mqtt 是否能推送数据给多个客户端数据，一次多推。_course

如题所说，遇到一个bug W/System.err( 1904): Client is not connected (32104) W/System.err( 1904): at org.eclipse.paho.client.mqttv3.internal.ExceptionHelper.createMqttException(ExceptionHelper.java:27) W/System.err( 1904): at org.eclipse.paho.client.mqttv3.internal.ClientComms.internalSend(ClientComms.java:101) W/System.err( 1904): at org.eclipse.paho.client.mqttv3.internal.ClientComms.sendAndWait(ClientComms.java:111) W/System.err( 1904): at org.eclipse.paho.client.mqttv3.MqttClient.subscribe(MqttClient.java:588) W/System.err( 1904): at org.eclipse.paho.client.mqttv3.MqttClient.subscribe(MqttClient.java:482) W/System.err( 1904): at de.eclipsemagazin.mqtt.push.MQTTService$1.handleMessage(MQTTService.java:45) W/System.err( 1904): at android.os.Handler.dispatchMessage(Handler.java:102) W/System.err( 1904): at android.os.Looper.loop(Looper.java:136) W/System.err( 1904): at android.app.ActivityThread.main(ActivityThread.java:5017) W/System.err( 1904): at java.lang.reflect.Method.invokeNative(Native Method) W/System.err( 1904): at java.lang.reflect.Method.invoke(Method.java:515) W/System.err( 1904): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:788) W/System.err( 1904): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:604) W/System.err( 1904): at dalvik.system.NativeStart.main(Native Method) W/System.err( 1904): Timed out waiting for a response from the server (32000) W/System.err( 1904): at org.eclipse.paho.client.mqttv3.internal.ExceptionHelper.createMqttException(ExceptionHelper.java:27) W/System.err( 1904): at org.eclipse.paho.client.mqttv3.internal.ClientComms.connect(ClientComms.java:162) W/System.err( 1904): at org.eclipse.paho.client.mqttv3.MqttClient.connect(MqttClient.java:339) W/System.err( 1904): at de.eclipsemagazin.mqtt.push.MQTTService$3.run(MQTTService.java:111) W/System.err( 1904): at java.lang.Thread.run(Thread.java:841) D/dalvikvm( 599): GC_CONCURRENT freed 874K, 19% free 4489K/5488K, paused 27ms+5ms, total 84ms

