集合框架四（Map接口）

package us.google.www;

public class Person implements Comparable {

private String name;

private int age;

public Person() {

super();

// TODO Auto-generated constructor stub

}

public Person(String name, int age) {

super();

this.name = name;

this.age = age;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}

@Override

public int compareTo(Person o) {

if(o==null)

{

throw new NullPointerException();

}

if(this.age>o.age)

{

return 1;

}

if(this.age

使用HashMap模拟通讯录，实现对通讯录的（CRUD）联系人：Contact，通讯录：Contacts

Contact类

package us.google.homework;

/**

* 联系人

* @author chongrubujing

*

*/

public class Contact {

private String name;

private String phoneNumber;

public Contact() {

super();

// TODO Auto-generated constructor stub

}

public Contact(String name, String phoneNumber) {

super();

this.name = name;

this.phoneNumber = phoneNumber;

}

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public String getPhoneNumber() {

return phoneNumber;

}

public void setPhoneNumber(String phoneNumber) {

this.phoneNumber = phoneNumber;

}

@Override

public String toString() {

return “Contact [name=” + name + “, phoneNumber=” + phoneNumber + “]”;

}

}

Contacts类

package us.google.homework;

import java.util.HashMap;

import java.util.Map;

/**

* 通讯录

* @author chongrubujing

*

*/

public class Contacts {

private Map

HomeWork类

package us.google.homework;

import java.util.Iterator;

import java.util.Map;

import java.util.Set;

public class HomeWork {

public static void main(String[] args) {
Contacts cs = new Contacts();
System.out.println("-------添加联系人-----------");
cs.add(new Contact("小白","18203609683"));
cs.add(new Contact("小黑","18203609683"));
cs.add(new Contact("小黄","18203609683"));
cs.add(new Contact("小三","18203609683"));
cs.add(new Contact("小二","18203609683"));
//获取所有的联系人，并把所有的联系人转换成Map集合
Map<Integer,Contact> maps = cs.getContacts();
Set<Integer> keyset = maps.keySet();
Iterator<Integer> iter = keyset.iterator();
while ((iter.hasNext())) {
Integer key = iter.next();
System.out.println("id:"+key+"---"+maps.get(key));
}
System.out.println("--------修改联系人-----------");
cs.update(2, new Contact("孟子","123456789"));
Map<Integer, Contact> maps1 = cs.getContacts();
Set<Integer> keyset1 = maps1.keySet();
Iterator<Integer> iter1 = keyset1.iterator();
while ((iter1.hasNext())) {
Integer key1 = iter1.next();
System.out.println("id:"+key1+"---"+maps1.get(key1));
}
System.out.println("---------删除联系人------------");
cs.delete(3);
Map<Integer, Contact> maps3 = cs.getContacts();
Set<Integer> keyset3 = maps3.keySet();
Iterator<Integer> iters3 = keyset3.iterator();
while(iters3.hasNext()){
Integer key = iters3.next();
System.out.println("id:"+key+"--"+maps3.get(key));
}
System.out.println("--------查找联系人-------------");
Contact contact = cs.find(1);
System.out.println(contact);
}

}