Linked List 2:Merge two sorted LL

public class Solution {
  
    public static LinkedListNode<Integer> mergeTwoList(LinkedListNode<Integer> head1, LinkedListNode<Integer> head2) {
        if(head1==null)
            return head2;
        if(head2==null)
            return head1;
        LinkedListNode<Integer> t1=head1,t2=head2,tail=null,head=null;
        if(t1.data<=t2.data)
        {
            head=t1;
            tail=t1;
            t1=t1.next;
        }
        else
        {
            head=t2;
            tail=t2;
            t2=t2.next;
        }
        while(t1!=null &&t2!=null)
        {
            if(t1.data<=t2.data)
            {
                tail.next=t1;
                tail=t1;
                t1=t1.next;
            }
            else
            {
                tail.next=t2;
                tail=tail.next;
                t2=t2.next;
            }
        }
        if(t1==null)
            tail.next=t2;
        if(t2==null)
            tail.next=t1;
        return head;

    }
}