I would like to obtain a unique identifier for every connection established to Tomcat. I am not talking about sessions or uniqueness of users (clients) but every connection. Say, client A sends one GET, then another. In my scenario these are two separate and unique connections.
Is there any variable or something that can play identifier role for such a connection in Tomcat ?
One option is to use a ServletFilter:
public class UniqueRequestFilter implements Filter { public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { String requestID = UUID.randomUUID().toString() //save to ThreadLocal... try { chain.doFilter(req, res); } finally { //remove from ThreadLocal } } public void init(FilterConfig config) throws ServletException { } public void destroy() { } } You will be able to get the request value from the ThreadLocal at any point in your application.
Jakarta Servlet 6.0 (c. 2022) adds a new method to the ServletRequest interface: getRequestId.
While you may have had to write your own request-id-generator in the past, you should now be able to rely on a container-agnostic feature in your web applications.
Servlet container has session tracking mechanism, usually its cookie with name "JSESSIONID", you can use it as session identifier. From servlet specification:
The standard name of the session tracking cookie must be JSESSIONID, which must be supported by all 3.0 compliant containers
More details can be found in servlet specification.
One solution could perhaps be to create a new session on every request?
A way to achieve that would be to set true in session-config/cookie-config in web.xml (unless you are running a HTTPS connection)
