSHOT' }}

Gradle DAG $ gradle distribution:distributionWe build the zip with version=1.0-SNAPSHOTBUILD SUCCESSFUL

$ gradle release:distributionWe build the zip with version=1.0:releaseWe release nowBUILD SUCCESSFUL

From Gradle Userguide

task copy(type: Zip) { from 'resources' into 'target' include('**/*.properties')}

// OR

task myCopy(type: Zip)myCopy.configure { from('source') into('target') include('**/*.properties')}

Configuring Tasks // ORtask myCopy(type: Zip)myCopy { from 'resources' into 'target' include( '**/*.properties')}

// OR

task(myCopy, type: Zip) .from('resources') .into('target') .include( '**/*.properties')

Gradle with Ant

• Ant is first-class-citizen for Gradle• ant Builder • Available in all .gradle file

• Ant .xml• Directly import existing ant into Gradle build!• Ant targets can be called directly

task callAnt << { ant.echo (message: 'Hello Ant 1') ant.echo ('Hello Ant 2') ant.echo message: 'Hello Ant 3' ant.echo 'Hello Ant 4'}

task myCompile << {

ant.java(classname: 'com.my.classname',classpath: ${sourceSets.main.runtimeClasspath.asPath}")

}

Gradle with Ant...$ gradle callAnt:callAnt[ant:echo] Hello Ant 1[ant:echo] Hello Ant 2[ant:echo] Hello Ant 3[ant:echo] Hello Ant 4

BUILD SUCCESSFUL

task runPMD << {

ant.taskdef(name: 'pmd', classname: 'net.sourceforge.pmd.ant.PMDTask',classpath: configurations.pmd.asPath) ant.pmd(shortFilenames: 'true', failonruleviolation: 'true', rulesetfiles: file('pmd-rules.xml').toURI().toString()) { formatter(type: 'text', toConsole: 'true') fileset(dir: 'src') }}

Gradle with Ant...

<!-- build.xml --><project> <target name="antHello"> <echo>Hello, from Ant.</echo> </target></project>

// build.gradleant.importBuild 'build.xml'

Gradle calls Ant$ gradle antHello:antHello[ant:echo] Hello, from Ant.

BUILD SUCCESSFUL

<!-- build.xml --><project> <target name="callAnt">

<echo>Hello, from Ant.</echo> </target></project>

// build.gradleant.importBuild 'build.xml'

callAnt << {println 'Gradle adds behaviour

to Ant task.'}

Gradle adds behaviour to Ant task$ gradle callAnt:callAnt[ant:echo] Hello, from Ant.Gradle adds behaviour to Ant task

BUILD SUCCESSFUL

Gradle with Maven

• Ant Ivy• Gradle build on Ivy for dependency management

• Maven Repository• Gradle works with any Maven repository

• Maven Project Structure• By default Gradle uses Maven project structure

Maven Project Structure

Images: http://educloudsims.wordpress.com/

repository {

mavenCentral() mavenLocal()

maven { url: “http://repo.myserver.come/m2”, “http://myserver.com/m2” }

ivy { url: “http://repo.myserver.come/m2”, “http://myserver.com/m2” url: “../repo” } mavenRepo url: "http://twitter4j.org/maven2", artifactUrls: ["http://oss.sonatype.org/content/repositories/snapshots/", "http://siasia.github.com/maven2", "http://typesafe.artifactoryonline.com/typesafe/ivy-releases", "http://twitter4j.org/maven2"]

}

Gradle repository

dependencies {

compile group: 'org.springframework', name: 'spring-core', version: '2.0'

runtime 'org.springframework:spring-core:2.5'

runtime('org.hibernate:hibernate:3.0.5')

runtime "org.groovy:groovy:1.5.6"

compile project(':shared')

compile files('libs/a.jar', 'libs/b.jar')

runtime fileTree(dir: 'libs', include: '**/*.jar')

testCompile “junit:junit:4.5”

}

Gradle dependency

repositories { flatDir { name "localrepo" dirs "../repo" }}

uploadArchives { repositories { add project.repositories.fileRepo ivy { credentials { username "username" password "password" } url "http://ivyrepo.mycompany.com/m2" } }}

Gradle Publish

Plugin Support

Gradle Plugins

apply from: 'mybuild.gradle'

apply from: 'http://www.mycustomer.come/folders/mybuild.gradle'

apply plugin: 'java' apply plugin: 'war' apply plugin: 'jetty'

