How to enable SSE in Meecrowave?

Question

How can I enable SSE in Meecrowave (1.2.4)?

I added dependency for org.apache.cxf:cxf-rt-rs-sse:3.2.7 but I get NPE in resource method:

java.lang.NullPointerException: null
at org.apache.cxf.jaxrs.impl.AsyncResponseImpl.initContinuation(AsyncResponseImpl.java:306) ~[cxf-rt-frontend-jaxrs-3.2.7.jar:3.2.7]
at org.apache.cxf.jaxrs.impl.AsyncResponseImpl.<init>(AsyncResponseImpl.java:68) ~[cxf-rt-frontend-jaxrs-3.2.7.jar:3.2.7]
at org.apache.cxf.jaxrs.sse.SseEventSinkContextProvider.createContext(SseEventSinkContextProvider.java:47) ~[cxf-rt-rs-sse-3.2.7.jar:3.2.7]
at org.apache.cxf.jaxrs.sse.SseEventSinkContextProvider.createContext(SseEventSinkContextProvider.java:35) ~[cxf-rt-rs-sse-3.2.7.jar:3.2.7]
at org.apache.cxf.jaxrs.utils.JAXRSUtils.createContextValue(JAXRSUtils.java:1146) ~[cxf-rt-frontend-jaxrs-3.2.7.jar:3.2.7]
at org.apache.cxf.jaxrs.utils.JAXRSUtils.processParameter(JAXRSUtils.java:874) ~[cxf-rt-frontend-jaxrs-3.2.7.jar:3.2.7]
at org.apache.cxf.jaxrs.utils.JAXRSUtils.processParameters(JAXRSUtils.java:808) [cxf-rt-frontend-jaxrs-3.2.7.jar:3.2.7]
at org.apache.cxf.jaxrs.interceptor.JAXRSInInterceptor.processRequest(JAXRSInInterceptor.java:214) [cxf-rt-frontend-jaxrs-3.2.7.jar:3.2.7]
at org.apache.cxf.jaxrs.interceptor.JAXRSInInterceptor.handleMessage(JAXRSInInterceptor.java:78) [cxf-rt-frontend-jaxrs-3.2.7.jar:3.2.7]
at org.apache.cxf.phase.PhaseInterceptorChain.doIntercept(PhaseInterceptorChain.java:308) [cxf-core-3.2.7.jar:3.2.7]
at org.apache.cxf.transport.ChainInitiationObserver.onMessage(ChainInitiationObserver.java:121) [cxf-core-3.2.7.jar:3.2.7]
at org.apache.cxf.transport.http.AbstractHTTPDestination.invoke(AbstractHTTPDestination.java:267) [cxf-rt-transports-http-3.2.7.jar:3.2.7]
at org.apache.cxf.transport.servlet.ServletController.invokeDestination(ServletController.java:234) [cxf-rt-transports-http-3.2.7.jar:3.2.7]
at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:208) [cxf-rt-transports-http-3.2.7.jar:3.2.7]
at org.apache.cxf.transport.servlet.ServletController.invoke(ServletController.java:160) [cxf-rt-transports-http-3.2.7.jar:3.2.7]
at org.apache.cxf.transport.servlet.CXFNonSpringServlet.invoke(CXFNonSpringServlet.java:216) [cxf-rt-transports-http-3.2.7.jar:3.2.7]
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.handleRequest(AbstractHTTPServlet.java:301) [cxf-rt-transports-http-3.2.7.jar:3.2.7]
at org.apache.cxf.transport.servlet.AbstractHTTPServlet.doGet(AbstractHTTPServlet.java:225) [cxf-rt-transports-http-3.2.7.jar:3.2.7]

I found and old thread about SSE in Meecrowave:

http://mail-archives.apache.org/mod_mbox/openwebbeans-user/201802.mbox/%3C147540348.1079544.1517463170730%40mail.yahoo.com%3E

but it doesn't seem relevant now because SSE was refactored in CXF 3.2.5:

http://cxf.apache.org/docs/sse.html

Answer 1

I found out that there was ServletFilter without asyncSupported=true. After I set asyncSupported on Filter to true, it worked.