1. G*
JJUG CCC 2011 Spring
@kiy0taka

2. ※ kiy0taka 0

3. G*

4. Groovy?

5. HelloWorld.java
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}

6. HelloWorld.groovy
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!");
}
}
Java

7. HelloWorld.groovy
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World!")
}
}

8. HelloWorld.groovy
public class HelloWorld {
public static void main(String[] args) {
System.out.println "Hello, World!"
}
}

9. HelloWorld.groovy
public static void main(String[] args) {
System.out.println "Hello, World!"
}

10. HelloWorld.groovy
System.out.println "Hello, World!"
main

11. HelloWorld.groovy
println "Hello, World!"
System.out.println → println

12. One-Liner
groovy -e "println 'Hello, World!'"

14. Java
def file = new File("./hoge.txt")

15. def text = new File("./hoge.txt").text

16. Web
new URL('http://www.java-users.jp/contents/').getText('UTF-8')

17. String
println 'ls -la /opt/local'.execute().text
total 8
drwxr-xr-x 12 root admin 408 11 23 19:32 .
drwxr-xr-x 3 root admin 102 11 7 14:34 ..
drwxr-xr-x 5 root wheel 170 11 24 13:02 Library
drwxr-xr-x 686 root admin 23324 11 27 18:06 bin
drwxr-xr-x 25 root admin 850 11 24 17:01 etc
drwxr-xr-x 177 root admin 6018 11 24 17:01 include
drwxr-xr-x 988 root admin 33592 11 24 17:01 lib
drwxr-xr-x 22 root admin 748 11 24 16:17 libexec
lrwxr-xr-x 1 65534 wheel 9 11 23 18:42 man -> share/man
drwxr-xr-x 5 root admin 170 11 24 13:37 sbin
drwxr-xr-x 76 root admin 2584 11 27 18:06 share
drwxr-xr-x 8 root admin 272 11 24 13:02 var

18. import
import java.lang
import java.math
import java.io
import java.net
import java.util
import groovy.lang
import groovy.util

19. Java
import org.apache.poi.hssf.usermodel.*
def workBook = new HSSFWorkbook(new File('./foo.xls')
workBook.newInputStream()).sheets.each { sheet ->
sheet.firstRowNum.upto(sheet.lastRowNum) {
sheet.getRow(it).with { row ->
row.firstCellNum.upto(row.lastCellNum - 1) {
println row.getCell(it).stringCellValue
}
}
}
}

20. jar
@Grab('org.apache.poi:poi:3.2-FINAL')
import org.apache.poi.hssf.usermodel.*
def workBook = new HSSFWorkbook(new File('./foo.xls')
workBook.newInputStream()).sheets.each { sheet ->
sheet.firstRowNum.upto(sheet.lastRowNum) {
sheet.getRow(it).with { row ->
row.firstCellNum.upto(row.lastCellNum - 1) {
println row.getCell(it).stringCellValue
}
}
}
}

21. Ant
def ant = new AntBuilder()
ant.unzip(src: 'xxx.zip', dest:'dest')
ant.mail(mailhost:'hostname', subject:'hello',
charset:'utf-8',
user:user,
password:password) {
from address:'xxx@example.com'
to address:'kiy0taka333@gmail.com'
message 'Hello World!'
}

24. // Groovy
$ time groovy -e "println 'Hello'"
Hello
real!0m1.292s
user!0m1.283s
sys! 0m0.192s
// GroovyServ
$ time groovyclient -e "println 'Hello'"
Hello
real!0m0.036s
user!0m0.001s
sys! 0m0.003s

