出现No enclosing instance of type is accessible解决方法

出现No enclosing instance of type is accessible解决方法

No enclosing instance of type hello is accessible. Must qualify the allocation with an enclosing instance of type hello (e.g. x.new A() where x is an instance of hello).

检查一下自己一个文件多个类的写法是否正确
一个文件只能有一个类是public，
其他类调用一个文件的非public类时候可以用“包名.类名”

public class Test{
        public static void main(String args[]){
               new B();
       }
}
class A {
        public A(){
              System. out.println("I am A" );
       }

}

class B  extends  A{
        public B(){
              System. out.println("I am B" );
       }

}