When calling a createSession on connection a java.lang.NullPointerException is thrown

java.lang.NullPointerException
	at org.apache.activemq.artemis.jms.client.ActiveMQConnection.createSessionInternal(ActiveMQConnection.java:619)
	at org.apache.activemq.artemis.jms.client.ActiveMQConnection.createQueueSession(ActiveMQConnection.java:435)

Looking at the code the same issue exist in EAP 7.3.0.GA with later version or Artemis. The NPE is caused by ClientSessionFactory.Impl.createSessionInternal() method returning null if a connection is already closed. This condition may be triggered if multiple threads are trying to use a connection. If one thread closes a connection while another is trying to create a session the NPE may be triggered.

I think it would be wise to check for null in

ActiveMQConnection.createSessionInternal()

before calling

session.addFailureListener(listener);

and throw an exception if it is.