Collaborative view grid broadcast problem

Danko1 · January 11, 2019, 1:57pm

Hi everyone,

I’m trying to send grid broadcast to all registered views. Broadcast happens, but only after I click somewhere on grid. Also, when UI is refreshed I got RuntimeException. I’m using Vaadin Flow 12.0.3.

I tried several different approaches to this problem, but all of them results in same RuntimeException and I always have to click somewhere to update to happen.

Does anyone have any idea what might cause this problem?

My Broadcaster class is:


import com.vaadin.flow.component.UI;

import lombok.extern.slf4j.Slf4j;

import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

@Slf4j
public class Broadcaster {

    static ExecutorService executorService = Executors.newSingleThreadExecutor();

    static private Map<UI, BroadcastListener> listeners = new HashMap<>();

    public static synchronized void register( UI listener, BroadcastListener broadcastListener) {
        listeners.put(listener, broadcastListener);
        log.info("added {}" , listener.getSession().getSession().getId());
    }

    public static synchronized void unregister(UI ui, BroadcastListener broadcastListener) {
        listeners.remove(ui,broadcastListener);
    }

    public static synchronized void broadcast(String message) {
        for (Map.Entry<UI, BroadcastListener> pair : listeners.entrySet()) {
            executorService.execute(() ->
                    pair.getValue().receiveBroadcast("")
            );
        }
    }
}

BroadcasterListener interface:

public interface BroadcastListener {
        void receiveBroadcast(String message);
}

View that implements BroadcastListener override those methods:

UI currentUi;

    @Override
    protected void onAttach(AttachEvent attachEvent) {
        getUI().get().navigate("requests");
        currentUi = attachEvent.getUI();
        Broadcaster.register(currentUi, this);
    }

    @Override
    protected void onDetach(DetachEvent detachEvent) {
        Broadcaster.unregister(detachEvent.getUI(),this);
    }


    @Override
    public void receiveBroadcast(String message) {
        getUI().get().access(() -> {
            Notification.show("Updating");
            grid.getDataCommunicator().getKeyMapper().removeAll();
            grid.getDataCommunicator().getDataProvider().refreshAll();
            grid.getDataProvider().refreshAll();
            grid.setItems(repository.findRequestDocuments(requestStatusList));
            grid.getDataCommunicator().reset();

        });
    }

RuntimeException:

java.lang.RuntimeException: java.lang.IllegalStateException: Unknown key: 1
	at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.invokeMethod(PublishedServerEventHandlerRpcHandler.java:174) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.invokeMethod(PublishedServerEventHandlerRpcHandler.java:129) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.handleNode(PublishedServerEventHandlerRpcHandler.java:117) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.rpc.AbstractRpcInvocationHandler.handle(AbstractRpcInvocationHandler.java:64) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.ServerRpcHandler.handleInvocationData(ServerRpcHandler.java:379) [flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.ServerRpcHandler.lambda$handleInvocations$0(ServerRpcHandler.java:368) [flow-server-1.2.3.jar:1.2.3]

	at java.base/java.util.ArrayList.forEach(ArrayList.java:1378) ~[na:na]

	at com.vaadin.flow.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:368) [flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:310) [flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:89) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.VaadinService.handleRequest(VaadinService.java:1533) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.VaadinServlet.service(VaadinServlet.java:227) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.spring.SpringServlet.service(SpringServlet.java:65) ~[vaadin-spring-10.1.1.jar:na]

	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:728) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:470) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:356) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:316) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.servlet.mvc.ServletForwardingController.handleRequestInternal(ServletForwardingController.java:141) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:177) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:52) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:158) ~[spring-boot-actuator-2.0.3.RELEASE.jar:2.0.3.RELEASE]

	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:126) ~[spring-boot-actuator-2.0.3.RELEASE.jar:2.0.3.RELEASE]

	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:111) ~[spring-boot-actuator-2.0.3.RELEASE.jar:2.0.3.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:90) ~[spring-boot-actuator-2.0.3.RELEASE.jar:2.0.3.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:119) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:170) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:200) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:66) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:357) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:270) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1135) ~[na:na]

