When I debug the process to reproduce the issue, I find that the Host of HttpServletRequest passed in /src/main/java/spark/embeddedserver/jetty/JettyHandler.doHandle() method is proxy.mydomain.com, which means it is not a bug in code.
After searching for answear, I find this link may help you understand the problem.
And add a test for request with X-Forwarded-Host.
When I debug the process to reproduce the issue, I find that the
Hostof HttpServletRequest passed in/src/main/java/spark/embeddedserver/jetty/JettyHandler.doHandle()method is proxy.mydomain.com, which means it is not a bug in code. After searching for answear, I find this link may help you understand the problem. And add a test for request with X-Forwarded-Host.