On regarde un implantation simple des Collections fait par Watt et Brown et modifié par Guy Lapalme. Les fichiers sont trouvés dans CollectionsSimplifiees.
Voir aussi le PDF ShowCollections.pdf. Il y a un démo applet avec source.
import java.util.*; import java.io.*; public class ListExample { public static void main(String args[]) { List l1 = new ArrayList(); try { String str; String [] words; BufferedReader in = new BufferedReader(new FileReader(args[0])); while ((str = in.readLine()) != null) { words = str.split(" "); l1.addAll(Arrays.asList(words)); } } catch (IOException e) { System.err.println(e); return; } List l2 = new ArrayList(l1); //l2.addAll(l1); String s = args[0]; List l3 = l1.subList(0,4); System.out.println("l1: " + l1); System.out.println("l2: " +l2); System.out.println("l3: " + l3); Collections.shuffle(l1,new Random()); System.out.println("l1 apres shuffle: " + l1); System.out.println("l2 apres shuffle: " + l2); System.out.println("l3 apres shuffle: " + l3); } }
import java.util.*; import java.io.*; public class MapExample { public static void main(String args[]) { Map m = new TreeMap(); try { String str; String [] words; BufferedReader in = new BufferedReader(new FileReader(args[0])); while ((str = in.readLine()) != null) { words = str.split(" "); for (int i=0;i<words.length;i++) { if (m.containsKey(words[i])) { m.put(words[i],new Integer((Integer)m.get(words[i])+1)); } else { m.put(words[i],new Integer(1)); } } } } catch (IOException e) { System.err.println(e); return; } System.out.println("Map: " + m); } }