//Minimum gradle code to work with Java or War project:apply plugin: 'java' // ORapply plugin: 'war'apply plugin: 'jetty'

dependencies { testCompile “junit:junit:4.5”}

Java Pluginsapply plugin: 'java'

sourceCompatability = 1.7targetCompatability = 1.7

dependencies{ testCompile “junit:junit:4.5” }task "create-dirs" << { sourceSets*.java.srcDirs*.each { it.mkdirs() } sourceSets*.resources.srcDirs*.each { it.mkdirs() }}

src/main/java

src/main/resource

src/main/test

src/main/resource

War Pluginsapply plugin: 'war'

src/main/webapp

Jetty Pluginsapply plugin: 'jetty'

Property Default Value

httpPort 8080

• Android• AspectJ• CloudFactory• Cobertura• Ubuntu Packager• Emma• Exec• FindBug• Flex• Git• Eclipse• GWT• JAXB• ...

For more plugins : http://wiki.gradle.org/display/GRADLE/Plugins

Community Plugins

apply plugin: SayHelloPlugin

sayhello.name = 'Raj'

class SayHelloPlugin implements Plugin<Project> {

void apply(Project project) {

project.extensions.create("sayhello", SayHelloPluginExtension)

project.task('sayHello') << {

println "Hello " + project.sayhello.name }

}}

class SayHelloPluginExtension { def String name = 'Default'

}

Writing Custom Plugin$ gradle sayHello:sayHelloHello Raj

BUILD SUCCESSFUL

//If we remove//sayhello.name = 'Raj'$ gradle sayHello:sayHelloHello Default

BUILD SUCCESSFUL

Multi Project Support

Multi Project Support//settings.gradle - defines the project participates in the buildinclude 'api', 'services', 'web'

allprojects {apply plugin: 'java'group = 'org.gradle.sample'version = '1.0 task omnipotenceTask { println 'You find me in all the project' }

}

subprojects { repositories {mavenCentral()} dependencies { compile "javax.servlet:servlet-api:2.5" }task callHoldMyBro (dependsOn: ':elderBro:compileJava') {}}

project(':war') {

apply plugin: 'java'

dependencies {compile "javax.servlet:servlet-api:2.5", project(':api') }}

Gradle Project TemplatesA Gradle plugin which provides templates, and template methods like 'initGroovyProject' to users. This makes it easier to get up and running using Gradle as a build tool.

apply from: 'http://launchpad.net/gradle-templates/trunk/latest/+download/apply.groovy'

$ gradle createJavaProject

More Info: https://launchpad.net/gradle-templates

Gradle Project Templates// Inside apply.gradlebuildscript {

repositories {ivy {

name = 'gradle_templates'artifactPattern "http://launchpad.net/[organization]/trunk/

[revision]/+download/[artifact]-[revision].jar"}

}dependencies {

classpath 'gradle-templates:templates:1.2'}

}// Check to make sure templates.TemplatesPlugin isn't already added.if (!project.plugins.findPlugin(templates.TemplatesPlugin)) {

project.apply(plugin: templates.TemplatesPlugin)}

Gradle Wrapper// Write this code in your main Graldy build file.task wrapper(type: Wrapper) { gradleVersion = '1.0-rc-3'}

$ gradle wrapper

//Created files.myProject/ gradlew gradlew.bat gradle/wrapper/ gradle-wrapper.jar gradle-wrapper.properties

Gradle IDE Support

Reference • http://gradle.orga• http://gradle.org/overview• http://gradle.org/documentation• http://gradle.org/roadmap• http://docs.codehaus.org/display/GRADLE/Cookbook

http://www.gradle.org/toolinghttp://gradle.org/contribute

Q & A

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Find your nearest JUG at

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discussion@jug-india.java.net

May 5th JUGChennai - Chennai - Stephen Chin – http://jugchennai.in/javafxBOJUG – Bangalore - Simon Ritter, Chuk Munn Lee,Roger Brinkley and Terrence Barr PuneJUG – Pune - Arun Gupta

November 2nd & 3rd AIOUG Sangam '12 [Java Track] (Main Speaker as of now Arun Gupta)Call for Paper is open - http://www.aioug.org/sangamspeakers.php

JUGChennai

Java User Groups - Chennai

Main Website

http://jugchennai.inTweets: @jug_cG Group: jug-c

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Rajmahendra Hegderajmahendra@gmail.comtweet: @rajonjava