为什么输入了数据显示不了，应该如何解决

 
package DateStructuresHomework;
 
import homework.F;
 
public class SingleLinkedList {
    private Node head=new Node("");
    public void insert(Node Node)
    {
        Node temp=head;
        while (true)
        {
            if (temp.next==null)
                break;
            temp=temp.next;
 
        }
        temp.next=Node;
        display();
 
 
    }
    public void delete(int no)
    {
        Node temp=head;
 
        for (int i = 0; i next;
        }
        temp.next=temp.next.next;
        display();
    }
    public void find(Object x)
    {
        Node temp=head;
        int n=0;
        while (temp.next==null)
        {
            if (temp.val==x)
            {
 
                break;
            }
            n++;
        }
        System.out.println(n);
    }
    public void display()
    {
        Node temp=head;
        while (temp.next==null)
            System.out.print(temp.val+" ");
    }
 
 
 
 
 
}
 
class Node{
    public Object val;
    public Node next;
 
 
    public Object getVal() {
        return val;
    }
 
    public void setVal(Object val) {
        this.val = val;
    }
 
    public Node getNext() {
        return next;
    }
 
    public void setNext(Node next) {
        this.next = next;
    }
 
    public Node(Object val) {
        this.val = val;
    }
}
 
 
 
 
 
class Test2
{
    public static void main(String[] args) {
        Node node1=new Node(1);
        Node node2=new Node(2);
        SingleLinkedList singleLinkedList=new SingleLinkedList();
        singleLinkedList.insert(node1);
        singleLinkedList.insert(node2);
        singleLinkedList.display();
    }
}

你输入的代码呢，你只调用了system.out，system.in在哪调用过？