Agile Web Development with Groovy & Grails Groovy & Grails

Groovy

Groovy

Why?

© 2008 BearingPoint, Inc.

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Groovy

Java Jobs © 2008 BearingPoint, Inc.

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Groovy

Java EE Jobs © 2008 BearingPoint, Inc.

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Groovy

Ruby On Rails Jobs © 2008 BearingPoint, Inc.

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Groovy

JSR 241

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Groovy

„Java-stylish with a Ruby-esque feeling“

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Groovy

 „Groovy is not a replacement for the Java programming language; it‘s a complement to that language“ Richard Monson-Haefel, award winning author & technical analyst

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Groovy

GroovyBeans class GroovyBean { String name }

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Groovy

Autoboxing def b = new GroovyBean() b.name = “groovy bean“

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Groovy

Duck Typing  „When I see a bird that walks like a duck and swims like a duck and quacks like a duck, I call that bird a duck.“ Poem by James Whitcomb Riley

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Groovy

Expressiveness

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Groovy

Java: java.net.URLEncoder.encode(“a b“);

Groovy: URLEncoder.encode ‘a b‘

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Groovy

GStrings

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Groovy

def name = “world“ def message = “Hello ${name}“

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Groovy

def text = “““ Ein längerer String mit Zeilenumbrüchen “““

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Groovy

Native Lists, Maps, Regex

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Groovy

Lists def aList

= []

def myList = [22,55,33]

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Groovy

Maps def emptyMap = [:] def myMap

= [“name“: “Max“, “age“ : “33“ ]

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Groovy

Maps myMap.name == “Max“ myMap[“age“] == “33“

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Groovy

Regular Expressions “cheesecheese“ =~ “cheese“ “cheesecheese“ =~ /cheese/ “potatoe“ ==~ /potatoe?/ “potato“ ==~ /potatoe?/ © 2008 BearingPoint, Inc.

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Groovy

Loops for (int i=0;i<6;i++) {} def list = [1, 2, 3] for (i in list) {} for (i in 0..9) {} 10.times {} © 2008 BearingPoint, Inc.

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Groovy

Closures def myClosure = { /* do something */ }

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Groovy

[3,1,2].each { print “value:“+it }

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Groovy

Builders def xml = new groovy.xml.MarkupBuilder() xml.authors { author(name:‘Stephen King‘) { book(title:‘The Shining‘) book(title:‘The Stand‘) } author(name:‘James Patterson‘) { book(title:‘Along Came a Spider‘) } } © 2008 BearingPoint, Inc.

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Groovy

Builders

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Groovy

The Groovy Truth if (myString != null && myString.length() > 0) { myMethod(myString); }

if (myString) myMethod(myString) © 2008 BearingPoint, Inc.

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Groovy

Save Dereferencing Long id=null; if (session.getAttribute(“user“) != null) { id = ((User) session.getAttribute(“user“)).getId(); }

def id = session.user?.id © 2008 BearingPoint, Inc.

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Groovy

Meta Class Concept

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Groovy

IDE Integration

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Groovy

Domain Specific Language (DSL)

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Groovy

Java: public class RecursiveFileReading { public static void main(String[] args) { printAllFiles(new File(".")); } public static final void printAllFiles(File root) { File[] allChildren = root.listFiles(); for (File child : allChildren) { if (child.isDirectory()) { RecursiveFileReading.printAllFiles(child); } else { System.out.println(child.toString()); } } } }

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Groovy

Groovy: groovy -e “new File(‘.‘).eachFileRecurse { println

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it }“

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Groovy

 „There is a value for learning Groovy for its own sake. It will open your mind...“

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Grails

Grails

Rapid Application Develoment (RAD)

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Grails

Full Stack Framework

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Grails

Convention Over Configuration (CoC)

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Grails

RESTfull Representational State Transfer

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Grails

GET © 2008 BearingPoint, Inc.

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Grails

POST © 2008 BearingPoint, Inc.

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Grails

PUT © 2008 BearingPoint, Inc.

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Grails

DELETE © 2008 BearingPoint, Inc.

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Grails

HEAD © 2008 BearingPoint, Inc.

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Grails

OPTIONS © 2008 BearingPoint, Inc.

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Grails

RESTfull http://localhost:8080/application/user/profile/123 Controller Action ID

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Grails

DRY Paradigm (Don‘t Repeat Yourself)

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Grails

 Leverages existing hardware  Leverages existing Java/Framework knowledge

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Grails

Components Grails Java EE Java Language

JDK Java Virtual Machine

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Grails

UI, AJAX & RIA Frameworks

YUI

GWT © 2008 BearingPoint, Inc.

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Grails

Plugin API  JSF  Struts  JMS  ACEGI/Spring Security, JSecurity  OpenID  Functional Testing (Canoo WebTest)  Apache Axis 2, XFire © 2008 BearingPoint, Inc.

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Grails

GORM Groovy Object-Relational Mapping

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Grails

GORM class Book { String title } © 2008 BearingPoint, Inc.

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Grails

GORM class Book {String author String title Date releaseDate static constraints = { author(blank:false, size:2..30) releaseDate(nullable: true) } } } } © 2008 BearingPoint, Inc.

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Grails

GORM def book = new Book() book.author = “author A“ book.title = “title 1“ book.save()

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Grails

GORM def book = new Book() book.author = “author A“ book.title = “title 1“ if (book.save()) { /* successfull flow */ } else { /* error flow */ } © 2008 BearingPoint, Inc.

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Grails

(Dynamic) Finders def macBook = Book.get(1) def macBook = Book.findByTitle(“MacBook“) def macBook = Book.findByTitleAndAuthor(“MacBook“, “Apple“)

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Grails

Groovy Server Pages (GSP)

Book list

Title	Author
${it.title}	${it.author}

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Grails

Groovy Server Pages (GSP) Hello Fred! Hello ${name}! Do I know you?

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Grails

Groovy Server Pages (GSP)

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Grails

Scaffolding  Dynamic Scaffolding  Static Scaffolding

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Grails

How does it look like?

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Grails

Success Stories?

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Grails

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Grails

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Grails

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Grails

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Grails

http://groovy.codehaus.org/ http://www.grails.org

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Grails

Dirk König - Groovy In Action Manning, 2007

Graeme Keith Rocher - The Definitive Guide To Grails Apress, 2006

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