求指导！！！ - 黑马程序员技术交流社区

<div class="blockcode"><blockquote>import java.util.*;
class Student implements Comparable<Student>{
private String name;
private int age;
Student(String name, int age){
this.name = name;
this.age = age;
}
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 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 String getName(){
return name;
}
public int getAge(){
return age;
}
public String toString(){
return name+":"+age;
}
@Override
public int compareTo(Student o) {
// TODO Auto-generated method stub
return 0;
}
}
public class MapTest{
public static void main(String[] args){
HashMap<Student,String> hm = new HashMap<Student,String>();
hm.put(new Student("lisi",21),"beijing");
hm.put(new Student("lisi",21),"tianjin");
hm.put(new Student("lisi2",22),"shanghai");
hm.put(new Student("lisi3",23),"nanjing");
hm.put(new Student("lisi4",24),"shenyang");
//第一种取出方式 keySet
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(stu+".."+addr);
}
//第二种取出方式 entrySet
Set<Map.Entry<Student,String>> entrySet = hm.entrySet();
Iterator<Map.Entry<Student,String>> iter = entrySet.iterator();
while(it.hasNext()){
Map.Entry<Student,String> me = iter.next();
Student stu = me.getKey();
String addr = me.getValue();
System.out.println(stu+"....."+addr);
}
}
}

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