As I used to, I'am going to answer to myself ; it might help somebody.The problem comes from client side : the client store in cache (more precisely in cookies) the pages login.jsp and browse.jsp.So when we copy/paste the URL browse.jsp into the navigator, the navigator display the cached browse.jsp.To solve this problem, we need to force the navigator NOT TO CACHE the browse.jsp page (login.jsp is not important).Hence, we need to add at the begin of browse.jsp page the scriplet :
<%
response.addHeader("Pragma", "no-cache");
response.addHeader("Cache-Control", "no-cache");
response.addHeader("Cache-Control", "must-revalidate");
%>
and then we can see that in windows cookie, the browse.jsp doesn't appear anymore.