集合框架-TreeSet-Comparator比较器练习（字符串长度排序）

 1 package cn.itcast.p5.treeset.test;
 2
 3 import java.util.Iterator;
 4 import java.util.TreeSet;
 5
 6 import cn.itcast.p5.comparator.ComparatorByLen;
 7 /*
 8  * 对字符串进行长度排序
 9  */
10 public class TreeSetTest {
11
12     public static void main(String[] args) {
13         // TODO Auto-generated method stub
14         TreeSet ts = new TreeSet(new ComparatorByLen());
15
16         ts.add("aaaaa");
17         ts.add("zz");
18         ts.add("nbaq");
19         ts.add("cba");
20         ts.add("abc");
21
22         Iterator it = ts.iterator();
23
24         while(it.hasNext()) {
25             System.out.println(it.next());
26         }
27     }
28
29 }

Test

 1 package cn.itcast.p5.comparator;
 2
 3 import java.util.Comparator;
 4
 5 public class ComparatorByLen implements Comparator {
 6
 7     @Override
 8     public int compare(Object o1, Object o2) {
 9         // TODO Auto-generated method stub
10         String s1 = (String)o1;
11         String s2 = (String)o2;
12         int temp = s1.length()-s2.length();
13
14         return temp==0?s1.compareTo(s2):temp;
15
16     }
17
18 }

ComparatorByLen