HTML / CSS / JavaScript works on the client side. Java / JSP runs on the server side. Client and server are two different environments that typically run on physically different computers that are connected to each other by a network with a communication protocol that is HTTP.
URL- , Java/JSP HTML/CSS/JS . (webbrowser) HTML/CSS/JS.
, , JavaScript / Java/JSP - HTTP- . : window.location GET form.submit() GET POST XMLHttpRequest#send() (aaaxical) .
JavaScript . HTML- .
<a href="page.jsp">link</a>
<form action="page.jsp">
<input type="submit">
</form>
JSP . - JSP, URL- <a href="page">, , , JSP,
request.getRequestDispatcher("/WEB-INF/page.jsp").forward(request, response);
Java/JSP JavaScript, .