Java and java script

Question

i have a web application. written in java and js. I have an entity id that I select via a checkbox. Then I need to pass this selected ID value to the update method in the java code. How should I do it?
from the main jsp to jsp update I switch with
function updateCat() {
window.location.href = "http://localhost:8080/Cats_war/jsp/update.jsp?catId=" + document.querySelector('.messageCheckbox:checked').value;
}
can't get id from url