Java 核心技术（第八版）卷1：基础知识：例13-5P582MapTest

import java.util.*;
//本程序演示 map 的使用，它的key 是 String，值是Employee类型
public class MapTset {
    public static void main(String[]args)
    {
        Map staff=new HashMap();
        staff.put("144-25-5464",new Employee("Amy Lee"));
        staff.put("567-24-2546",new Employee("Harry Hacker"));
        staff.put("157-62-7935",new Employee("Gary Cooper"));
        staff.put("456-62-5527",new Employee("Francersca Cruz"));

        // print all entries
        System.out.println(staff);
        //remove an entry
        staff.remove("567-24-2546");
        System.out.println("After remove Key:567-24-2546 :");
        System.out.println(staff);
        //replace an entry
        staff.put("456-62-5527",new Employee("Francesca Miller"));
        System.out.println("After replace Key:456-62-5527 :");
        System.out.println(staff);
        //iterate through all entries
        System.out.println("Let have a iteration:");
        for(Map.Entry entry:staff.entrySet())
        {
            String key=entry.getKey();
            Employee value=entry.getValue();
            System.out.println("key="+key+",value="+value);
        }




    }
}
//mini employee class for test purpose
class Employee
{
    public Employee(String n)
    {
        name=n;
        salary=0;
    }
    public String toString()
    {
        return "[name="+name+",salary="+salary+"]";
    }

    private String name;
    private double salary;
}

运行结果：

{157-62-7935=[name=Gary Cooper,salary=0.0], 144-25-5464=[name=Amy Lee,salary=0.0], 456-62-5527=[name=Francersca Cruz,salary=0.0], 567-24-2546=[name=Harry Hacker,salary=0.0]}
After remove Key:567-24-2546 :
{157-62-7935=[name=Gary Cooper,salary=0.0], 144-25-5464=[name=Amy Lee,salary=0.0], 456-62-5527=[name=Francersca Cruz,salary=0.0]}
After replace Key:456-62-5527 :
{157-62-7935=[name=Gary Cooper,salary=0.0], 144-25-5464=[name=Amy Lee,salary=0.0], 456-62-5527=[name=Francesca Miller,salary=0.0]}
Let have a iteration:
key=157-62-7935,value=[name=Gary Cooper,salary=0.0]
key=144-25-5464,value=[name=Amy Lee,salary=0.0]
key=456-62-5527,value=[name=Francesca Miller,salary=0.0]

进程已结束,退出代码0