Java基础视频教程第16天-09-集合(Map扩展)

/*
map扩展知识。

map集合被使用是因为具备映射关系。

"yureban"   Student("01" "zhangsan");

"yureban" Student("02" "lisi");

"jiuyeban" "01" "wangwu";
"jiuyeban" "02" "zhaoliu";

一个学校有多个教室。每一个教室都有名称。


*/
import java.util.*;

class Student
{
    private String id;
    private String name;
    Student(String id,String name)
    {
        this.id = id;
        this.name = name;
    }
    public String toString()
    {
        return id+":::"+name;
    }
}
class MapDemo3
{

    public static void demo()
    {
        HashMap<String,List<Student>> czbk = new HashMap<String,List<Student>>();

        List<Student> reyu = new ArrayList<Student>();
        List<Student> jiuye = new ArrayList<Student>();

        czbk.put("yureban",reyu);
        czbk.put("jiuyeban",jiuye);

        reyu.add(new Student("01","zhagnsa"));
        reyu.add(new Student("04","wangwu"));
        jiuye.add(new Student("01","zhouqi"));
        jiuye.add(new Student("02","zhaoli"));


        Iterator<String> it = czbk.keySet().iterator();

        while(it.hasNext())
        {
            String roomName = it.next();
            List<Student> room = czbk.get(roomName);

            System.out.println(roomName);
            getInfos(room);
        }




    }
    public static void getInfos(List<Student> list)
    {
        Iterator<Student> it = list.iterator();
        while(it.hasNext())
        {
            Student s = it.next();
            System.out.println(s);
        }
    }




    public static void main(String[] args)
    {
         demo();

        /*
        HashMap> czbk = new HashMap>();

        HashMap yure = new HashMap();

        HashMap jiuye = new HashMap();

        czbk.put("yureban",yure);
        czbk.put("jiuyeban",jiuye);


        yure.put("01","zhagnsan");
        yure.put("02","lisi");

        jiuye.put("01","zhaoliu");
        jiuye.put("02","wangwu");



        //遍历czbk集合。获取所有的教室。
        Iterator it = czbk.keySet().iterator();

        while(it.hasNext())
        {
            String roomName = it.next();
            HashMap room = czbk.get(roomName);

            System.out.println(roomName);
            getStudentInfo(room);
        }


//        getStudentInfo(jiuye);
//        getStudentInfo(yure);
*/

    }
    public static void getStudentInfo(HashMap<String,String> roomMap)
    {
        Iterator<String> it = roomMap.keySet().iterator();

        while(it.hasNext())
        {
            String id = it.next();
            String name = roomMap.get(id);
            System.out.println(id+":"+name);
        }
    }
}