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via Stack Overflow by aryanRaj_kary
, 5 months ago
This exception has no message.
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via Atlassian JIRA by Steve Smith [SYD/AMS/LHR], 2 years ago
java.lang.NullPointerException: 	at java.util.concurrent.ConcurrentHashMap.get(ConcurrentHashMap.java:936)	at org.springframework.session.web.socket.handler.WebSocketRegistryListener.registerWsSession(WebSocketRegistryListener.java:118)	at org.springframework.session.web.socket.handler.WebSocketRegistryListener.afterConnectionEstablished(WebSocketRegistryListener.java:86)	at org.springframework.session.web.socket.handler.WebSocketRegistryListener.onApplicationEvent(WebSocketRegistryListener.java:67)	at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:166)	at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:138)	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:382)	at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:336)