Groovy is a dynamic language that runs on the JVM and provides features like closures, builders, and domain specific languages that make developing Atlassian plugins more productive compared to Java. Groovy code is more concise and readable than equivalent Java code for many tasks like iterating over lists and parsing XML. Dynamic typing in Groovy does not preclude robust IDE support and tooling. Groovy can leverage Java libraries and is a fully-featured language suitable for professional development.

1. 1
1

2. Groovy Plugins
Why you should be developing
Atlassian plugins using Groovy
Dr Paul King, Director, ASERT
2
2

3. What is Groovy?
“Groovy is like a super version of Java. It
can leverage Java's enterprise capabilities
but also has cool productivity features like
closures, DSL support, builders and dynamic typing.”
Groovy
=
Java
–
boiler
plate
code
+
optional
dynamic
typing
+
closures
+
domain
specific
languages
+
builders
+
meta-­‐programming
3
3

4. What is Groovy?
Now free
4
4

5. What is Groovy?
What alternative JVM language are you using or intending to use
http://www.jroller.com/scolebourne/entry/devoxx_2008_whiteboard_votes
http://www.leonardoborges.com/writings
http://it-republik.de/jaxenter/quickvote/results/1/poll/44
(translated using http://babelfish.yahoo.com)
Source: http://www.micropoll.com/akira/mpresult/501697-116746
http://www.java.net
Source: http://www.grailspodcast.com/
5
5

6. Reason: Language Features
• Closures
• Productivity
• Runtime metaprogramming
• Clarity
• Compile-time metaprogramming
• Maintainability
• Grape modules
• Quality
• Builders
• Fun
• DSL friendly
6
6

7. Reason: Testing
• Support for Testing DSLs and • Productivity
BDD style tests
• Clarity
• Built-in assert, power asserts
• Maintainability
• Built-in testing
• Quality
• Built-in mocks
• Fun
• Metaprogramming eases testing
pain points • Shareability
7
7

8. Myth: Dynamic typing == No IDE support
• Completion through inference
• Code analysis
• Seamless debugging
• Seamless refactoring
• DSL completion
8
8

9. Myth: Scripting == Non-professional
• Analysis tools
• Coverage tools
• Testing support
9
9

10. Java Groovy
import
java.util.List;
import
java.util.ArrayList;
class
Erase
{
private
List
removeLongerThan(List
strings,
int
length)
{
List
result
=
new
ArrayList();
for
(int
i
=
0;
i
<
strings.size();
i++)
{
String
s
=
(String)
strings.get(i);
if
(s.length()
<=
length)
{
result.add(s);
names
=
["Ted",
"Fred",
"Jed",
"Ned"]
} println
names
}
return
result; shortNames
=
names.findAll{
it.size()
<=
3
}
}
public
static
void
main(String[]
args)
{ println
shortNames.size()
List
names
=
new
ArrayList();
names.add("Ted");
names.add("Fred");
shortNames.each{
println
it
}
names.add("Jed");
names.add("Ned");
System.out.println(names);
Erase
e
=
new
Erase();
List
shortNames
=
e.removeLongerThan(names,
3);
System.out.println(shortNames.size());
for
(int
i
=
0;
i
<
shortNames.size();
i++)
{
String
s
=
(String)
shortNames.get(i);
System.out.println(s);
}
}
}
10
10

11. Java Groovy
import
org.w3c.dom.Document;
import
org.w3c.dom.NodeList;
import
org.w3c.dom.Node;
import
org.xml.sax.SAXException;
import
javax.xml.parsers.DocumentBuilderFactory;
import
javax.xml.parsers.DocumentBuilder;
import
javax.xml.parsers.ParserConfigurationException;
import
java.io.File;
import
java.io.IOException; def
p
=
new
XmlParser()
public
class
FindYearsJava
{ def
records
=
p.parse("records.xml")
public
static
void
main(String[]
args)
{
DocumentBuilderFactory
builderFactory
=
DocumentBuilderFactory.newInstance();
records.car.each
{
try
{
DocumentBuilder
builder
=
builderFactory.newDocumentBuilder();
println
"year
=
${it.@year}"
Document
document
=
builder.parse(new
File("records.xml")); }
NodeList
list
=
document.getElementsByTagName("car");
for
(int
i
=
0;
i
<
list.getLength();
i++)
{
Node
n
=
list.item(i);
Node
year
=
n.getAttributes().getNamedItem("year");
System.out.println("year
=
"
+
year.getTextContent());
}
}
catch
(ParserConfigurationException
e)
{
e.printStackTrace();
}
catch
(SAXException
e)
{
e.printStackTrace();
}
catch
(IOException
e)
{
e.printStackTrace();
}
}
}
11
11

