Find Middle element of Linked list in java

public ListNode findMiddle(ListNode head){
ListNode ptr1x,ptr2x;
ptr1x = ptr2x = head;
int i = 0;

while(ptr1x.getNext()!=null){
if(i == 0){
ptr1x = ptr1x.getNext();
i = 1;
}
else{
ptr1x = ptr1x.getNext();
ptr2x = ptr2x.getNext();
i = 0;
}
}

return ptr2x;
}