Error when init Atmosphere on Tomcat 7

General
1

Hi all,

my Vaadin 8 application (version 8.1.5) is throwing an exception when it executes on Tomcat 7 (version 7.0.69) - but apparently it still works.

SEVERE: Unable to load class {}. Please make sure you have properly installed Atmosphere http://goo.gl/KEi8pc java.lang.NoClassDefFoundError: org/apache/catalina/comet/CometEvent at org.atmosphere.container.Tomcat7CometSupport.<init>(Tomcat7CometSupport.java:62) at org.atmosphere.container.Tomcat7AsyncSupportWithWebSocket.<init>(Tomcat7AsyncSupportWithWebSocket.java:52) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.atmosphere.cpr.DefaultAsyncSupportResolver.newCometSupport(DefaultAsyncSupportResolver.java:253) at org.atmosphere.cpr.AtmosphereFramework.doInitParams(AtmosphereFramework.java:1457) at org.atmosphere.cpr.AtmosphereFramework.doInitParams(AtmosphereFramework.java:1432) at org.atmosphere.cpr.AtmosphereFramework.init(AtmosphereFramework.java:878) at org.atmosphere.cpr.AtmosphereFramework.init(AtmosphereFramework.java:838) at com.vaadin.server.communication.PushRequestHandler.initAtmosphere(PushRequestHandler.java:216) at com.vaadin.server.communication.PushRequestHandler.<init>(PushRequestHandler.java:84) at com.vaadin.server.VaadinServletService.createRequestHandlers(VaadinServletService.java:53) at com.vaadin.server.VaadinService.init(VaadinService.java:196) at com.vaadin.server.VaadinServlet.createServletService(VaadinServlet.java:334) at com.vaadin.server.VaadinServlet.init(VaadinServlet.java:228) at org.apache.catalina.core.StandardWrapper.initServlet(StandardWrapper.java:1282) at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1195) at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:866) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:134) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:956) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:436) at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1078) at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:625) at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Thread.java:745) Does anyone have experienced the same situation? I believe that it is related to my web.xml configuration:

<context-param>
    <param-name>productionMode</param-name>
    <param-value>false</param-value>
</context-param>

<servlet>
    <servlet-name>MyServlet</servlet-name>
    <servlet-class>com.example.MyServlet</servlet-class>
    <init-param>
        <param-name>UI</param-name>
        <param-value>com.example.MyUI</param-value>
    </init-param>
    <init-param>
        <param-name>widgetset</param-name>
        <param-value>AppWidgetset</param-value>
    </init-param>
    <init-param>
        <param-name>org.atmosphere.cpr.asyncSupport</param-name>
        <param-value>org.atmosphere.container.Tomcat7AsyncSupportWithWebSocket</param-value>
    </init-param>
    <async-supported>true</async-supported>
</servlet>

<session-config>
    <session-timeout>10000</session-timeout>
</session-config>

<servlet-mapping>
    <servlet-name>MyServlet</servlet-name>
    <url-pattern>/vaadin/*</url-pattern>
</servlet-mapping>

<servlet-mapping>
    <servlet-name>MyServlet</servlet-name>
    <url-pattern>/VAADIN/*</url-pattern>
</servlet-mapping>
2

Hi Felipe,

You have “async-supported” set to true. Did you try to run the app withouth the “org.atmosphere.cpr.asyncSupport” init-param in your web.xml?

BR,
Goran

3

I’d strongly recommend upgrading to a more recent version of Tomcat, if possible, especially since you’re using Push - the WebSockets support has been completely rewritten in Tomcat 8 and there are lots of bugfixes in there.

Best regards,

Olli

4

Hi Olli, in my case it’s not viable, because this is our client’s environment and they don’t aim to change that soon.

I read something about putting an atmosphere compatibility jar to Tomcat 7.

<dependency> <groupId>org.atmosphere</groupId> <artifactId>atmosphere-compat-tomcat7</artifactId> <version>2.0.1</version> </dependency> Do you know something about it? I’ll try it now and after I will post the result.

5

Hi Goran, yes I did, but it doens’t worked. As I said to Olli, I’ll put that tomcat7 compatibility jar just to give it a try.

6

Hey Guys,

with the compatibility library (
atmosphere-compat-tomcat7
) the error stopped occuring.

PS: atmosphere’s official website has some recommendations about compatibility with different servers. Follow the link for reference:
https://github.com/Atmosphere/atmosphere/wiki/Installing-AtmosphereServlet-with-or-without-native-support

Thank so much for your support!

7

Great to hear you got it working! The compatibility library does sound like the right way to go.

-Olli