	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[na:na]

	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at java.base/java.lang.Thread.run(Thread.java:844) ~[na:na]

Caused by: java.lang.IllegalStateException: Unknown key: 1
	at com.vaadin.flow.component.grid.Grid.findByKey(Grid.java:2514) ~[vaadin-grid-flow-2.1.3.jar:na]

	at com.vaadin.flow.component.grid.Grid.select(Grid.java:2503) ~[vaadin-grid-flow-2.1.3.jar:na]

	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]

	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]

	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]

	at java.base/java.lang.reflect.Method.invoke(Method.java:564) ~[na:na]

	at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.invokeMethod(PublishedServerEventHandlerRpcHandler.java:167) ~[flow-server-1.2.3.jar:1.2.3]

	... 109 common frames omitted

2019-01-11 14:42:25.107 ERROR 740 --- [io-8084-exec-10]
 c.v.flow.server.DefaultErrorHandler      : 

java.lang.RuntimeException: java.lang.NullPointerException: DataCommunicator can not refresh null object
	at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.invokeMethod(PublishedServerEventHandlerRpcHandler.java:174) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.invokeMethod(PublishedServerEventHandlerRpcHandler.java:129) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.handleNode(PublishedServerEventHandlerRpcHandler.java:117) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.rpc.AbstractRpcInvocationHandler.handle(AbstractRpcInvocationHandler.java:64) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.ServerRpcHandler.handleInvocationData(ServerRpcHandler.java:379) [flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.ServerRpcHandler.lambda$handleInvocations$0(ServerRpcHandler.java:368) [flow-server-1.2.3.jar:1.2.3]

	at java.base/java.util.ArrayList.forEach(ArrayList.java:1378) ~[na:na]

	at com.vaadin.flow.server.communication.ServerRpcHandler.handleInvocations(ServerRpcHandler.java:368) [flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.ServerRpcHandler.handleRpc(ServerRpcHandler.java:310) [flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:89) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:40) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.VaadinService.handleRequest(VaadinService.java:1533) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.server.VaadinServlet.service(VaadinServlet.java:227) ~[flow-server-1.2.3.jar:1.2.3]

	at com.vaadin.flow.spring.SpringServlet.service(SpringServlet.java:65) ~[vaadin-spring-10.1.1.jar:na]

	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:728) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:470) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:356) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:316) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.servlet.mvc.ServletForwardingController.handleRequestInternal(ServletForwardingController.java:141) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:177) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:52) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:877) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at javax.servlet.http.HttpServlet.service(HttpServlet.java:661) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:158) ~[spring-boot-actuator-2.0.3.RELEASE.jar:2.0.3.RELEASE]

	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:126) ~[spring-boot-actuator-2.0.3.RELEASE.jar:2.0.3.RELEASE]

	at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:111) ~[spring-boot-actuator-2.0.3.RELEASE.jar:2.0.3.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:90) ~[spring-boot-actuator-2.0.3.RELEASE.jar:2.0.3.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:320) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:127) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:91) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:119) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:137) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:111) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:170) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:63) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:200) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:116) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.header.HeaderWriterFilter.doFilterInternal(HeaderWriterFilter.java:66) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:105) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:56) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:334) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:215) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:178) ~[spring-security-web-5.0.6.RELEASE.jar:5.0.6.RELEASE]

	at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:357) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:270) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.7.RELEASE.jar:5.0.7.RELEASE]

	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1468) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1135) ~[na:na]

	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[na:na]

	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-8.5.31.jar:8.5.31]

	at java.base/java.lang.Thread.run(Thread.java:844) ~[na:na]