12. Java Groovy
public
final
class
Punter
{
//
...
private
final
String
first;
@Override
private
final
String
last;
public
boolean
equals(Object
obj)
{
if
(this
==
obj)
public
String
getFirst()
{
return
true;
return
first;
if
(obj
==
null)
}
return
false;
if
(getClass()
!=
obj.getClass()) @Immutable
class
Punter
{
public
String
getLast()
{
return
false;
return
last;
Punter
other
=
(Punter)
obj;
String
first,
last
}
if
(first
==
null)
{
if
(other.first
!=
null)
}
@Override
return
false;
public
int
hashCode()
{
}
else
if
(!first.equals(other.first))
final
int
prime
=
31;
return
false;
int
result
=
1;
if
(last
==
null)
{
result
=
prime
*
result
+
((first
==
null)
if
(other.last
!=
null)
?
0
:
first.hashCode());
return
false;
result
=
prime
*
result
+
((last
==
null)
}
else
if
(!last.equals(other.last))
?
0
:
last.hashCode());
return
false;
return
result;
return
true;
}
}
public
Punter(String
first,
String
last)
{
@Override
this.first
=
first;
public
String
toString()
{
this.last
=
last;
return
"Punter(first:"
+
first
}
+
",
last:"
+
last
+
")";
//
...
}
}
12
12

13. Java Groovy
public class CustomException extends RuntimeException {
public CustomException() {
super(); @InheritConstructors
}
class CustomException
public CustomException(String message) { extends RuntimeException { }
super(message);
}
public CustomException(String message, Throwable cause) {
super(message, cause);
}
public CustomException(Throwable cause) {
super(cause);
}
}
13
13

14. Groovy
@Grab('com.google.collections:google-­‐collections:1.0')
import
com.google.common.collect.HashBiMap @Grab('org.gcontracts:gcontracts:1.0.2') Groovy 1.8+
import
org.gcontracts.annotations.*
HashBiMap
fruit
=
[grape:'purple',
lemon:'yellow',
lime:'green']
@Invariant({
first
!=
null
&&
last
!=
null
})
assert
fruit.lemon
==
'yellow' class
Person
{
assert
fruit.inverse().yellow
==
'lemon'
String
first,
last
@Requires({
delimiter
in
['.',
',',
'
']
})
@Grab('org.codehaus.gpars:gpars:0.10')
@Ensures({
result
==
first+delimiter+last
})
import
groovyx.gpars.agent.Agent
String
getName(String
delimiter)
{
first
+
delimiter
+
last
withPool(5)
{
}
def
nums
=
1..100000
}
println
nums.parallel.
map{
it
**
2
}.
new
Person(first:
'John',
last:
'Smith').getName('.')
filter{
it
%
7
==
it
%
5
}.
filter{
it
%
3
==
0
}.
reduce{
a,
b
-­‐>
a
+
b
}
}
Groovy and Gpars both OSGi compliant
14
14

15. Plugin Tutorial: World of WarCraft...
• http://confluence.atlassian.com/display/CONFDEV/
WoW+Macro+explanation
15
15

16. ...Plugin Tutorial: World of WarCraft...
• Normal instructions for gmaven:
http://gmaven.codehaus.org/
...
<plugin>
<groupId>org.codehaus.gmaven</groupId>
<artifactId>gmaven-­‐plugin</artifactId>
<version>1.2</version>
<configuration>...</configuration>
<executions>...</executions>
<dependencies>...</dependencies>
</plugin>
...
16
16

17. ...Plugin Tutorial: World of WarCraft...
package
com.atlassian.confluence.plugins.wowplugin; ...
public
String
getName()
{
import
java.io.Serializable;
return
name;
import
java.util.Arrays;
}
import
java.util.List;
public
String
getSpec()
{
/**
return
spec;
*
Simple
data
holder
for
basic
toon
information
}
*/
public
final
class
Toon
implements
Comparable,
Serializable
public
int
getGearScore()
{
{
return
gearScore;
private
static
final
String[]
CLASSES
=
{
}
"Warrior",
"Paladin",
public
List
getRecommendedRaids()
{
"Hunter",
return
recommendedRaids;
"Rogue",
}
"Priest",
"Death
Knight",
public
String
getClassName()
{
"Shaman",
return
className;
"Mage",
}
"Warlock",
"Unknown",
//
There
is
no
class
with
ID
10.
Weird.
public
int
compareTo(Object
o)
"Druid"
{
};
Toon
otherToon
=
(Toon)
o;
private
final
String
name;
if
(otherToon.gearScore
-­‐
gearScore
!=
0)
private
final
String
spec;
return
otherToon.gearScore
-­‐
gearScore;
private
final
int
gearScore;
private
final
List
recommendedRaids;
return
name.compareTo(otherToon.name);
private
final
String
className;
}
public
Toon(String
name,
int
classId,
String
spec,
int
gearScore,
String...
recommendedRaids)
private
String
toClassName(int
classIndex)
{
{
this.className
=
toClassName(classId
-­‐
1);
if
(classIndex
<
0
||
classIndex
>=
CLASSES.length)
this.name
=
name;
return
"Unknown:
"
+
classIndex
+
1;
this.spec
=
spec;
else
this.gearScore
=
gearScore;
return
CLASSES[classIndex];
this.recommendedRaids
=
Arrays.asList(recommendedRaids);
}
} }
...
17
17

