As most of you already know (if you don’t, never mind, I will forgive you :D), I’m going to give a lightning talk in the Free Java Dev room at FOSDEM about Groovy. The title will be “Groovy: the cool side of java” and basically it will be an hand-on speech. No slide, just code. I will start from a simple Java code and I will rewrite it in Groovy. During the demo/live I will give some basics explanation about how is groovy working and we will see the power and the value that Groovy add at the top of JVM compared with a static language like Java.
Here the code that I wrote:
import java.util.ArrayList; import java.util.List; import java.util.Collections; class TestJava{ public static void main(String[] args) { new DoStuffs().doIt(); } } class DoStuffs{ public void doIt(){ List al = new ArrayList(); System.out.println("* Initial size of"+al.getClass()+" : " + al.size() + " with elements "+al); al.add("this"); al.add("is"); al.add("just"); al.add("test"); System.out.println("* Final size of"+al.getClass()+" : " + al.size() + " with elements "+al); System.out.println("* Let's add some stuffs"); al.add(2,"a"); al.add(3,"cool"); System.out.println("* Done "+al); System.out.println(""); System.out.println("- Before ordering"+al); Collections.sort(al); System.out.println("- After ordering "+al); System.out.println(""); List al2 = al.subList(2,4); System.out.println("- Sublisting "+al2); System.out.println(""); if(al.size() > 0){ for (int i=0; i< al.size(); i++) { al.set(i, al.get(i)+" \\o/ "); } System.out.println("Let's show the element in the reverse order: "); for (int i=al.size()-1; i>=0; i--){ System.out.println("<"+i+"> "+al.get(i)); } } if(al != null){ List sub = new ArrayList(); for (int i=0; i< al.size(); i++) { String el = (String) al.get(i); if(el.contains("t")) { sub.add(al.get(i)); } } System.out.println("- After grep "+ sub); } } }