Caused by: java.lang.NullPointerException: DataCommunicator can not refresh null object
	at java.base/java.util.Objects.requireNonNull(Objects.java:246) ~[na:na]

	at com.vaadin.flow.data.provider.DataCommunicator.refresh(DataCommunicator.java:186) ~[flow-data-1.2.3.jar:1.2.3]

	at com.vaadin.flow.component.grid.Grid$AbstractGridExtension.refresh(Grid.java:809) ~[vaadin-grid-flow-2.1.3.jar:na]

	at com.vaadin.flow.component.grid.Grid$DetailsManager.setDetailsVisibleFromClient(Grid.java:944) ~[vaadin-grid-flow-2.1.3.jar:na]

	at com.vaadin.flow.component.grid.Grid$DetailsManager.access$500(Grid.java:846) ~[vaadin-grid-flow-2.1.3.jar:na]

	at com.vaadin.flow.component.grid.Grid.setDetailsVisible(Grid.java:2534) ~[vaadin-grid-flow-2.1.3.jar:na]

	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]

	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]

	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]

	at java.base/java.lang.reflect.Method.invoke(Method.java:564) ~[na:na]

	at com.vaadin.flow.server.communication.rpc.PublishedServerEventHandlerRpcHandler.invokeMethod(PublishedServerEventHandlerRpcHandler.java:167) ~[flow-server-1.2.3.jar:1.2.3]

	... 109 common frames omitted

Danko1 · January 14, 2019, 8:29am

I solved this, I was missing transport parameter inside @Push annotation.
@Push(transport=Transport.WEBSOCKET_XHR)

ollit.1 · January 14, 2019, 9:39am

That’s odd, WEBSOCKET_XHR should be the default transport:

public @interface Push {

[...]


     /**
     * Transport type used for the push for the annotated root navigation target (or custom UI). The
     * default transport type when this annotation is present is
     * {@link Transport#WEBSOCKET_XHR}.
     *
     * @return the transport type to use
     */
    Transport transport() default Transport.WEBSOCKET_XHR;

Danko1 · January 14, 2019, 10:24am

Hi Olli,

you’re right. I changed to @Push and I have the same result.
I obviously changed something else but didn’t register that it made the change.

Thank you.

IE1 · June 11, 2019, 12:47am

Danko Pavlinovic:
Hi Olli,

you’re right. I changed to @Push and I have the same result.
I obviously changed something else but didn’t register that it made the change.

Thank you.

Hi Danko,

We are facing this same problem. How did you solve the problem? Just put the @Push annotation? Which class do you declare it in? Your MainUI class?

Danko1 · June 11, 2019, 9:52am

Hi IE A,

My main view class is anotated with @Push.
@Push
public class MainView extends VerticalLayout implements RouterLayout, BeforeEnterObserver {…}

Class that implements BroadcastListener looks like this:
@Route(value = “classa”, layout = MainView.class)
public class ClassA extends VerticalLayout implements BroadcastListener, RouterLayout, HasStyle {

@Override
protected void onAttach(AttachEvent attachEvent) {
    try {
        getUI().get().navigate("classa");
        refresh();
        currentUi = attachEvent.getUI();
        Broadcaster.register(currentUi, this);
    } catch (Exception e) {
        log.info("on attach exception");
    }
}

@Override
protected void onDetach(DetachEvent detachEvent) {
    currentPage = 0;
    Broadcaster.unregister(detachEvent.getUI(), this);
}

@Override
public void receiveBroadcast(String message) {
    getUI().get().access(() -> {
            grid.getDataCommunicator().getKeyMapper().removeAll();
            grid.getDataCommunicator().getDataProvider().refreshAll();
            grid.getDataProvider().refreshAll();
            grid.setItems(repository.findAll());
            grid.getDataCommunicator().reset();      
    });
}

}

If you want to broadcast some change to all other users you just need to call Broadcaster.broadcast(“”);
I hope this helps.

Danko

Armando28 · October 15, 2020, 7:18pm

IE A:

Danko Pavlinovic:
Hi Olli,

you’re right. I changed to @Push and I have the same result.
I obviously changed something else but didn’t register that it made the change.

Thank you.

Hi Danko,

We are facing this same problem. How did you solve the problem? Just put the @Push annotation? Which class do you declare it in? Your MainUI class?

I have the same problem I want to send a notification but doesn´t work , I have to click so that it shows notification