adnroid 开发编译mqtt报错_course

android studio 下载并打开paho.mqtt.android 编译报错，我的gradle版本4.4 as版本3.1.3 下载地址https://github.com/eclipse/paho.mqtt.android 直接git到的原始的项目，打开编译就报错，我本地新建空内容项目都能编译成功，adnroid 开发编译mqtt报错× 报错如下： Cannot create variant 'android-lint' after configuration ':org.eclipse.paho.android.service:debugRuntimeElements' has been resolved  org.gradle.initialization.ReportedException: org.gradle.internal.exceptions.LocationAwareException: A problem occurred configuring project ':org.eclipse.paho.android.service'. at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:139) at org.gradle.initialization.DefaultGradleLauncher.executeTasks(DefaultGradleLauncher.java:109) at org.gradle.internal.invocation.GradleBuildController$1.call(GradleBuildController.java:78) at org.gradle.internal.invocation.GradleBuildController$1.call(GradleBuildController.java:75) at org.gradle.internal.work.DefaultWorkerLeaseService.withLocks(DefaultWorkerLeaseService.java:152) at org.gradle.internal.invocation.GradleBuildController.doBuild(GradleBuildController.java:100) at org.gradle.internal.invocation.GradleBuildController.run(GradleBuildController.java:75) at org.gradle.tooling.internal.provider.runner.BuildModelActionRunner.run(BuildModelActionRunner.java:53) at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35) at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35) 。。。 at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55) at java.lang.Thread.run(Thread.java:745) Caused by: org.gradle.internal.exceptions.LocationAwareException: A problem occurred configuring project ':org.eclipse.paho.android.service'. at org.gradle.initialization.DefaultExceptionAnalyser.transform(DefaultExceptionAnalyser.java:74) at org.gradle.initialization.MultipleBuildFailuresExceptionAnalyser.transform(MultipleBuildFailuresExceptionAnalyser.java:47) at org.gradle.initialization.StackTraceSanitizingExceptionAnalyser.transform(StackTraceSanitizingExceptionAnalyser.java:30) at org.gradle.initialization.DefaultGradleLauncher.doBuildStages(DefaultGradleLauncher.java:137) at org.gradle.initialization.DefaultGradleLauncher.executeTasks(DefaultGradleLauncher.java:109) at org.gradle.internal.invocation.GradleBuildController$1.call(GradleBuildController.java:78) at org.gradle.internal.invocation.GradleBuildController$1.call(GradleBuildController.java:75) at org.gradle.internal.work.DefaultWorkerLeaseService.withLocks(DefaultWorkerLeaseService.java:152) at org.gradle.internal.invocation.GradleBuildController.doBuild(GradleBuildController.java:100) at org.gradle.internal.invocation.GradleBuildController.run(GradleBuildController.java:75) at org.gradle.tooling.internal.provider.runner.BuildModelActionRunner.run(BuildModelActionRunner.java:53) at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35) at org.gradle.launcher.exec.ChainingBuildActionRunner.run(ChainingBuildActionRunner.java:35) at org.gradle.tooling.internal.provider.ValidatingBuildActionRunner.run(ValidatingBuildActionRunner.java:32) at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner$1.run(RunAsBuildOperationBuildActionRunner.java:43) at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336) at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328) at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199) at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110) at org.gradle.launcher.exec.RunAsBuildOperationBuildActionRunner.run(RunAsBuildOperationBuildActionRunner.java:40) 。。。 at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122) at org.gradle.launcher.daemon.server.exec.EstablishBuildEnvironment.doBuild(EstablishBuildEnvironment.java:82) at org.gradle.launcher.daemon.server.exec.BuildCommandOnly.execute(BuildCommandOnly.java:36) at org.gradle.launcher.daemon.server.api.DaemonCommandExecution.proceed(DaemonCommandExecution.java:122) at org.gradle.launcher.daemon.server.exec.StartBuildOrRespondWithBusy$1.run(StartBuildOrRespondWithBusy.java:50) at org.gradle.launcher.daemon.server.DaemonStateCoordinator$1.run(DaemonStateCoordinator.java:295) at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63) at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46) at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55) Caused by: org.gradle.api.ProjectConfigurationException: A problem occurred configuring project ':org.eclipse.paho.android.service'. at org.gradle.configuration.project.LifecycleProjectEvaluator.addConfigurationFailure(LifecycleProjectEvaluator.java:94) at org.gradle.configuration.project.LifecycleProjectEvaluator.notifyAfterEvaluate(LifecycleProjectEvaluator.java:89) 。。。 ... 62 more Caused by: org.gradle.api.InvalidUserCodeException: Cannot create variant 'android-lint' after configuration ':org.eclipse.paho.android.service:debugRuntimeElements' has been resolved at org.gradle.api.internal.artifacts.configurations.DefaultConfigurationPublications$ConfigurationVariantFactory.create(DefaultConfigurationPublications.java:158) at org.gradle.api.internal.artifacts.configurations.DefaultConfigurationPublications$ConfigurationVariantFactory.create(DefaultConfigurationPublications.java:151) at org.gradle.api.internal.FactoryNamedDomainObjectContainer.doCreate(FactoryNamedDomainObjectContainer.java:100) at org.gradle.api.internal.AbstractNamedDomainObjectContainer.create(AbstractNamedDomainObjectContainer.java:67) at com.android.build.gradle.internal.scope.VariantScopeImpl.lambda$publishArtifactToConfiguration$2(VariantScopeImpl.java:378) at org.gradle.api.internal.artifacts.configurations.DefaultConfigurationPublications.variants(DefaultConfigurationPublications.java:139) at com.android.build.gradle.internal.scope.VariantScopeImpl.publishArtifactToConfiguration(VariantScopeImpl.java:376) at com.android.build.gradle.internal.scope.VariantScopeImpl.publishIntermediateArtifact(VariantScopeImpl.java:347) at com.android.build.gradle.internal.scope.VariantScopeImpl.addTaskOutput(VariantScopeImpl.java:298) at com.android.build.gradle.internal.TaskManager.configureGlobalLintTask(TaskManager.java:536) at com.android.build.gradle.BasePlugin.createAndroidTasks(BasePlugin.java:7

