Why Groovy is a nicer and more productive language than Java.

1. Getting Groovy

2. JVM Languages Java JRuby Jython

3. JVM Languages Java JRuby Jython

4. JVM Languages Java JRuby Jython Groovy

5. Two Worlds Collide Java Perl

6. Two Worlds Collide Java Perl

7. Two Worlds Collide Java Perl

8. Two Worlds Collide Java Perl

9. Slurping files in Perl

10. Slurping files in Perl my $fh = open '<', $filename; local $/ = undef; my $contents = <$fh>;

11. Slurping files in Perl my $fh = open '<', $filename; local $/ = undef; my $contents = <$fh>; Slurping in Ruby

12. Slurping files in Perl my $fh = open '<', $filename; local $/ = undef; my $contents = <$fh>; Slurping in Ruby file = File.open(filename, "rb") contents = file.read

13. Java?

14. Java? StringBuilder contents = new StringBuilder(); try { BufferedReader input = new BufferedReader(new FileReader(aFile)); try { String line = null; while ( (line = input.readLine()) != null) { contents.append(line); contents.append(lineSeparator); } } finally { input.close(); } } catch (IOException ex) { ex.printStackTrace(); } ... = contents.toString();

15. Java’s True Character

16. Java’s True Character

17. What would Groovy do?

18. What would Groovy do? def contents = new File(filename) …

19. What would Groovy do? def contents = new File(filename) .text

20. XML Parsing <langs type="current"> <language>Perl</language> <language>Java</language> <language>Groovy</language></langs>

21. XML Parsing <langs type="current"> <language>Perl</language> <language>Java</language> <language>Groovy</language></langs> import org.w3c.dom.*; import org.xml.sax.SAXException; import javax.xml.parsers.*; import java.io.IOException;

22. XML Parsing <langs type="current"> <language>Perl</language> <language>Java</language> <language>Groovy</language></langs> public class ParseXml { public static void main(String[] args) { DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance(); try { DocumentBuilder db = dbf.newDocumentBuilder(); Document doc = db.parse(“langs.xml"); Element langs = doc.getDocumentElement(); System.out.println("type = " + langs.getAttribute("type")); NodeList list = langs.getElementsByTagName("language"); for(int i=0; i < list.getLength(); i++) { Element language = (Element) list.item(i); System.out.println(language.getTextContent()); } } catch(ParserConfigurationException pce) { pce.printStackTrace(); } catch(SAXException se) { se.printStackTrace(); } catch(IOException ioe) { ioe.printStackTrace(); } } } }

23. XML Parsing in Groovy <langs type="current"> <language>Perl</language> <language>Java</language> <language>Groovy</language></langs>

24. XML Parsing in Groovy <langs type="current"> <language>Perl</language> <language>Java</language> <language>Groovy</language></langs> def langs = new XmlSlurper().parse("langs.xml") println langs.@type langs.language.each { elem -> println elem }

25. XML Parsing in Groovy <langs type="current"> <language>Perl</language> <language>Java</language> <language>Groovy</language></langs> def langs = new XmlSlurper().parse("langs.xml") println langs.@type langs.language.each { println it }

26. Configuration foo { port = 80 bar { baz { some.thing = "burp" } } } def config = new ConfigSlurper().parse(...) def config = new ConfigSlurper() .parse(new File("config.groovy").toURL()) assert config.foo.port == 80 assert config.foo.bar.baz.some.thing == "burp"

27. Environment Configuration foo.bar = "baz" something.else = 99 environments { development { port = 8181 db = "devdb" } test { port = 8080 db = "testdb" } production { port = 80 db = "proddb" } } ConfigSlurper("production")