18. ...Plugin Tutorial: World of WarCraft...
package
com.atlassian.confluence.plugins.gwowplugin
class
Toon
implements
Serializable
{
private
static
final
String[]
CLASSES
=
[
"Warrior",
"Paladin",
"Hunter",
"Rogue",
"Priest",
"Death
Knight",
"Shaman",
"Mage",
"Warlock",
"Unknown",
"Druid"] 83 -> 17
String
name
int
classId
String
spec
int
gearScore
def
recommendedRaids
String
getClassName()
{
classId
in
0..<CLASSES.length
?
CLASSES[classId
-­‐
1]
:
"Unknown:
"
+
classId
}
}
18
18

19. ...Plugin Tutorial: World of WarCraft...
package com.atlassian.confluence.plugins.wowplugin; ... ...
public boolean isInline() { return false; } try {
import com.atlassian.cache.Cache; url = String.format("http://xml.wow-heroes.com/xml-guild.php?z=%s&r=%s&g=%s",
import com.atlassian.cache.CacheManager; public boolean hasBody() { return false; } URLEncoder.encode(zone, "UTF-8"),
import com.atlassian.confluence.util.http.HttpResponse; URLEncoder.encode(realmName, "UTF-8"),
import com.atlassian.confluence.util.http.HttpRetrievalService; public RenderMode getBodyRenderMode() { URLEncoder.encode(guildName, "UTF-8"));
import com.atlassian.renderer.RenderContext; return RenderMode.NO_RENDER; } catch (UnsupportedEncodingException e) {
import com.atlassian.renderer.v2.RenderMode; } throw new MacroException(e.getMessage(), e);
import com.atlassian.renderer.v2.SubRenderer; }
import com.atlassian.renderer.v2.macro.BaseMacro; public String execute(Map map, String s, RenderContext renderContext) throws MacroException {
import com.atlassian.renderer.v2.macro.MacroException; String guildName = (String) map.get("guild"); Cache cache = cacheManager.getCache(this.getClass().getName() + ".toons");
import org.dom4j.Document; String realmName = (String) map.get("realm");
import org.dom4j.DocumentException; String zone = (String) map.get("zone"); if (cache.get(url) != null)
import org.dom4j.Element; if (zone == null) zone = "us"; return (List<Toon>) cache.get(url);
import org.dom4j.io.SAXReader;
StringBuilder out = new StringBuilder("||Name||Class||Gear Score");
try {
for (int i = 0; i < SHORT_RAIDS.length; i++) {
import java.io.IOException; List<Toon> toons = retrieveAndParseFromWowArmory(url);
out.append("||").append(SHORT_RAIDS[i].replace('/', 'n'));
import java.io.InputStream; cache.put(url, toons);
}
import java.io.UnsupportedEncodingException; return toons;
out.append("||n");
import java.net.URLEncoder; }
import java.util.*; catch (IOException e) {
List<Toon> toons = retrieveToons(guildName, realmName, zone);
throw new MacroException("Unable to retrieve information for guild: " + guildName + ", " + e.toString());
/** for (Toon toon : toons) { }
* Inserts a table of a guild's roster of 80s ranked by gear level, with recommended raid instances. The data for catch (DocumentException e) {
* the macro is grabbed from http://wow-heroes.com. Results are cached for $DEFAULT_CACHE_LIFETIME to reduce
out.append("| "); throw new MacroException("Unable to parse information for guild: " + guildName + ", " + e.toString());
* load on the server. try { }
* <p/> }
String url = String.format("http://xml.wow-heroes.com/index.php?zone=%s&server=%s&name=%s",
* Usage: {guild-gear|realm=Nagrand|guild=A New Beginning|zone=us} URLEncoder.encode(zone, "UTF-8"),
* <p/> URLEncoder.encode(realmName, "UTF-8"), private List<Toon> retrieveAndParseFromWowArmory(String url) throws IOException, DocumentException {
* Problems: URLEncoder.encode(toon.getName(), "UTF-8")); List<Toon> toons = new ArrayList<Toon>();
* <p/> out.append("["); out.append(toon.getName()); HttpResponse response = httpRetrievalService.get(url);
* * wow-heroes reports your main spec, but whatever gear you logged out in. So if you out.append("|"); out.append(url); out.append("]");
logged out in off-spec gear
* your number will be wrong } InputStream responseStream = response.getResponse();
* * gear score != ability. l2play nub. catch (UnsupportedEncodingException e) { try {
*/ out.append(toon.getName()); SAXReader reader = new SAXReader();
public class GuildGearMacro extends BaseMacro { } Document doc = reader.read(responseStream);
private HttpRetrievalService httpRetrievalService; List toonsXml = doc.selectNodes("//character");
private SubRenderer subRenderer; out.append(" | "); for (Object o : toonsXml) {
private CacheManager cacheManager; out.append(toon.getClassName()); Element element = (Element) o;
out.append(" ("); toons.add(new Toon(element.attributeValue("name"), Integer.parseInt(element.attributeValue("classId")),
private static final String[] RAIDS = { out.append(toon.getSpec()); element.attributeValue("specName"),
"Heroics", out.append(")"); Integer.parseInt(element.attributeValue("score")), element.attributeValue("suggest").split(";")));
"Naxxramas 10", // and OS10 out.append("|"); }
"Naxxramas 25", // and OS25/EoE10 out.append(toon.getGearScore());
"Ulduar 10", // and EoE25 boolean found = false; Collections.sort(toons);
"Onyxia 10", }
"Ulduar 25", // and ToTCr10 for (String raid : RAIDS) { finally {
"Onyxia 25", if (toon.getRecommendedRaids().contains(raid)) { responseStream.close();
"Trial of the Crusader 25", out.append("|(!)"); }
"Icecrown Citadel 10" found = true; return toons;
}; } else { }
out.append("|").append(found ? "(x)" : "(/)");
private static final String[] SHORT_RAIDS = { } public void setHttpRetrievalService(HttpRetrievalService httpRetrievalService) {
"H", } this.httpRetrievalService = httpRetrievalService;
"Naxx10/OS10", out.append("|n"); }
"Naxx25/OS25/EoE10", }
"Uld10/EoE25", public void setSubRenderer(SubRenderer subRenderer) {
"Ony10", return subRenderer.render(out.toString(), renderContext); this.subRenderer = subRenderer;
"Uld25/TotCr10", } }
"Ony25",
"TotCr25", private List<Toon> retrieveToons(String guildName, String realmName, String zone) public void setCacheManager(CacheManager cacheManager) {
"IC" throws MacroException { this.cacheManager = cacheManager;
}; String url = null; }
... ... }
19
19

