函数不会引用带有我正在创建的节点的链表

Question

当我在main中调用readFile方法时，我得到了一个错误，即我的readFile方法没有定义。这怎么可能？

import java.util.Scanner;
import java.util.List;

public class Node {
    int value; 
    Node next; 

    /** 
     * Constructor 
     * @param value The element to store in this node, an integer from file
     */
    public Node(int value) {
        this.value = value;
        next = null; 
    }

    public static Node first;
    public static Node last; 

    public void linkedList() {
        first = null; 
        last = null;
    }

    /** 
     * function sorts integers 
     * @param inputFile file of integers from user
     * @return linked list of sorted integers 
     */
    public static Node readFile(Scanner inputFile) {

        while (inputFile.hasNext()) {
            int data = inputFile.nextInt(); 
            if (first == null) {
                first = new Node(data);
                last = first; 
            }
            if (data < first.value) {
                first.next = first; 
                first = new Node(data);
            }
            if (data > first.value) {
                last.next = new Node(data); 
                last = last.next; 
            }
        }
        return first; 
    }

    /**
     * function prints linked list
     */
    public void print() { 
        Node ref = first; 

        while (ref != null) {
            System.out.println(ref.value + " ");
            ref = ref.next;
        }
    }
}

这是我的主要驱动程序：

    import java.util.Scanner;
    import java.util.List;
    import java.io.*; 

    public class listTesting {
    private static final String FILENAME = "numbers.txt"; 

    public static void main(String[] args) throws IOException {

        Scanner keyboard = new Scanner(System.in); 

        System.out.print("Opening " + FILENAME);
        File file = new File(FILENAME);
        Scanner inputfile = new Scanner(file);

        linkedList list = new linkedList(); 

        // error here stating this method is undefined ??
        list = readFile(inputfile);

        System.out.println("\nThe sorted linked list: ");
        list.print(); 
    }
}

Answer 1

在类中，listTesting不是任何与节点类的链接。对于这一行

list = readFile(inputfile);

编译器试图在listTesting类中查找静态方法。

下一个我不清楚的是：

linkedList list = new linkedList(); 

// error here stating this method is undefined ??
list = readFile(inputfile);