ConnectionState.getNextInvocationId() Null pointer exception

[mashahbazi]

After I figured the error #6898 and as said it's error fixed in 3.0.0-preview3. but now is start to send NullPointerException on invoke
Attempt to invoke virtual method 'java.lang.String com.microsoft.signalr.HubConnection$ConnectionState.getNextInvocationId()' on a null object reference
I check hubConnectionState to be HubConnectionState.CONNECTED before calling method invoke.

[analogrelay]

cc @mikaelm12

Smells like a race...

@mashahbazi can you post the specific version of com.microsoft.signalr:signalr you are using?

[mikaelm12]

Yeah, please post the version of the Java client that you are using, If you're not on preview 6, then I'd first recommend updating to use that. Preview 7 is coming out next week and it also has some updates to the Java client but they shouldn't directly effect the scenario you mention.

Preview 6 version com.microsoft.signalr:signalr:3.0.0-preview6.19307.2 https://search.maven.org/artifact/com.microsoft.signalr/signalr/3.0.0-preview6.19307.2/jar
Note this when looking for the jars on search.maven.org this wont come up as the latest version since we changed our versioning to use dots rather than dashes.

[mikaelm12]

And if you could also include the full stack trace that would be helpful as well!

[mashahbazi]

yeap, I'm update and my version is 3.0.0-preview6.19307.2. And I said my stack trace for you it's very simple.when you invoke it get null. this is fabric crashlytics log.
com.microsoft.signalr.HubConnection.invoke + 586 (HubConnection.java:586)
before this trace is in my code.

[mikaelm12]

After a quick investigation, it looks like we need some more locking. Moving this into preview 8