再练

import java.util.*;//。
import java.util.Map.Entry;
 
class Student implements Comparable <Student>
/*定义一个Student类覆写hashCode和equals
方法使其具有比较性继承Comparable接口实现compaeTo方法使其具有一定的排序性*/
{  
 //定义三个私有成员
 private String name;                                          
 private int num;                                  
 private String addrees;
 Student (String name,int num,String addrees)//构造函数
 {
  this.name=name;
  this.num=num;
  this.addrees=addrees;
 }
 
 public int compareTo(Student s)//实现Comparable接口中的compareTo方法
 {
  int a= this.name.compareTo(s.name);
  if (a==0)
  return new Integer(this.num).compareTo(new Integer(s.num));
  return a;
 }
 public   String getName()
 {
  return name;
 }
 public  int getNum()
 {
  
  return num;
 }
 public  String getAddrees()
 {
  
  return addrees;
 }
 public int hashCode()//覆写hashCode方法
 {
  return name.hashCode()+num*34;
 }
 public boolean equals(Object obj)//覆写equals方法
 {
  if (!(obj instanceof Student))
  {
   throw new ClassCastException("失败");
  }
  Student s=(Student)obj;
  return this.name.equals(s.name)&&this.num==s.num&&this.addrees.equals(s.addrees);
 }
 public String toString()
 {
  return "学号: "+num+" 姓名: "+name+" 地址: "+addrees;
 }
 
}
public class MapTest {

 

 /**
  * @param args
  */
 public static void main(String[] args) {
  // TODO Auto-generated method stub
  HashMap<Student,Integer> map=new HashMap<Student,Integer>();
  map.put(new Student("Tom",001,"Baijing"), 53);
  map.put(new Student("Jam",002,"Baijing"), 87);
  map.put(new Student("Joy",003,"Baijing"), 96);
  map.put(new Student("Pak",004,"Baijing"), 49);
  
  //第一种取出方式 keySet方法
  Set<Student> keyset=map.keySet();
  Iterator it =keyset.iterator();
  while (it.hasNext())
  {
   Student st=(Student) it.next();
   Integer score=map.get(st);
   System.out.println(st+":::"+score);
   
  }
        //第二种取出方式 entrySet方法
  Set<Map.Entry<Student,Integer>> entryset=map.entrySet();
  Iterator<Map.Entry<Student,Integer>> its =entryset.iterator();
  while (its.hasNext())
  {
   Map.Entry<Student,Integer> mm=its.next();
   Student stu= mm.getKey();
   
   Integer sco=mm.getValue();
   System.out.println(stu+" 成绩： "+sco);
  }
  
 }

}