How to find nth element from the end of a singly linked list

package linkedlist.singly;

//How would you find the nth to last element in a linked list?
//Say find 3rd last element of linklist.
//If we keep a gap of 3 Nodes between p1 and p2 and then start incrementing both p1 and p2 one by one until p2 which is 3 element ahead of p1 is null. now when p2 is null, then p1 will be at 3rd last position.
//this says, keep p1 and p2 at node 1 initially. then move p2 to n(n=3 in our case) location ahead. if p2 becomes null in between moving it to 3 positions ahead 
//then we will not able to find nth last element in linklist as it doen't contain that much element.
//otherwise, once p2 advanced to 3 locations ahead, now start iterating one by one until p2 reaches null, when p2 reaches null, p1 will be at 3rd last position.
public class GetNthLastElementFromList {

 Node startNode;
 public static void main(String[] args) {
  new GetNthLastElementFromList();
 }
 
 public GetNthLastElementFromList() {
  
  addNode(new Node(10));
  addNode(new Node(20));
  addNode(new Node(30));
  addNode(new Node(40));
  addNode(new Node(50));
  addNode(new Node(60));
  addNode(new Node(70));

  printLinkList();
  System.out.println(getNthElementSolution1(7));
  //System.out.println(getNthElementSolution2(startNode, 1));  
 }

 // Solution 1
 private int getNthElementSolution1(int nodeFromLast) {

  if(nodeFromLast<=0 || startNode==null){
   return -1;
  }

  Node temp1= startNode, temp2 = startNode;

  for (int i=0; i < nodeFromLast; i++) {
   if(temp2==null){
    return -1;
   }
   temp2 = temp2.getNext();
  }

  while(temp2!=null){
   temp2= temp2.getNext();
   temp1=temp1.getNext();
  }

  return temp1.getData();  
 }

 // Solution 2 : it uses single for loop.
 private static int getNthElementSolution2(Node startNode, int nth) {
  Node temp1=startNode, temp2 = startNode;
  int count=0;
  for(;temp1!=null;){
   count++;
   if(nth-count<0){
    temp2 = temp2.getNext();
   }
   temp1 = temp1.getNext();
  }
  
  if(count>=nth){
   return temp2.getData();
  }
  return -1;
 }

 private void printLinkList() {
  Node tempNode = startNode;
  while(tempNode!=null){
   System.out.print(tempNode.getData() + " ");
   tempNode = tempNode.getNext();
  }
  System.out.println("\n============================================");
 }

 private void addNode(Node node) {
  if(startNode!=null){
   Node tempNode = startNode;
   while(tempNode.getNext()!=null){
    tempNode = tempNode.getNext();
   }
   tempNode.setNext(node);
  }else{
   this.startNode = node;
  }
 }
}