Any of those help It seems you try to pass the data whit: document.location.href="/MachineProblemWebApp/UpdateProductServlet"; and it is not possible, because this line just redirect to "UpdateProductServlet" without sending the data.
Passing Data from JSP to Servlet
By : Andrew Kim
Date : March 29 2020, 07:55 AM
it should still fix some issue Why String name = "id"; String value = request.getParameter(name); ? I can't seem to find any input in your JSP that's name = "id" ... In the servlet, you should have this (for example), this :