26. Swing(Java)
contentPane.add(button);
package sample;
setDefaultCloseOperation(EXIT_ON_CLOSE);
import java.awt.Container; pack();
import java.awt.GridLayout; setVisible(true);
import java.awt.event.ActionEvent; }
import java.awt.event.ActionListener;
public static void main(String[] args) {
import javax.swing.JButton; SwingUtilities.invokeLater(new Runnable() {
import javax.swing.JFrame; public void run() {
import javax.swing.JLabel; new Hello();
import javax.swing.JTextArea; }
import javax.swing.SwingUtilities; });
}
public class Hello extends JFrame { }
public Hello() {
super("Hello");
Container contentPane = getContentPane();
contentPane.setLayout(new GridLayout(3, 1));
JLabel label = new JLabel("Label");
contentPane.add(label);
JTextArea textArea = new JTextArea("Text Area");
textArea.setColumns(20);
textArea.setRows(2);
contentPane.add(textArea);
JButton button = new JButton("Button");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
...
}
});

27. Groovy
import groovy.swing.SwingBuilder
new SwingBuilder().edt {
frame(title:'Hello', show:true, pack:true) {
gridLayout(cols:1, rows:3)
label 'Label'
textArea('Text Area', rows:2, columns:20)
button('Button', actionPerformed:{ evt ->
...
})
}
}

28. SwingBuilder
import groovy.swing.SwingBuilder
new SwingBuilder().edt {
frame(show:true, pack:true) {
tableLayout {
tr {
td { label 'UserName: ' }
td { textField columns:20 }
}
tr {
td { label 'Password: ' }
td { passwordField columns:20 }
}
tr {
td(colspan:2) { button 'Login' }
}
}
}
}

29. https://gist.github.com/913279

31. h2console.groovy
@Grab('org.mortbay.jetty:jetty-embedded:6.1.25')
@Grab('com.h2database:h2:1.2.144')
@Grab('mysql:mysql-connector-java:5.1.13')
import org.mortbay.jetty.Server
import org.mortbay.jetty.servlet.Context
import org.h2.server.web.WebServlet
def server = new Server(8080)
new Context(server, "/", Context.SESSIONS)
.addServlet(WebServlet, "/*")
server.start()
https://gist.github.com/717932

33. please show the
square_root of 100

34. show = { println it }
square_root = { Math.sqrt(it) }
def please(action) {
[the: { what ->
[of: { n -> action(what(n)) }]
}]
}
please(show).the(square_root).of(100)

35. show = { println it }
square_root = { Math.sqrt(it) }
def please(action) {
[the: { what ->
[of: { n -> action(what(n)) }]
}]
}
please show the square_root of 100

36. Object.metaClass. =
Object.metaClass. =
{ clos -> clos(delegate) }
= { it }
= { println it }
= { Math.sqrt(it) }
100

39. import static groovyx.gpars.GParsPool.withPool
def list = [1, 2, 3, 4, 5]
withPool {
def result = list.collectParallel { it * 2 }
assert result == [2, 4, 6, 8, 10]
}

41. import groovy.json.* def slurper = new JsonSlurper()
def json = slurper.parseText(text)
def text = '''[ assert json == [
["aaa", "bbb", "ccc"], ["aaa", "bbb", "ccc"],
{ [
"key1" : "value1", "key1" : "value1",
"key2" : "value2", "key2" : "value2",
"key3" : "value3", "key3" : "value3",
"key4" : "" "key4" : ""
}, ],
["ddd", "eee", "fff"] ["ddd", "eee", "fff"]
] ]
'''

42. import groovy.json.*
def json = new JsonBuilder()
json (
["aaa", "bbb", "ccc"],
[
"key1" : "value1",
"key2" : "value2",
"key3" : "value3",
"key4" : ""
],
["ddd", "eee", "fff"]
)
println json

44. import org.gcontracts.annotations.*
@Invariant({ speed() >= 0 })
class Rocket {
@Requires({ isStarted() })
@Ensures({ old.speed < speed })
def accelerate() { ... }
boolean isStarted() { ... }
def speed() { ... }
}

45. def plus2 = { it + 2 }
def times3 = { it * 3 }
def times3plus2 = plus2 << times3
assert times3plus2(3) == 11
assert times3plus2(4) == plus2(times3(4))
def plus2times3 = times3 << plus2
assert plus2times3(3) == 15
assert plus2times3(5) == times3(plus2(5))
assert times3plus2(3) == (times3 >> plus2)(3)

