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fusesource / mqtt-client

A Java MQTT Client
http://mqtt-client.fusesource.org/
Apache License 2.0
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NullPointerExecption #94

Open QX-Zach opened 6 years ago

QX-Zach commented 6 years ago

E/AndroidRuntime: FATAL EXCEPTION: hawtdispatch-DEFAULT-2 Process: personal.zach.gprsdemo, PID: 18304 java.lang.NullPointerException: Attempt to invoke interface method 'boolean org.fusesource.hawtdispatch.transport.Transport.offer(java.lang.Object)' on a null object reference at org.fusesource.mqtt.client.CallbackConnection$7.run(CallbackConnection.java:450) at org.fusesource.hawtdispatch.transport.HeartBeatMonitor$3.run(HeartBeatMonitor.java:87) at org.fusesource.hawtdispatch.transport.HeartBeatMonitor$1.run(HeartBeatMonitor.java:65) at org.fusesource.hawtdispatch.internal.SerialDispatchQueue.run(SerialDispatchQueue.java:100) at org.fusesource.hawtdispatch.internal.pool.SimpleThread.run(SimpleThread.java:77)

laviua commented 6 years ago 
                                                           java.lang.NullPointerException
                                                               at org.fusesource.mqtt.codec.MQTTProtocolCodec.encode(MQTTProtocolCodec.java:70)
                                                               at org.fusesource.hawtdispatch.transport.AbstractProtocolCodec.write(AbstractProtocolCodec.java:139)
                                                               at org.fusesource.hawtdispatch.transport.TcpTransport.offer(TcpTransport.java:653)
                                                               at org.fusesource.mqtt.client.CallbackConnection.send(CallbackConnection.java:698)
                                                               at org.fusesource.mqtt.client.CallbackConnection.send(CallbackConnection.java:684)
                                                               at org.fusesource.mqtt.client.CallbackConnection.publish(CallbackConnection.java:630)
                                                               at org.fusesource.mqtt.client.CallbackConnection.publish(CallbackConnection.java:619)

The same. Issue appears only with callback connection type

during: nextWriteBuffer.write(digit); nextWriteBuffer is null

Jin-here commented 6 years ago

@laviua I have replace this sdk with paho.mqtt.java, and it works well.

laviua commented 6 years ago

@VolodymyrCj, yes, i know ) anyway thanks for you answer

QX-Zach commented 6 years ago

this because of the signal of wifi is not stable. mqtt will reconnect frequent，and cause the thread stack overflow. now,i use the following settings.

mqtt.setConnectAttemptsMax(10L); mqtt.setReconnectAttemptsMax(-1); mqtt.setReconnectDelay(100L); mqtt.setReconnectDelayMax(30000L); mqtt.setReconnectBackOffMultiplier(2);

but it does't work.

c2545500 commented 5 years ago

You can judge the network status And cancel the connection

你可以判断网络状态 并且取消连接