- 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 67;
- }
- 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;
- }
- }
- class MapTest
- {
- public static void main(String[] args)
- {
- HashMap<Student,String> hm = new HashMap<Student,String>();
- hm.put(new Student("lisi1",21),"beijing");
- hm.put(new Student("lhsi1",21),"beijing");
- hm.put(new Student("lisi2",22),"tianjin");
- hm.put(new Student("liti3",23),"nanjing");
- hm.put(new Student("lisi3",23),"nanjing");
- hm.put(new Student("lisi4",24),"dongjing");
- //第一种取出方式:
- 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:
- Set<Map.Entry<Student,String>> entrySet = hm.entrySet();
- Iterator<Map.Entry<Student,String>> iter = entrySet.iterator();
- while(iter.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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