被private修飾的內部類只能在它所屬的外部類中訪問
class Outer{

private int num = 10;

public int getNum(){
return num;
}

public void setNum(int num){
this.num = num;
}

//內部類的定義
private class Inner{

    public void show(){
        System.out.println("我是內部類");
        System.out.println("num:"+num);
    }
}

/**
 * 對內部類的封裝，給其他的外部類提供介面來訪問Inner內的方法
 */
public void method(){
    Inner inner = new Inner();
    inner.show();
}
 

}

class OutDemo1{

public static void main(String [] args){
    //被private修飾的內部類只能在它所屬的外部類中訪問
    //Outer.Inner inner = new Outer().new Inner();

    Outer outer = new Outer();
    outer.setNum(12);
    System.out.println(outer.getNum());

    outer.method();
} 

}