Java Springboot MQTT IoT AWS Connection lost, EOF Exception

Question

I am using Java Springboot and working with AWS IoT. I have create an AWS IoT thing and am trying to connect using the provided aws sdk. I am not familiar with MQTT as this is my first time and am not sure why the connection is lost. Client endpoint is obtained from aws console by selecting the Thing and then interact tab. I have generated certificates and keys using the automatic cert generation for aws as well. I am only testing an initial connection so there should not be other devices connecting.

org.eclipse.paho.client.mqttv3.MqttException: Connection lost at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:190) ~[org.eclipse.paho.client.mqttv3-1.2.2.jar:na] at java.base/java.lang.Thread.run(Thread.java:832) ~[na:na] Caused by: java.io.EOFException: null at java.base/java.io.DataInputStream.readByte(DataInputStream.java:271) ~[na:na] at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:92) ~[org.eclipse.paho.client.mqttv3-1.2.2.jar:na] at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:137) ~[org.eclipse.paho.client.mqttv3-1.2.2.jar:na] ... 1 common frames omitted

I would like to find out what are the possible reasons for an MQTT connection lost and is there a way I could debug to find out why connection is lost.

Answer 1

I also get the same exception while connecting with IOT over mqtt.

! java.io.EOFException: null
! at java.io.DataInputStream.readByte(DataInputStream.java:267) ~[na:1.8.0_242]
! at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:92) ~[org.eclipse.paho.client.mqttv3-1.2.2.jar:na]
! at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:137) [org.eclipse.paho.client.mqttv3-1.2.2.jar:na]
! ... 1 common frames omitted
! Causing: org.eclipse.paho.client.mqttv3.MqttException: Connection lost
! at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:190) [org.eclipse.paho.client.mqttv3-1.2.2.jar:na]
! at java.lang.Thread.run(Thread.java:748) [na:1.8.0_242]

and the error got resolved when i generated unique clientId for each client connecting with mqtt.