Atmosphere error when using custom vaadin.urlMapping with a space char

[mcollovati]

When using a custom URL mapping for Vaadin servlet containing a space (e.g. vaadin.urlMapping=/my ui/*), an Atmosphere error is logged in the server console at startup

2026-01-26T10:26:59.192+01:00  WARN 110001 --- [io-8080-exec-10] o.a.websocket.DefaultWebSocketProcessor  : Failed invoking AtmosphereFramework.doCometSupport()

org.atmosphere.cpr.AtmosphereMappingException: No AtmosphereHandler maps request for /my ui/VAADIN/push
	at org.atmosphere.cpr.AsynchronousProcessor.map(AsynchronousProcessor.java:391) ~[atmosphere-runtime-3.0.5.slf4jvaadin1.jar:3.0.5.slf4jvaadin1]
	at org.atmosphere.cpr.AsynchronousProcessor.action(AsynchronousProcessor.java:172) ~[atmosphere-runtime-3.0.5.slf4jvaadin1.jar:3.0.5.slf4jvaadin1]
	at org.atmosphere.cpr.AsynchronousProcessor.suspended(AsynchronousProcessor.java:103) ~[atmosphere-runtime-3.0.5.slf4jvaadin1.jar:3.0.5.slf4jvaadin1]
	at org.atmosphere.container.Servlet30CometSupport.service(Servlet30CometSupport.java:67) ~[atmosphere-runtime-3.0.5.slf4jvaadin1.jar:3.0.5.slf4jvaadin1]
	at org.atmosphere.cpr.AtmosphereFramework.doCometSupport(AtmosphereFramework.java:2284) ~[atmosphere-runtime-3.0.5.slf4jvaadin1.jar:3.0.5.slf4jvaadin1]
	at org.atmosphere.websocket.DefaultWebSocketProcessor.dispatch(DefaultWebSocketProcessor.java:574) ~[atmosphere-runtime-3.0.5.slf4jvaadin1.jar:3.0.5.slf4jvaadin1]
	at org.atmosphere.websocket.DefaultWebSocketProcessor.open(DefaultWebSocketProcessor.java:213) ~[atmosphere-runtime-3.0.5.slf4jvaadin1.jar:3.0.5.slf4jvaadin1]
	at org.atmosphere.container.JSR356Endpoint.onOpen(JSR356Endpoint.java:254) ~[atmosphere-runtime-3.0.5.slf4jvaadin1.jar:3.0.5.slf4jvaadin1]
	at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.init(WsHttpUpgradeHandler.java:131) ~[tomcat-embed-websocket-11.0.15.jar:11.0.15]
	at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:945) ~[tomcat-embed-core-11.0.15.jar:11.0.15]
	at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1778) ~[tomcat-embed-core-11.0.15.jar:11.0.15]
	at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52) ~[tomcat-embed-core-11.0.15.jar:11.0.15]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:946) ~[tomcat-embed-core-11.0.15.jar:11.0.15]
	at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:480) ~[tomcat-embed-core-11.0.15.jar:11.0.15]
	at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:57) ~[tomcat-embed-core-11.0.15.jar:11.0.15]
	at java.base/java.lang.Thread.run(Thread.java:1583) ~[na:na]

[mcollovati]

It looks like Atmosphere does not support spaces in mapping; the default mapping regex, defined in AtmosphereFramework, is "[a-zA-Z0-9-&.*_~=@;\\?]+". This can be changed by setting the org.atmosphere.cpr.mappingRegex property, but it currently does not work because in PushRequestHandler the AtmosphereFramework.addAtmosphereHandler(...) method is called before atmosphere reads the property value, so it uses the default.

This might be fixed by implementing #22568.
Another solution could be to move the addAtmosphereHandler() call after AtmosphereFramework.init() is invoked.