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import java.util.*;
/*
* 需求：每一个学生都有其对应的归属地
* 学生：student 地址：String
* 学生属性：姓名，年龄
* 姓名和年龄相同视为同一个学生
* 保证学生的唯一性
* 将学生作为key，地址作为value存放。。。。因为一个地方可以有多个学生
* 1.描述学生对象
* 2.定义map集合
* 3.获取map集合中的元素
* */
class MapText_学生归属地联系
{
public static void main(String[] args)
{
//Student stu1= new Student("zhangsan",20);
//Student stu2= new Student("lisi",30);
//Student stu3= new Student("wangwu",22);
//Student stu4= new Student("zhaoliu",27);
HashMap<Student,String> hm = new HashMap<Student,String>();
hm.put(new Student("zhangsan",20),"beijing");
hm.put(new Student("lisi",30),"nanjing");
hm.put( new Student("wangwu",22),"jilin");
hm.put(new Student("zhaoliu",27),"shanghai");
Set<Student> keySet = hm.keySet();
Iterator<Student> it = keySet.iterator();
while(it.hasNext())
{
Student stu = it.next();
String addr = hm.get(stu);
System.out.println("key:"+stu+"..value:"+addr);
}
}
}
class Student implements Comparable<Student>
{
private String name;
private int age;
Student(String name,int age)
{
this.name=name;
this.age=age;
}
public int hashCode()
{
return name.hashCode()+age*34;
}
public boolean equals(Object obj)
{
if(!(obj instanceof Student))
throw new ClassCastException("类型不匹配");
Student s = (Student)obj;
return this.name.equals(s.name)&&this.age == s.age;
}
/*
public int compareTo(Object obj)
{
if(!(obj instanceof Student))
throw new RuntimeException("不是学生对象，滚粗");
Student s = obj;
if(this.age==s.age)
return this.name.compareTo(s.name);
return 1;
}
*/
public int compareTo(Student s)
{
int num = new Integer(this.age).compareTo(new Integer(s.age));
if(num == 0)
return this.name.compareTo(s.name);
return num;
}
public String getName()
{
return name;
}
public int getAge()
{
return age;
}
}

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