TreeMap练习：对学生对象的姓名进行升序排序

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package map;

import java.util.*;
public class MapDemo4 {

/**
* @TreeMap练习
*
* 对学生对象的姓名进行升序排序
*
* 因为数据是以键值对形式存在的。
* 所以要使用可以排序的Map集合。TreeMap。
*
*
*/
public static void main(String[] args) {
  TreeMap<Student,String> tm = new TreeMap<Student,String>(new StuNameComparator());

  tm.put(new Student("blisi3",23),"nanjing");
  tm.put(new Student("lisi1",21),"beijing");
  tm.put(new Student("lisi1",21),"tianjing");
  tm.put(new Student("alisi4",24),"wuhan");
  tm.put(new Student("lisi2",22),"shanghai");

  Set<Map.Entry<Student, String>> entrySet = tm.entrySet();

  Iterator<Map.Entry<Student, String>> it = entrySet.iterator();

  while(it.hasNext()){
   Map.Entry<Student, String> me = it.next();

   Student stu = me.getKey();
   String addr = me.getValue();
   System.out.println(stu+"..."+addr);
  }

}

class StuNameComparator implements Comparator<Student>{
public int compare(Student s1,Student s2){
  int num = s1.getName().compareTo(s2.getName());
  if(num==0)
   return new Integer(s1.getAge()).compareTo(new Integer(s2.getAge()));
  return num;

}
}

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