[ARTEMIS-1998] NPE in MQTTProtocolManager.isClientConnected

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Duplicate
• Affects Version/s: 2.4.0, 2.6.2
• Component/s: MQTT
• Assignee: Unassigned
• Reporter: Assen Sharlandjiev
• Created: 31/Jul/18 08:13
• Updated: 10/Jan/20 20:12
• Resolved: 10/Jan/20 20:12

Description

I've encountered the following unhandled null pointer exception

2018-05-24 07:02:52.632 WARN 5030 --- [mpl$5@7c3e4b1a)] o.a.a.a.utils.actors.OrderedExecutor : null java.lang.NullPointerException: null at org.apache.activemq.artemis.core.protocol.mqtt.MQTTProtocolManager.isClientConnected(MQTTProtocolManager.java:182) at org.apache.activemq.artemis.core.protocol.mqtt.MQTTConnectionManager.disconnect(MQTTConnectionManager.java:150) at org.apache.activemq.artemis.core.protocol.mqtt.MQTTFailureListener.connectionFailed(MQTTFailureListener.java:37) at org.apache.activemq.artemis.core.protocol.mqtt.MQTTConnection.fail(MQTTConnection.java:146) at org.apache.activemq.artemis.core.remoting.server.impl.RemotingServiceImpl$FailureCheckAndFlushThread$2.run(RemotingServiceImpl.java:734) at org.apache.activemq.artemis.utils.actors.OrderedExecutor.doTask(OrderedExecutor.java:42) at org.apache.activemq.artemis.utils.actors.OrderedExecutor.doTask(OrderedExecutor.java:31) at org.apache.activemq.artemis.utils.actors.ProcessorBase$ExecutorTask.run(ProcessorBase.java:53) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745)

Perhaps a null check should be added to the connectedClients.get(clientId).

Issue Links

• duplicates: ARTEMIS-1952 NPE logged at warn if MQTT subscriber disconnects abruptly