package demo;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Set;

import java.util.Map.Entry;;

public class Demo {

	public static void main(String[] args) {

		//定义一班的集合

		HashMap<String, String> class1 = new HashMap<String, String>();

		//定义二班的集合

		HashMap<String, String> class2 = new HashMap<String, String>();

		//向班级存储学生

		class1.put("001", "张三");

		class1.put("002", "李四");

		class2.put("001", "王五");

		class2.put("002", "马六");

		 //定义grade容器  键是班级的名字  值是两个班级的容器

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

		grade.put("class1", class1);

		grade.put("class2",class2);

		entrySet1(grade);

	}

	public static void entrySet1(HashMap<String, HashMap<String, String>> grade) {

		//entrySet():返回此映射中包含的映射关系的 Set 视图。

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

		//迭代Set集合

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

		while(it.hasNext()) {

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

			//得到班级的名字

			String classNameKey = next.getKey();

			System.out.println(classNameKey);

			//得到具体每个班的map集合

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

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

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

			while(studentIt.hasNext()) {

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

				//得到每个班级的同学的键

				String numKey = studentEntry.getKey();

				//得到每个班级同学键所对应的的值

				String numValue = studentEntry.getValue();

				System.out.println(numKey+"\t"+numValue);

			}

		}

	}

}