mqtt | 易学教程

Receiving MQTT message with Wildlfy 11 embedded Apache Artemis

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问题 I would like to receive MQTT messages in Wildfly 11 with the embedded Apache Artemis. Current state: I added the MQTT protocol support to the Wildfly embedded Apache Artemis (added the "missing" folder and artemis-mqtt-protocol-.jar and enabled the protocol in the module.xml) I am using the full standalone configuration and added acceptor for MTQQ: <subsystem xmlns="urn:jboss:domain:messaging-activemq:2.0"> <server name="default"> <remote-acceptor name="mqtt-acceptor" socket-binding="mqtt">

Interpreting an ANR stack trace

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问题 I'm working with an implementation of an MQTT client from the PAHO library in Android. Sometimes, the application locks up when it tried to publish a message (I think) and I can't figure out what's going on. I also apologize in advance for the all to long post. I really don't know what the important bits are and the SO "spoiler" tag >! wouldn't work to hide the details. The MQTT client is working in a separate thread but I'm calling the mqtt client instance from the UI thread. Perhaps this

How to properly use TLS 1.3 cipher suites in HiveMQ? (Getting a SSL exception: closing inbound before receiving peer's close_notify)

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问题 I want to use TLS 1.3 for my secure communication with HiveMQ. I've configured the HiveMQ community edition server config.xml file to specify to use TLS 1.3 cipher suites and I pointed it to the keystore containing a key pair for a 256-bit Elliptic curve key (EC NOT DSA) using the curve: secp256r1 (which is one of the few curves supported by TLS 1.3). The 256-bit key pair is for this TLS 1.3 cipher suite I want to use: TLS_AES_128_GCM_SHA256 . I'm also generated a 384-bit elliptic curve key

How to fix DaggerSingletonComponent not resolved in HiveMQ (MQTT protocol)

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问题 I'm trying to set create the client first to test that the MQTT works without errors then I will implement the connect() method. I downloaded the latest version of HiveMQ (an open source MQTT implementation done in Java) and after importing the project properly as a Gradle build in Eclipse and using GIT I was greeted with an error message. It said "DaggerSingletonComponent cannot be resolved." My program can't run at all. Link to the open source I downloaded: https://github.com/hivemq/hivemq

Trying to publish in messageArrived() with the Paho Client MqttCallback

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问题 I'm trying to publish the response to the incoming message in messageArrived(...) . But the publish hang and the next line: logOutgoingMessage(topic, message) is never called... At the end i get a deadlock and the client disconnect. Here is my code: @Startup @Singleton public class AppliMqttClient implements MqttCallback { @EJB private AppliFacade facade; @PostConstruct public void start() { try { // connection options connOpts = new MqttConnectOptions(); connOpts.setKeepAliveInterval(120);

Spring integration MQTT publish & subscribe to multiple topics

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问题 I am trying to build an application which subscribes to multiple mqtt topics, get the information, process it and form xmls and upon processing trigger an event so that these can be sent to some cloud server and the successful response from there to be sent back to the mqtt channel. <int-mqtt:message-driven-channel-adapter id="mqttAdapter" client-id="${clientId}" url="${brokerUrl}" topics="${topics}" channel="startCase" auto-startup="true" /> <int:channel id="startCase" /> <int:service

Reconnecting from Airplane Mode with MQTT Android Service

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问题 I am implementing the Dale Lane MQTT Android Service Example found here http://dalelane.co.uk/blog/?p=1599, the example is working pretty well for my specific purpose, but I am dealing with 1 issue that I cannot seem to resolve. After testing rather extensively, I have found that the service does not reconnect after the phone has completely lost connection. For example, if the phone is placed in Airplane Mode and then taken out of Airplane mode, the service will continue to try to

Mqtt Qos 深度解读

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1.QoS含义： Quality of Service,服务质量 2.作用域发布者的Qos 订阅者的Qos 3.等级与作用 level 0：最多一次的传输 level 1：至少一次的传输，(鸡肋) level 2：只有一次的传输 4.交互过程 qos0 对于qos1而言，对于client而言，有且仅发一次publish包，对于broker而言，有且仅发一次publish，简而言之，就是仅发一次包，是否收到完全不管，适合那些不是很重要的数据。 qos0.png qos1 对于qos0而言，这个交互就是多了一次ack的作用，但是会有个问题，尽管我们可以通过确认来保证一定收到客户端或服务器的message，但是我们却不能保证message仅有一次，也就是当client没收到service的puback或者service没有收到client的puback，那么就会一直发送publisher 流程：（publisher -> broker） publisher store msg -> publish ->broker （传递message） broker -> puback -> publisher delete msg （确认传递成功）注意： publisher必须保存msg，这样才能在重发 publisher如果在一定时间或socket断开等异常情况，会继续重发msg

AWS IoT Python SDK and asyncio

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问题 I need to use AWS IoT MQTT service. I am doing some experimenting with https://github.com/aws/aws-iot-device-sdk-python currently. My application will be using websockets to communicate with another service, and then publish / subscribe to MQTT topics to forward / receive messages. Is it likely that this library will be blocking code execution? I still try to get my head around asyncio, and not sure what things I should be looking out for. How do I know if it will cause problems? I believe I

KURA: how to change the MQTT messages format

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问题 The KURA MQTT cloud client publishes messages respecting the following formula (more details): #account-name/#client-id/#API-ID/topic I want to send MQTT messages with my own format, I dont want to send the account name and the client id in the MQTT message. How can I do that? I already tried to change the configuration in the KURA web interface -> MQTTData transport and I have deleted the content of "lwt.topic" but without success. 回答1: Use the DataService directly. Ask OSGi to inject the