import java.util.HashMap;

import java.util.Set;

import java.util.Map.Entry;

public class MapDemo {

    public static void main(String[] args) {

        //定义javas班的集合

        HashMap<String, String> javas=new HashMap<String,String>();

        //定义Hdoop班集合

        HashMap<String, String> Hdoop=new HashMap<String,String>();

        //向班级存储学生

        javas.put("001", "熊大");

        javas.put("002", "熊二");

        Hdoop.put("001", "小猪猪");

        Hdoop.put("002", "小菲菲");

        //定义AAA容器，键是班级的名字，值是两个班级的容器

        HashMap<String, HashMap<String, String>>  AAA=new HashMap<String, HashMap<String, String>>();

        AAA.put("javas班", javas);

        AAA.put("Hdoop班", Hdoop);

        entrySet1(AAA);

    }

    private static void entrySet1(HashMap<String, HashMap<String, String>> AAA) {

        //调用集合AAA的方法，entrySet将AAA集合的键封装到Set集合中。

        Set<Entry<String, HashMap<String, String>>> aaa=AAA.entrySet();

    //增强for循环遍历set集合

        for(Entry<String, HashMap<String, String>> p:aaa){

                    //System.out.println(p);

            //getkey获得AAA的键，getValue获得值

            String classNameKey=p.getKey();

            HashMap<String, String> classMap =p.getValue();

            System.out.println(classNameKey);

            //System.out.println(classMap);

            //将classMap装进Set集合

            Set<Entry<String, String>> s=classMap.entrySet();

            for (Entry<String, String> q:s) {

                //getKey获得班级的键，getValue获得值

                String numKey=q.getKey();

                String nameValue=q.getValue();

                System.out.println(numKey+":    "+nameValue);

            }

        }

    }

}

import java.util.Iterator;

import java.util.Map.Entry;

import java.util.HashMap;

import java.util.Set;

//Map嵌套存储Map

public class MaoMapDemo {

    public static void main(String[] args) {

        //定义javas班的集合

        HashMap<String, String> javas=new HashMap<String,String>();

        //定义Hdoop班集合

        HashMap<String, String> Hdoop=new HashMap<String,String>();

        //向班级存储学生

        javas.put("001", "熊大");

        javas.put("002", "熊二");

        Hdoop.put("001", "小猪猪");

        Hdoop.put("002", "小菲菲");

        //定义AAA容器，键是班级的名字，值是两个班级的容器

        HashMap<String, HashMap<String, String>>  AAA=new HashMap<String, HashMap<String, String>>();

        AAA.put("javas班", javas);

        AAA.put("Hdoop班", Hdoop);

        entrySet1(AAA);

    }

    private static void entrySet1(HashMap<String, HashMap<String, String>> AAA) {

        //调用集合AAA的方法，entrySet将AAA集合的键封装到Set集合中。

        Set<Entry<String, HashMap<String, String>>> classNameSet=AAA.entrySet();

/*迭代Set集合*/

        //集合绑定迭代器

        Iterator<Entry<String, HashMap<String, String>>> it=classNameSet.iterator();

        while (it.hasNext()) {

            //遍历集合

            Entry<String, HashMap<String, String>>  next= it.next();

            //System.out.println(next);

            //getkey获得键，getValue获得值

            String classNameKey=next.getKey();

            HashMap<String, String> classMap = next.getValue();

            //AAA容器的键，班级名字classNameKey

            System.out.println(classNameKey);

            //AAA容器的值，班级所有元素classMap

            //System.out.println(classMap);

            //entrySet将classMap集合的键封装到Set集合中。

            Set<Entry<String, String>> studentSet=classMap.entrySet();

            //迭代，集合绑定迭代器

            Iterator<Entry<String, String>> studentIt=studentSet.iterator();

            while (studentIt.hasNext()) {

                //遍历集合

                Entry<String, String> studentEntry = studentIt.next();

                //getkey获得键，getValue获得值

                String numKey=studentEntry.getKey();

                String nameValue=studentEntry.getValue();

                System.out.println(numKey+":    "+nameValue);

            }

        }

    }

}