不能访问Person类型的封闭实例

Question

我想知道是否有人能告诉我为什么我在第175行得到一个错误

Student george= new Student("George Flintstone", 21, "Politics", 3.1);

表示没有可访问的person类型的封闭实例。我看过其他类似的问题，但我不是很熟悉java，所以我没有真正找到一个答案，至少一个我理解得足够好。这是我java入门课的作业。我并没有在FAQ中看到任何内容说我不能在作业上寻求帮助，但我承认我没有非常仔细地阅读它，所以如果我违反了某些规则或其他规则，请告诉我。

还有，很抱歉发布了这么多代码，我不确定哪些部分可能是重要的。

Public class Person {
    String name;
    int age;
    public Person(String n, int a)
    {
        name = n;
        age = a;
    }
    public Person()
    {
        name = "Bob";
        age = 24; 
    }
    public void set_Person(String n)
    {
        name = n;
    }
    public void set_Person(int a)
    {
        age = a;
    }
    public void set_Person(String n, int a)
    {
        name = n;
        age = a;
    }
    public String get_Name()
    {
        return name;
    }
    public int get_Age()
    {
        return age;
    }
    public boolean equals(Object ob)
    {
        Person p = (Person)ob;
        if(ob == null)
            return false;
        if(name.equals(p.name) && age == p.age)
            return true;
        else
            return false;
    }
    public String toString()
    {
        String temp = name + " is " + age + " years old ";
        return temp;
    }
class Student {
    String major;
    double gpa;
    Person p = new Person();
    Student(String n, int a, String m, double g )
    {
        p.set_Person(n,a);
        major = m;
        gpa = g;
    }
    Student()
    {
        p.set_Person("Ben", 10);
        major = "compsci";
        gpa = 3.5;
    }
    public void set_Student(String n, int a, String m, double g)
    {
        p.set_Person(n,a);
        major = m;
        gpa = g;
    }
    public void set_Student(String n)
    {
        p.set_Person(n);
    }
    public void set_Student(int a)
    {
        p.set_Person(a);
    }
    public String getStudentName()
    {
        String temp = p.get_Name();
        return temp;
    }
    public int getStudentAge()
    {
        return p.get_Age();
    }

}
class Family {

    Person [] per_array;
    int person_count = 0;
    Person temp = new Person();
    Family(int members)
    {
        Person[] per_array = new Person[members];
    }
    public void addPerson(Person p)
    {
        boolean check = false;
        for(int count = 0; count < per_array.length; count++){
            if(per_array[count].equals(p))
            {
                System.out.println("That person is already a member of this family");
                check = true;
            }
        }
        if(check = false){
            per_array[person_count] = p;
            person_count++;
        }
    }
    public void addPerson(Student s)
    {
        temp.set_Person(s.getStudentName(), s.getStudentAge());
        boolean check = false;
        for(int count = 0; count < per_array.length; count++){
            if(per_array[count].equals(temp))
            {
                System.out.println("That person is already a member of this family");
                check = true;
            }
        }
        if(check = false){
            per_array[person_count] = temp;
            person_count++;
        }
    }
    public void printOutFamily()
    {
        for(int count = 0; count < per_array.length; count++)
        {
            per_array[count].toString();
        }
    }
}
    public static void main(String[] args) {
        Person fred= new Person("Fred Flintstone", 50);
        System.out.println("created " + fred);
        Person wilma = new Person("Wilma Flintstone", 48);
        Student george= new Student("George Flintstone", 21, "Politics", 3.1);
        System.out.println("created " + george);
        Student sue= new Student("Sue Flintstone", 24, "Nursing", 3.3);
        Student anotherGeorge= new Student("George Flintstone", 21, "Math", 3.4);
        Person yetAnotherGeorge= new Person("George Flintstone", 21);
        Family f = new Family(10);
        f.addPerson(fred);
        f.addPerson(wilma);
        f.addPerson(george);
        f.addPerson(sue);
        f.addPerson(anotherGeorge);
        f.addPerson(yetAnotherGeorge);
        anotherGeorge.set_Student("Georgie Flintstone");
        f.addPerson(anotherGeorge);
        f.printOutFamily();
    }
}

Answer 1

Student是一个内部类，它与Person的特定实例相关联，这意味着调用

是无效的。

new Student("George Flintstone", 21, "Math", 3.4);*

使内部类static将允许它工作。静态内部类，也就是嵌套类，不需要外部类的实例，这里是Person。