TreeMap排序Comparator()重写

package map_;

import java.util.Comparator;
import java.util.TreeMap;

/*
 *   @author  YAM
 */
public class TreeMap01 {
 public static void main(String[] args) {

  TreeMap treeMap = new TreeMap(new Comparator() {
   @Override
   public int compare(Object o1, Object o2) {
  //  return ((String) o1).compareTo((String) o2);
    return ((String) o1).length() - ((String) o2).length();
    // 长度相同 返回0 即认为相等， 会发生覆盖
   }
  });

  treeMap.put("jack","杰克");
  treeMap.put("tom", "汤姆");
  treeMap.put("kristina", "克瑞斯提诺");
  treeMap.put("smith", "斯密斯");
  treeMap.put("hsp", "韩顺平");//length=3与tom相同加入不了，覆盖汤姆

  System.out.println("treemap="+treeMap);

 }
}