java后台异步推送消息至服务器（mqtt paho）_course

web创建消息推送保存至数据库后，后台从数据库获取数据并异步推送；即每次获取一条数据推送，推送成功后再获取第二条数据推送，依此类推，当没有数据时处于睡眠状态。我该怎么实现。

用MQTTfx连接阿里云物联网平台，怎么一直MQTTException_course

我按官网格式配的设置，怎么就一直出MQTTException。  后面的用户名和密码也设置好了 ``` 2019-07-17 15:01:21,271 INFO --- BrokerConnectorController : onConnect 2019-07-17 15:01:21,272 INFO --- ScriptsController : Clear console. 2019-07-17 15:01:21,276 INFO --- MqttFX ClientModel : MqttClient with ID 5CD6367ZYS|securemode=3,signmethod=hmacsha1,timestamp=10| assigned. 2019-07-17 15:01:21,294 ERROR --- MqttFX ClientModel : Error when connecting org.eclipse.paho.client.mqttv3.MqttException: MqttException at org.eclipse.paho.client.mqttv3.internal.ExceptionHelper.createMqttException(ExceptionHelper.java:38) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] at org.eclipse.paho.client.mqttv3.internal.ClientComms$ConnectBG.run(ClientComms.java:715) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:?] at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:?] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(Unknown Source) ~[?:?] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) ~[?:?] at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:?] at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:?] at java.lang.Thread.run(Unknown Source) [?:?] Caused by: java.lang.IllegalArgumentException: hostname can&#39;t be null at java.net.InetSocketAddress.checkHost(Unknown Source) ~[?:?] at java.net.InetSocketAddress.<init>(Unknown Source) ~[?:?] at org.eclipse.paho.client.mqttv3.internal.TCPNetworkModule.start(TCPNetworkModule.java:76) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] at org.eclipse.paho.client.mqttv3.internal.ClientComms$ConnectBG.run(ClientComms.java:701) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] ... 7 more 2019-07-17 15:01:21,295 ERROR --- MqttFX ClientModel : Please verify your Settings (e.g. Broker Address, Broker Port & Client ID) and the user credentials! org.eclipse.paho.client.mqttv3.MqttException: MqttException at org.eclipse.paho.client.mqttv3.internal.ExceptionHelper.createMqttException(ExceptionHelper.java:38) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] at org.eclipse.paho.client.mqttv3.internal.ClientComms$ConnectBG.run(ClientComms.java:715) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:?] at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:?] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(Unknown Source) ~[?:?] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) ~[?:?] at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:?] at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:?] at java.lang.Thread.run(Unknown Source) [?:?] Caused by: java.lang.IllegalArgumentException: hostname can&#39;t be null at java.net.InetSocketAddress.checkHost(Unknown Source) ~[?:?] at java.net.InetSocketAddress.<init>(Unknown Source) ~[?:?] at org.eclipse.paho.client.mqttv3.internal.TCPNetworkModule.start(TCPNetworkModule.java:76) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] at org.eclipse.paho.client.mqttv3.internal.ClientComms$ConnectBG.run(ClientComms.java:701) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] ... 7 more 2019-07-17 15:01:21,301 INFO --- ScriptsController : Clear console. 2019-07-17 15:01:21,302 ERROR --- BrokerConnectService : MqttException ``` 这是连接后的log，萌新看不懂，求大佬解释