20. ...Plugin Tutorial: World of WarCraft...
package
com.atlassian.confluence.plugins.gwowplugin ...
toons.each
{
toon
-­‐>
import
com.atlassian.cache.CacheManager
def
url
=
"http://xml.wow-­‐heroes.com/index.php?zone=${enc
zone}&server=${enc
map.realm}&name=${enc
toon.name}"
import
com.atlassian.confluence.util.http.HttpRetrievalService
out.append("|
[${toon.name}|${url}]
|
$toon.className
($toon.spec)|
$toon.gearScore")
import
com.atlassian.renderer.RenderContext
boolean
found
=
false
import
com.atlassian.renderer.v2.RenderMode
RAIDS.each
{
raid
-­‐>
import
com.atlassian.renderer.v2.SubRenderer
if
(raid
in
toon.recommendedRaids)
{
import
com.atlassian.renderer.v2.macro.BaseMacro
out.append("|(!)")
import
com.atlassian.renderer.v2.macro.MacroException
found
=
true
}
else
{
/**
out.append("|").append(found
?
"(x)"
:
"(/)")
*
Inserts
a
table
of
a
guild's
roster
of
80s
ranked
by
gear
level,
with
recommended
raid
}
*
instances.
The
data
for
the
macro
is
grabbed
from
http://wow-­‐heroes.com.
Results
are
} 200 -> 90
*
cached
for
$DEFAULT_CACHE_LIFETIME
to
reduce
load
on
the
server.
out.append("|n")
*
<p/>
}
*
Usage:
{guild-­‐gear:realm=Nagrand|guild=A
New
Beginning|zone=us}
subRenderer.render(out.toString(),
renderContext)
*/
}
class
GuildGearMacro
extends
BaseMacro
{
HttpRetrievalService
httpRetrievalService
private
retrieveToons(String
guildName,
String
realmName,
String
zone)
throws
MacroException
{
SubRenderer
subRenderer
def
url
=
"http://xml.wow-­‐heroes.com/xml-­‐guild.php?z=${enc
zone}&r=${enc
realmName}&g=${enc
guildName}"
CacheManager
cacheManager
def
cache
=
cacheManager.getCache(this.class.name
+
".toons")
if
(!cache.get(url))
cache.put(url,
retrieveAndParseFromWowArmory(url))
private
static
final
String[]
RAIDS
=
[
return
cache.get(url)
"Heroics",
"Naxxramas
10",
"Naxxramas
25",
"Ulduar
10",
"Onyxia
10",
}
"Ulduar
25",
"Onyxia
25",
"Trial
of
the
Crusader
25",
"Icecrown
Citadel
10"]
private
static
final
String[]
SHORT_RAIDS
=
[
private
retrieveAndParseFromWowArmory(String
url)
{
"H",
"Naxx10/OS10",
"Naxx25/OS25/EoE10",
"Uld10/EoE25",
"Ony10",
def
toons
"Uld25/TotCr10",
"Ony25",
"TotCr25",
"IC"]
httpRetrievalService.get(url).response.withReader
{
reader
-­‐>
toons
=
new
XmlSlurper().parse(reader).guild.character.collect
{
boolean
isInline()
{
false
}
new
Toon(
boolean
hasBody()
{
false
}
name:
it.@name,
RenderMode
getBodyRenderMode()
{
RenderMode.NO_RENDER
}
classId:
it.@classId.toInteger(),
spec:
it.@specName,
String
execute(Map
map,
String
s,
RenderContext
renderContext)
throws
MacroException
{
gearScore:
it.@score.toInteger(),
def
zone
=
map.zone
?:
"us"
recommendedRaids:
it.@suggest.toString().split(";"))
def
out
=
new
StringBuilder("||Name||Class||Gear
Score")
}
SHORT_RAIDS.each
{
out.append("||").append(it.replace('/',
'n'))
}
}
out.append("||n")
toons.sort{
a,
b
-­‐>
a.gearScore
==
b.gearScore
?
a.name
<=>
b.name
:
a.gearScore
<=>
b.gearScore
}
}
def
toons
=
retrieveToons(map.guild,
map.realm,
zone)
...
def
enc(s)
{
URLEncoder.encode(s,
'UTF-­‐8')
}
} 20
20

