When trying to set the character encoding of the HTTP response, the encoding stays null.

This is our filter implementation:

public void doFilter(HttpServletRequest request, HttpServletResponse response, HttpSession session,
FilterChain chain) throws ServletException, IOException
{
System.out.println("encoding is " + request.getCharacterEncoding());
if (request.getCharacterEncoding() == null)

{ request.setCharacterEncoding("UTF-8"); }

if (request.getCharacterEncoding() == null)

{ System.out.println("could not set encoding"); Thread.dumpStack(); }

chain.doFilter(request, response);
}

The stack trace implies that there is only undertow beneath us Some element in the chain has already touched the response.

could not set encoding
java.lang.Exception: Stack trace
at java.lang.Thread.dumpStack(Thread.java:1342)
at de.mdkgmbh.sp.MdkCharacterEncodingFilter.doFilter(MdkCharacterEncodingFilter.java:24)
at org.omnifaces.filter.HttpFilter.doFilter(HttpFilter.java:75)
at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:56)
at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:132)
at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:85)
at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:59)
at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:81)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:25)
at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:113)
at io.undertow.security.handlers.AuthenticationCallHandler.handleRequest(AuthenticationCallHandler.java:52)
at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:45)
at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:65)
at io.undertow.security.handlers.SecurityInitialHandler.handleRequest(SecurityInitialHandler.java:70)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:25)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:25)
at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:218)
at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:205)
at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:69)
at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:134)
at io.undertow.server.HttpHandlers.executeRootHandler(HttpHandlers.java:36)
at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:619)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:722)

We need a solution for this, as we rely on UTF-8.

We have found no way to configure the listener either, seeing that the old JBoss Web way doesn't work anymore (WFLY-2276)