LinkIT One使用paho mqtt连接服务器失败_course

背景描述： 使用LinkIT One基于paho的mqtt客户端，当代码执行到rc=client.connect(data);，超时然后返回rc=-1。 测试连接的服务端包括IBM Watson、中移OneNet还有自己搭建的mosquitto，都是一样的错误。查了一下paho的实现代码，把MQTTClient.h中的connect实现改了一下就connect成功了，但subscribe又超时并返回错误了（如下所示）。 在网上查到了和我类似的错误，貌似LinkIT One并不能使用paho的mqtt。但将mqtt客户端换成pubsub后却能够正常工作。 下面是我的测试代码（mqtt服务器是本地局域网的mosquitto） ``` #include <LWiFi.h> #include <LWiFiClient.h> #include <IPStack.h> #include <Countdown.h> #include <MQTTClient.h> #define WIFI_AP "SSID" #define WIFI_PASSWORD "PASSWD" #define WIFI_AUTH LWIFI_WPA int port = 1883; char servername[]="10.214.149.119"; char clientName[] = "myaccount"; char topicName[] = "@tp"; char userName[] = "myaccount"; char password[] = "12345"; LWiFiClient tcpClient; IPStack ipstack(tcpClient); MQTT::Client<IPStack, Countdown, 200> client = MQTT::Client<IPStack, Countdown, 200>(ipstack); void messageArrived(MQTT::MessageData& md){ MQTT::Message &message = md.message; char res[100]; int len = message.payloadlen; strncpy(res, (char*)message.payload, len); res[len] = &#39;\0&#39;; Serial.println(res); } void setup(){ Serial.begin(9600); while(!Serial.available()); InitWiFi(); if (!client.isConnected()) reconnect(); int rc = client.subscribe(topicName, MQTT::QOS0, messageArrived); if (rc != 0) Serial.println(String("rc from MQTT subscribe is ")+rc); else Serial.println(String("rc from MQTT subscribe is ")+rc); } void loop(){ Serial.println("loop"); client.yield(100); delay(2000); } void InitWiFi(){ LWiFi.begin(); // Keep retrying until connected to AP Serial.println("Connecting to AP"); while (0 == LWiFi.connect(WIFI_AP, LWiFiLoginInfo(WIFI_AUTH, WIFI_PASSWORD))) { Serial.println("Retry connect AP ... "); delay(1000); } Serial.println("Connected to AP"); } void reconnect() { // Loop until we&#39;re reconnected if(!client.isConnected()) { int rc = ipstack.connect(servername, port); if (rc == 1){ Serial.println("IPStack Success"); }else{ Serial.println("IPStack Failed"); } Serial.print("Connecting to IOT platform ..."); MQTTPacket_connectData data = MQTTPacket_connectData_initializer; data.MQTTVersion = 4; data.clientID.cstring = clientName; data.username.cstring = userName; data.password.cstring = password; rc = client.connect(data); if (rc == 0) { Serial.println( "[DONE]" ); } else { Serial.println( "[FAILED]"); delay(5000); } } } ``` 我的问题是： 有没有大神使用LinkIT One基于paho的mqtt实现了客户端，可以正常pub/sub话题，测试的mqtt代理可以是mosquitto或IBM Watson或中移OneNet？允许修改paho或LWiFiClient的源码？（我只要基于paho的实现） 提示： 1.通过之前在Arduino UNO、BeagleBone Black、树莓派2的实验感觉各种mqtt的代理基本都一样的，能在mosquitto上测试通过的基本都能在IBM Watson或OneNet上测试通过； 2.LinkIt One用pubsub测试没有问题，这说明LWiFiClient很大概率是没问题的，估计要修改paho的实现代码

android MQTT apollo 连接问题_course

我正在做MQTT测试 已经测试N遍了 在J2SE上面跑就没问题 到android就直接挂在 new MqttClient 这块了。。。。 网络，网段 配置啥都没问题 有谁能帮忙解决一下 Exception: at org.eclipse.paho.client.mqttv3.persist.MqttDefaultFilePersistence.open(MqttDefaultFilePersistence.java:76)

