无法调用匿名类方法

我正在尝试调用一个方法，setPostal(String post)我是从一个匿名类创建的，但由于某种原因，编译器在缅因州甚至无法识别它。这是有什么原因吗？我的代码的一部分（地址是Student的内部类）：

Student

public class Student implements Gradeable, Cloneable {
    String name;
    int id;
    Address address;

    public Student() {
        name = "unknown";
        address = new Address();
    }

    public Student(String name, int id, Integer... option) {
        this.name = name;
        this.id = id;
        if (option.length > 0) {
            if (option[0] > 0) {
                address = new Address() {
                    String postal;

                    public void setPostal(String post) {
                        postal = post;
                    }

                    @Override
                    public String toString() {
                        return "Street: " + street + " | number: " + number
                                + " | town: " + town + " | province: " + province
                                + " | Postal Code: " + postal;
                    }
                };
            }
        } else {
            address = new Address();
        }
    }

    Address getAddress() {
        return address;
    }

    void setAddress(Address address) {
        this.address = address;
    }

    public static void main(String[] args) throws CloneNotSupportedException, InterruptedException {
        Student test = new Student("ryan", 41254, 1);
        test.getAddress().setPostal("L1G 6h9") // Compiler: Cannot resolve symbol 'setPostal'
    }
}

Address

public class Address implements Cloneable {
    String street;
    int number;
    String town;
    String province;
    String zip;

    public Address() {

    }

    public Address(String street, int number, String town,
                   String province, String zip) {
        this.street = street;
        this.number = number;
        this.town = town;
        this.province = province;
        this.zip = zip;
    }

    String getStreet() {
        return street;
    }

    int getNumber() {
        return number;
    }

    String getTown() {
        return town;
    }

    String getProvince() {
        return province;
    }

    String getZip() {
        return zip;
    }

    @Override
    public String toString() {
        return "Street: " + street + " | number: " + number
                + " | town: " + town + " | province: " + province
                + " | ZIP: " + zip;
    }

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof Address)
            if (((Address) obj).getStreet().equals(street)
                    && ((Address) obj).getNumber() == number
                    && ((Address) obj).getTown().equals(town)
                    && ((Address) obj).getProvince().equals(province)
                    && ((Address) obj).getZip().equals(zip)){
                System.out.println("Address equal");
                return true;
            }
        System.out.println("Address not equal");
        return false;
    }

    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }
}

想必，无论怎样Address是，它没有setPostal(String)方法。

实例方法在编译时根据调用它们的值的类型进行解析。

你正在调用它

test3.getAddress().setPostal("L1G 6h9") //Compiler: Cannot resolve symbol 'setPostal'

在类型表达式上Address，它没有这样的方法，不管子类型（匿名子类）有这样的方法。

调用仅在匿名类中声明的方法的唯一方法（减去反射）是对匿名类实例创建表达式返回的值调用该方法。

new Address() {
    String postal;
    public void setPostal(String post) {
        postal = post;
    }

    @Override
    public String toString() {
        return "Street: " + street + " | number: " + number
                        + " | town: " + town + " | province: " + province
                        + " | Postal Code: " + postal;
        }
    }
}.setPostal("whatever");