Mega Code Archive
Simple demonstrations of the Collections utilities
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// : c11:Utilities.java
// Simple demonstrations of the Collections utilities.
// From 'Thinking in Java, 3rd ed.' (c) Bruce Eckel 2002
// www.BruceEckel.com. See copyright notice in CopyRight.txt.
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.Enumeration;
import java.util.List;
import java.util.Vector;
public class Utilities {
public static void main(String[] args) {
List list = Arrays.asList("one Two three Four five six one".split(" "));
System.out.println(list);
System.out.println("max: " + Collections.max(list));
System.out.println("min: " + Collections.min(list));
AlphabeticComparator comp = new AlphabeticComparator();
System.out.println("max w/ comparator: " + Collections.max(list, comp));
System.out.println("min w/ comparator: " + Collections.min(list, comp));
List sublist = Arrays.asList("Four five six".split(" "));
System.out.println("indexOfSubList: "
+ Collections.indexOfSubList(list, sublist));
System.out.println("lastIndexOfSubList: "
+ Collections.lastIndexOfSubList(list, sublist));
Collections.replaceAll(list, "one", "Yo");
System.out.println("replaceAll: " + list);
Collections.reverse(list);
System.out.println("reverse: " + list);
Collections.rotate(list, 3);
System.out.println("rotate: " + list);
List source = Arrays.asList("in the matrix".split(" "));
Collections.copy(list, source);
System.out.println("copy: " + list);
Collections.swap(list, 0, list.size() - 1);
System.out.println("swap: " + list);
Collections.fill(list, "pop");
System.out.println("fill: " + list);
List dups = Collections.nCopies(3, "snap");
System.out.println("dups: " + dups);
// Getting an old-style Enumeration:
Enumeration e = Collections.enumeration(dups);
Vector v = new Vector();
while (e.hasMoreElements())
v.addElement(e.nextElement());
// Converting an old-style Vector
// to a List via an Enumeration:
ArrayList arrayList = Collections.list(v.elements());
System.out.println("arrayList: " + arrayList);
}
} ///:~
class AlphabeticComparator implements Comparator {
public int compare(Object o1, Object o2) {
String s1 = (String) o1;
String s2 = (String) o2;
return s1.toLowerCase().compareTo(s2.toLowerCase());
}
} ///:~
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