Maven的pom.xml第一行报错，显示未知错误，哪位大佬能帮忙解决下，不胜感激！_course

问题rt 代码如下：   ``` <?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <!-- 从spring-boot-starter-parent继承版本号 --> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.5.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <groupId>com.manning</groupId> <artifactId>readinglist</artifactId> <version>0.0.1-SNAPSHOT</version> <name>Reading List</name> <description>Reading List Demo</description> <properties> <java.version>1.8</java.version> </properties> <!-- 起步依赖 --> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-jpa</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-thymeleaf</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>com.h2database</groupId> <artifactId>h2</artifactId> <scope>runtime</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> </dependencies> <!-- maven构建插件 --> <build> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project> ```

Mqtt 整合 spring mvc， 启动时候的时候可以链接，但是接收消息就失去链接_course

异常信息： 1. 启动的时候，控制台会打印出close， 这是outbond通道的类打印出来的 2. 我模拟product发送一条数据，tomcat控制台输出异常信息 ERROR inbound.MqttPahoMessageDrivenChannelAdapter - Lost connection:宸叉柇寮?繛鎺? retrying... ERROR inbound.MqttPahoMessageDrivenChannelAdapter - Lost connection:宸叉柇寮?繛鎺? retrying... 接收到信息ooo:close

如何检查我与mqtt代理的连接是否断开？_course

<div class="post-text" itemprop="text"> <p>我正在尝试使用<a href="https://github.com/eclipse/paho.mqtt.golang" rel="nofollow noreferrer">paho</a> pkg来通过golang构建MQTT子客户端，当代理断开连接时，我的客户端就会出现问题，我一开始以为会出现丢失的消息，但这种情况并没有发生，启动代理后，MQTT子客户端却无法获得由MQTT PUB客户端发送的消息。</p> <p>为什么会发生这种事，我怎么才能解决呢？</p> <p>代码：</p> <pre><code>package main import ( "fmt" "os" mqtt "github.com/eclipse/paho.mqtt.golang" ) var ( broker = "tcp://localhost:1883" f mqtt.MessageHandler = func(client mqtt.Client, msg mqtt.Message) { fmt.Printf("TOPIC: %s ", msg.Topic()) fmt.Printf("MSG: %s ", msg.Payload()) } ) func main() { //create a ClientOptions opts := mqtt.NewClientOptions().AddBroker(broker) opts.SetClientID("group-one") opts.SetDefaultPublishHandler(f) //create and start a client using the above ClientOptions c := mqtt.NewClient(opts) if token := c.Connect(); token.Wait() &amp;&amp; token.Error() != nil { panic(token.Error()) } if token := c.Subscribe("test", 0, nil); token.Wait() &amp;&amp; token.Error() != nil { fmt.Println(token.Error()) os.Exit(1) } for { } } </code></pre> </div>

mqtt使用线程开启多个服务器发布数据 并实现多个客户端的订阅_course

mqtt使用线程开启多个服务器发布数据 并实现多个客户端的订阅

MQTT发布的返回值int类型，怎么判断它是否发布成功_course

MQTT发布的返回值类型怎么判断，难道是大于一的就发布成功，小于1的就发布失败么。发布完之后，怎么拿到他的主题。是直接MQTT对象 点它的主题属性出来么？？ 还有的就是订阅的时候怎么显示订阅主题的内容出来尼

在附加依赖项里面已经添加了相应的lib文件，为什么编译链接的时候还是提示无法解析的外部符号？_course

错误 1 error LNK2019: 无法解析的外部符号 _D3DX11CompileFromFileW@44，该符号在函数 "protected: bool __thiscall D3Dclass::CompileD3DShder(wchar_t const *,char *,char *,struct ID3D10Blob * *)" (?CompileD3DShder@D3Dclass@@IAE_NPB_WPAD1PAPAUID3D10Blob@@@Z) 中被引用 E:\bianxiede\Win32Project13\Win32Project13\D3Dclass.obj Win32Project13  我上网上查了查D3DX11CompileFromFile需要d3dx11.lib，我已经添加了，为什么还是提示无法解析的外部符号？ #pragma comment ( lib, "D3DX11.lib") 用这个显式的添加也不行 求大神解答

