title: How can I log the Content-Type that Spring rejects with a 415 Unknown Media Type?
body: <p>I've got a basic Spring Boot app with a REST endpoint that is configured to receive POSTs with <code>Content-Type</code> = <code>application/json</code>.</p>
  
  <p>My external partner is posting me HTTP requests, but apparently with a different <code>Content-Type</code>, because my app rejects those requests with HTTP 415 Unsupported Media Type.</p>
  
  <p>Unfortunately, Spring's logs do not reveal what exactly the Content-Type is, and the external partner is currently unavailable for questions.</p>
  
  <p>Is there a way to crank up Spring's log level so the log also includes the received <code>Content-Type</code> that's being rejected?</p>