21. ...Plugin Tutorial: World of WarCraft...
{groovy-wow-item:1624} {groovy-guild-gear:realm=Kirin Tor|guild=Faceroll Syndicate|zone=us}
21
21

22. ...Plugin Tutorial: World of WarCraft...
> atlas-mvn clover2:setup test clover2:aggregate clover2:clover
22
22

23. ...Plugin Tutorial: World of WarCraft
narrative
'segment
flown',
{
package
com.atlassian.confluence.plugins.gwowplugin
as_a
'frequent
flyer'
i_want
'to
accrue
rewards
points
for
every
segment
I
fly'
class
ToonSpec
extends
spock.lang.Specification
{
so_that
'I
can
receive
free
flights
for
my
dedication
to
the
airline'
def
"successful
name
of
Toon
given
classId"()
{ }
scenario
'segment
flown',
{
given:
given
'a
frequent
flyer
with
a
rewards
balance
of
1500
points'
def
t
=
new
Toon(classId:
thisClassId)
when
'that
flyer
completes
a
segment
worth
500
points'
then
'that
flyer
has
a
new
rewards
balance
of
2000
points'
expect: }
t.className
==
name
scenario
'segment
flown',
{
given
'a
frequent
flyer
with
a
rewards
balance
of
1500
points',
{
where:
flyer
=
new
FrequentFlyer(1500)
name
|
thisClassId
}
"Hunter"
|
3
when
'that
flyer
completes
a
segment
worth
500
points',
{
"Rogue"
|
4
flyer.fly(new
Segment(500))
}
"Priest"
|
5
then
'that
flyer
has
a
new
rewards
balance
of
2000
points',
{
flyer.pointsBalance.shouldBe
2000
}
}
}•
}
• Testing with Spock • Or Cucumber, EasyB, JBehave,
23
23

24. Scripting on the fly...
24
24

25. ...Scripting on the fly...
25
25

26. ...Scripting on the fly
26
26

27. 27
27