MQTT TLS加密传输证书验证不过去。_course

嵌入式设备客户端： ./mosquitto_sub -h 172.22.50.2 -u sub_client -P 123456 -p 8883 -t hh --cafile ./ca.crt --tls-version tlsv1 linux服务器： mosquitto -c ./mosquitto.conf -v mosquitto.conf ``` pid_file /var/run/mosquitto.pid persistence true persistence_location /var/lib/mosquitto/ port 8883 cafile /etc/mosquitto/myca/ca.crt certfile /etc/mosquitto/myca/server.crt keyfile /etc/mosquitto/myca/server.key tls_version tlsv1 `` 服务器报错： ``` 1552620704: OpenSSL Error: error:1409441B:SSL routines:SSL3_READ_BYTES:tlsv1 alert decrypt error 1552620704: OpenSSL Error: error:140940E5:SSL routines:SSL3_READ_BYTES:ssl handshake failure ```

socket如何实现其中的发送回调函数和完成发送的代码功能_course

c#socket异步通信中的SendCallback类包含在静态类中如何实现其中的发送回调函数和完成发送的代码功能 以及错误如何解决图片说明](https://img-ask.csdn.net/upload/201509/16/1442378441_762401.jpg) using Newtonsoft.Json; using System; using System.Collections.Generic; using System.IO; using System.Linq; using System.Net; using System.Net.Sockets; using System.Text; using System.Threading.Tasks; using System.ComponentModel; using System.Data; using System.Windows.Forms; using System.Threading; namespace DAL { /// <summary> /// Socket接口 /// </summary> static class socket { //Socket public static Socket clientSocket; /// <summary> /// socket连接 /// </summary> /// <returns> /// true 成功 /// false 失败 /// </returns> public static bool SocketConnect() { byte[] receive_buff = new byte[256]; ManualResetEvent connectDone = new ManualResetEvent(false); //连接的信号 ManualResetEvent readDone = new ManualResetEvent(false); //读信号 ManualResetEvent sendDone = new ManualResetEvent(false); //发送结束 //从配置文件获取IP string SocketIP = DAL.Common.ReadConfigString("Recover", "IP"); //从配置文件获取端口 int SocketPort = Convert.ToInt32(DAL.Common.ReadConfigString("Recover", "Port")); //创建IP地址 IPAddress IP = IPAddress.Parse(SocketIP); try { //创建socket实例 clientSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp); //创建网络端点 IPEndPoint ipEnd = new IPEndPoint(IP, SocketPort); //EndPoint ipEnd = (EndPoint)remotepoint; //与目标终端连接 clientSocket.BeginConnect(ipEnd, new AsyncCallback(ConnectCallback), clientSocket);//调用回调函数 connectDone.WaitOne(); if (clientSocket.Connected) { return true; } else { return false; } } catch (Exception e) { string strError = ""; strError += "\r\n SocketIP = " + SocketIP.ToString(); strError += "\r\n SocketPort = " + SocketPort.ToString(); DAL.Common.WriteErrorLog(e, strError); return false; } } public static void ConnectCallback(IAsyncResult ar) { bool connect_flag = false; ManualResetEvent connectDone = new ManualResetEvent(false); //连接的信号 Socket client = (Socket)ar.AsyncState; client.EndConnect(ar); connect_flag = true; connectDone.Set(); } /// <summary> /// Socket发送数据 /// </summary> /// <param name="strSend"> /// 数据的内容 /// </param> public static void SocketSend(string strSend) { Socket tcpsend; //发送创建套接字 ManualResetEvent sendDone = new ManualResetEvent(false);//发送结束 int length = strSend.Length; Byte[] Bysend = new byte[length]; try { Bysend = System.Text.Encoding.Default.GetBytes(strSend); //将字符串指定到指定Byte数组 tcpsend.BeginSend(Bysend, 0, Bysend.Length, 0, new AsyncCallback(SendCallback), tcpsend); //异步发送数据 sendDone.WaitOne(); } catch (Exception e) { string strError = ""; DAL.Common.WriteErrorLog(e, strError); } } private void SendCallback(IAsyncResult ar) //发送的回调函数 { Socket client = (Socket)ar.AsyncState; int bytesSend = client.EndSend(ar); //完成发送 sendDone.Set(); }