48. @Log
import groovy.util.logging.*
@Log
class Car {
Car() {
log.info 'Car constructed'
}
}
def c = new Car()
@Commons @Log4j @Slf4j

49. @Log @Commons @Log4j @Slf4j
@Field @PackageScope
@AutoClone @AutoExternalizable
@ThreadInterrupt @TimedInterrupt
@ConditionalInterrupt @ToString
@EqualsAndHashCode @TupleConstructor
@Canonical @InheritConstructors
@WithReadLock @WithWriteLock
@ListenerList

51. Grails

52. create-app generate-all
create-controller generate-controller
create-domain-class generate-views
create-script package
create-service run-app
create-tag-lib run-war
create-unit-test test-app

54. package myapp
class Message {
String text
static constraints = {
text blank:false, maxSize:500
}
}

55. package myapp
class MessageController {
static scaffold = true
}

63. Gaelyk:Controller
log.info "Setting attribute datetime"
request.datetime = new Date().toString()
log.info "Forwarding to the template"
forward '/datetime.gtpl'

64. Gaelyk:View
<% include '/WEB-INF/includes/header.gtpl' %>
<h1>Date / time</h1>
<p>
<% log.info "outputing the datetime attribute" %>
The current date and time:
${request.datetime}
</p>
<% include '/WEB-INF/includes/footer.gtpl' %>

65. Gaelyk:Datastore
import com.google.appengine.api.datastore.Entity
def entity = new Entity("person")
entity.name = "Kiyotaka Oku"
entity.age = 31
entity.save()

66. datastore blobstore
memcache oauth
urlFetch namespace
mail capabilities
images channel
users files
user backends
defaultQueue lifecycle
queues localMode
xmpp app

67. Gaelyk:Datastore
import com.google.appengine.api.datastore.*
import static com.google.appengine.api.datastore.FetchOptions.Builder.*
import static com.google.appengine.api.datastore.Query.FilterOperator.*
import static com.google.appengine.api.datastore.Query.SortDirection.*
def query = new Query('person').with {
addFilter 'age', GREATER_THAN_OR_EQUAL, 30
addSort 'name', ASCENDING
}
def persons = datastore.prepare(query).asList(withLimit(21))

68. Gaelyk:Mail
mail.send sender: "kiy0taka333@gmail.com",
to: "xxx@example.com",
subject: "Hello",
textBody: "Hello, how are you doing?"

69. Gaelyk:TaskQueue
defaultQueue << [
countdownMillis: 1000, url: "/task/dailyEmail",
taskName: "Send daily email newsletter",
method: 'PUT', params: [date: '20090914'],
payload: content
]

71. Griffon

72. Getting Started
$ griffon create-app myapp
$ cd myapp
$ griffon run-app

73. Griffon MVC
MVC

77. Gradle

78. apply plugin: 'groovy'
repositories {
mavenCentral()
}
dependencies {
groovy 'org.codehaus.groovy:groovy:1.8.0'
compile 'junit:junit:4.8.2'
}

79. $ gradle clean build
:clean
:compileJava
:compileGroovy
:processResources
:classes
:jar
:assemble
:compileTestJava
:compileTestGroovy
:processTestResources
:testClasses
:test
:check
:build
BUILD SUCCESSFUL
Total time: 13.766 secs

80. task checksum << {
fileList('../antLoadfileResources').each {File file ->
ant.checksum(file: file, property: "cs_$file.name")
println "$file.name Checksum: ${ant.properties["cs_$file.name"]}"
}
}
task loadfile << {
fileList('../antLoadfileResources').each {File file ->
ant.loadfile(srcFile: file, property: file.name)
println "I'm fond of $file.name"
}
}
File[] fileList(String dir) {
file(dir).listFiles({file -> file.isFile() } as FileFilter).sort()
}

83. G*Magazine

84. G*