java - nginx affects request value

Question

After passing the nginx proxy, the value of request.getSession(true).getServletContext() is null. If you directly access tomcat with IP and port, you can get the path. Is there any expert who has encountered this problem?
someone said:

proxy_set_header       Host $host;   //解决getRequestURL、getServerName、getServerPort

But proxy_set_header has been added

Answer 1

Try using request.getServletContext()