descendsort.java

高质量Java程序设计 源代码

package net.betterjava.collection.sort;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.List;

class StringDescendComparator implements Comparator {
	public int compare(Object o1, Object o2) {
		String s1 = (String) o1;
		String s2 = (String) o2;
		return s1.compareTo(s2) * (-1);
	}

	public boolean equals(Object obj) {
		Comparator com = (Comparator) obj;
		return true;
	}
}

public class DescendSort {

	public static void main(String[] args) {
		List list = new ArrayList();
		for (int i = 0; i < 6; i++) {
			list.add(String.valueOf(Math.random()));
		}

		//before sort
		Iterator it = list.iterator();
		System.out.println("before sort");
		while (it.hasNext()) {
			System.out.println(it.next());
		}

		Comparator com = new StringDescendComparator();
		Collections.sort(list, Collections.reverseOrder());

		//after sort
		it = list.iterator();
		System.out.println("after sort");
		while (it.hasNext()) {
			System.out.println(it.next());
		}
	}
}