HashMap的嵌套应用

public class HashMapDemo3 {
public static void main(String[] args) {
//
HashMap<String,HashMap<String,ArrayList<Student>>> czbkMap=new HashMap<String,HashMap<String,ArrayList<Student>>>();
//北京校区
HashMap<String,ArrayList<Student>> bjCzbkMap=new HashMap<String,ArrayList<Student>>();
ArrayList<Student> array1=new ArrayList<Student>();
Student bs1=new Student("jc张三",20);
Student bs2=new Student("jc李四",21);
array1.add(bs1);
array1.add(bs2);
ArrayList<Student> array2=new ArrayList<Student>();
Student bs3=new Student("jy张三",20);
Student bs4=new Student("jy李四",21);
array2.add(bs3);
array2.add(bs4);

bjCzbkMap.put("基础班", array1);
bjCzbkMap.put("就业班", array2);

czbkMap.put("北京校区", bjCzbkMap);

// System.out.println(czbkMap);
//上海校区
HashMap<String,ArrayList<Student>> shCzbkMap=new HashMap<String,ArrayList<Student>>();
ArrayList<Student> array3=new ArrayList<Student>();
Student ss1=new Student("jc张三",20);
Student ss2=new Student("jc李四",21);
array3.add(ss1);
array3.add(ss2);
ArrayList<Student> array4=new ArrayList<Student>();
Student ss3=new Student("jy张三",20);
Student ss4=new Student("jy李四",21);
array4.add(ss3);
array4.add(ss4);

shCzbkMap.put("基础班", array3);
shCzbkMap.put("就业班", array4);

czbkMap.put("上海校区", shCzbkMap);


//武汉校区
HashMap<String,ArrayList<Student>> whCzbkMap=new HashMap<String,ArrayList<Student>>();
ArrayList<Student> array5=new ArrayList<Student>();
Student ws1=new Student("jc张三",20);
Student ws2=new Student("jc李四",21);
array5.add(ws1);
array5.add(ws2);
ArrayList<Student> array6=new ArrayList<Student>();
Student ws3=new Student("jy张三",20);
Student ws4=new Student("jy李四",21);
array6.add(ws3);
array6.add(ws4);

whCzbkMap.put("基础班", array1);
whCzbkMap.put("就业班", array2);

czbkMap.put("武汉校区", whCzbkMap);


//广州校区
HashMap<String,ArrayList<Student>> gzCzbkMap=new HashMap<String,ArrayList<Student>>();
ArrayList<Student> array7=new ArrayList<Student>();
Student gs1=new Student("jc张三",20);
Student gs2=new Student("jc李四",21);
array7.add(gs1);
array7.add(gs2);
ArrayList<Student> array8=new ArrayList<Student>();
Student gs3=new Student("jy张三",20);
Student gs4=new Student("jy李四",21);
array8.add(gs3);
array8.add(gs4);

gzCzbkMap.put("基础班", array7);
gzCzbkMap.put("就业班", array8);

czbkMap.put("广州校区", gzCzbkMap);

//遍历集合
Set<String> czbkMapSet=czbkMap.keySet();

for(String strKey:czbkMapSet ){
HashMap<String,ArrayList<Student>> czbkMapSetValue=czbkMap.get(strKey);
System.out.println(strKey);
Set<String> czbkMapValueSet=czbkMapSetValue.keySet();
for(String studentKey:czbkMapValueSet){
ArrayList<Student> arr=czbkMapSetValue.get(studentKey);
System.out.println(" "+studentKey);
for(Student s:arr){
System.out.println(" "+s.getName()+"--------"+s.getAge());
}

}
}
}
}