ClassCastException trying to invoke EJB from Undertow Handler in JBoss EAP 7

Issue

• We have an Undertow Handler which tries to invoke an EJB when the handler is handling a web request.

 java.lang.ClassCastException: com.sun.proxy.$Proxy49 cannot be cast to com.jboss.examples.ejb.Hello
    at com.jboss.examples.client.HelloClient.callEJB(HelloClient.java:52)
    at com.redhat.eap7.undertow.ExampleHandler.handleRequest(ExampleHandler.java:25)
    at io.undertow.server.handlers.SetHeaderHandler.handleRequest(SetHeaderHandler.java:90)
    at io.undertow.server.handlers.SetHeaderHandler.handleRequest(SetHeaderHandler.java:90)

The Handler looks like:

public class ExampleHandler implements HttpHandler {
...
   @Override
    public void handleRequest(final HttpServerExchange exchange) throws Exception {
        log.info("requestPath: " + exchange.getRequestPath());
        try {
           log.info("Using HelloClient to lookup and invoke an EJB");
           HelloClient helloClient = new HelloClient();
           String response = helloClient.callEJB();
           log.info("helloClient ejb response: " + response);
        } catch(Throwable t) {
           t.printStackTrace();
        }
        next.handleRequest(exchange);
    }   
...