Singly Linked List Deletion in Java

import java.lang.*;

// Node Class
class Node {
    int data;
    Node next;

    Node(int x) // parameterized constructor
    {
        data = x;
        next = null;
    }
}

class Main
{
    static Node insert(Node head, int data)
    {
        // Creating newNode memory & assigning data value
        Node newNode = new Node(data);

        // assigning this newNode's next as current head node
        newNode.next = head;
        // re-assigning head to this newNode
        head = newNode;

        return head;
    }

    static Node deletepos(Node head, int pos)
    {
        Node temp = head;
        Node previous = null;

        int size = calcSize(head);

        if(pos < 1 || pos > size){
            System.out.println("Enter valid position");
            return head;
        }

        //if the head node itself needs to be deleted
        if(pos == 1){
            //changing head to next in the list
            head = temp.next;
            System.out.println("Deleted Item: "+ temp.data);
            return head;
        }

        //run until we find the value to be deleted in the list
        while (--pos > 0) {
            // store previous link node as we need to change its next val
            previous = temp;
            temp = temp.next;
        }

        // (pos-1)th node's next assigned to (pos+1)nth node
        previous.next = temp.next;
        System.out.println("Deleted Item: "+ temp.data);

        return head;
    }

    static void display(Node node) {

        //as linked list will end when Node is Null
        while (node != null) {
            System.out.print(node.data + " ");
            node = node.next;
        }
        System.out.println();
    }

    public static int calcSize(Node node){
        int size = 0;
        // traverse to the last node each time incrementing the size
        while(node!=null){
            node = node.next;
            size++;
        }
        return size;
    }

    public static void main(String args[])
    {
        Node head = null;
        head = insert(head,60);
        head = insert(head,50);
        head = insert(head,40);
        head = insert(head,30);
        head = insert(head,20);
        head = insert(head,10);

        display(head);

        head = deletepos(head,1);
        display(head);

        head = deletepos(head,3);
        display(head);

        head = deletepos(head,4);
        display(head);

        head = deletepos(head,-2); // not valid as pos negative
        head = deletepos(head,10); // not valid as breaches size of Linked List1);
        display(head);

    }
}

Output

10 20 30 40 50 60 
Deleted Item: 10
20 30 40 50 60 
Deleted Item: 40
20 30 50 60 
Deleted Item: 60
20 30 50 
Enter valid position
Enter valid position
20 30 50