将字符串按长度进行倒序排序——传入Collections.reverseOrder一个已有比较器

/*

* 将字符串按照长度进行倒序排序

*/

package collectionsdemo;

import java.util.Collections;

import java.util.Comparator;

import java.util.TreeSet;

public class CollectionsDemo implements Comparator <String>{

/**

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

demo();

}

@Override

public int compare(String o1, String o2) {

// TODO Auto-generated method stub

int temp=o1.length()-o2.length();

return temp==0?o1.compareTo(o2):temp;

}

private static void demo() {

// TODO Auto-generated method stub

TreeSet ts=new TreeSet(Collections.reverseOrder(new CollectionsDemo()));

ts.add("dsadas");

ts.add("asss");

ts.add("abc");

ts.add("zzz");

System.out.println(ts);

}

}