//两种方法

/**

*1，利用KeySet方法遍历

*/

public void test testKeySet(){

    Set<String>KeySet = students.keySet();

    for(String stuId:KeySet){

        Student stu = students.get(stuId);

        if(stu!=null){

            System.out.println("学生："+stu.name);

        }

    }

}

/**

*2，利用EntrySet方法遍历

*/

public void testEntrySet(){

    Set<Entry<String,Student>>entrySet = students.entrySet();

    for(Set<Entry<String,Student>>entry:entrySet){

        System.out.println("取得键："+entry.getKey());

        System.out.println("对应的值为："+entry.getValue().name);

}