如何用构造函数初始化内部类的新字段？

Question

如果我有这个类并且我想初始化一个类型为

Element

的新字段， 我该怎么做？

public class MyLinkedList{
    
   protected Element head, tail;
   
   public final class Element{
      Object data;
      int priority; 
      Element next;
      
      Element(Object obj, int priorit, Element element){
       data = obj;
       priority = priorit;
       next = element;
      }
   }
}

当我尝试这样做时，它给了我一个错误。

public class PriorityTest{
    public static void main(String[]args){  
        MyLinkedList.Element e1 = new MyLinkedList.Element("any", 4, null); 
    }
}

Answer 1

使内部类静态化

public class MyLinkedList{

   protected Element head, tail;

   public static final class Element{
      Object data;
      int priority;
      Element next;

      Element(Object obj, int priorit, Element element){
       data = obj;
       priority = priorit;
       next = element;
      }
   }

  public static void main(String[]args){
      MyLinkedList.Element e1 = new MyLinkedList.Element("any", 4, null);
  }
}

Answer 2

试试这个

MyLinkedList.Element e1 = new MyLinkedList().new Element("any", 4, null);

你的内部类不是

static

所以你需要先创建一个外部类的对象。