title: Spring "The request was rejected because the URL was not normalized." How to tell what url was used?
body: <p>I'm getting a ton of errors in production for </p>
  
  <pre><code>org.springframework.security.web.firewall.RequestRejectedException: The request was rejected because the URL was not normalized.
  </code></pre>
  
  <p>Supposedly this is caused by a <code>//</code> in my urls, but I have no idea where they are coming from. How can I tell what url is causing this? Hard to fix when you don't know what's going on.</p>
  
  <p>I do realize that there is a related <a href="https://stackoverflow.com/questions/48453980/spring-5-0-3-requestrejectedexception-the-request-was-rejected-because-the-url">question</a>, but that doesn't address how to diagnose the problem URLs. It only addresses how to turn off the strict firewall.</p>