golang mqtt发布并订阅_course

<div class="post-text" itemprop="text"> <p>Does anybody know where I can get some example MQTT client Go (golang) code that does both publish and subscribe in an infinite loop ?</p> <p>I am messaging with a Mosquitto broker running on MacOs.</p> <p>In more detail... </p> <ol> <li>Get a message from the network (a topic)</li> <li>Compute something based on that message</li> <li>Send the result of the computation back to the network (topic)</li> </ol> <p>Here is the code I am using:</p> <pre><code>package main import ( "fmt" MQTT "github.com/eclipse/paho.mqtt.golang" "os" "time" ) var knt int var f MQTT.MessageHandler = func(client MQTT.Client, msg MQTT.Message) { fmt.Printf("MSG: %s ", msg.Payload()) text:= fmt.Sprintf("this is result msg #%d!", knt) knt++ token := client.Publish("nn/result", 0, false, text) token.Wait() } func main() { knt = 0 opts := MQTT.NewClientOptions().AddBroker("tcp://localhost:1883") opts.SetClientID("mac-go") opts.SetDefaultPublishHandler(f) c := MQTT.NewClient(opts) if token := c.Connect(); token.Wait() &amp;&amp; token.Error() != nil { panic(token.Error()) } if token := c.Subscribe("nn/sensors", 0, nil); token.Wait() &amp;&amp; token.Error() != nil { fmt.Println(token.Error()) os.Exit(1) } time.Sleep(3 * time.Second) } //end of main </code></pre> <p>I looked through the GoDocs for some hint as to how to keep the connections open but nothing seems pertinent. I can certainly do an infinite loop over the &#39;subscribe&#39; but that seems inefficient. </p> </div>

请问如何实现c语言编写MQTT发送消息至EMQ？_course

（刚开始接触这个方面，什么经验都没有，希望大家帮帮忙，谢谢） 1.我已经安装好了VS2013； 2.我参考的网址是 ①https://blog.csdn.net/vincent_yuan89/article/details/84306001#commentBox ②https://blog.csdn.net/qingdujun/article/details/71055759 3.目前遇到的问题是不知道怎么安装（https://github.com/eclipse/paho.mqtt.c/tree/v1.3.0）上的paho c库，以及如何导入vs。 4.之后的步骤也不是很清楚，比如vs新建项目应该是什么种类？ 谢谢！

如何使用paho.mqtt.golang库订阅多个MQTT主题？_course

<div class="post-text" itemprop="text"> <p>I try to connect to a MQTT broker running on an external server where I need to handle multiple different topics. The problem is, that <strong>only the last subscribed handler is called</strong>, even if the topic does not match the one passed as parameter to the <code>Subscribe()</code> method.</p> <p><strong>Example:</strong> sending any content to <code>p1/test</code> triggers the registrationHandler which only should listen for "<em>P1/controller/registration</em>". The other handlers or the DefaultPublishHandler are never called.</p> <p>A simplified version of my program:</p> <pre><code>func main(){ var opts = MQTT.NewClientOptions() opts.AddBroker(address) opts.SetClientID("go-controller") opts.SetDefaultPublishHandler(func(client MQTT.Client, msg MQTT.Message) { log.Printf("topic: %s ", msg.Topic()) }) client = MQTT.NewClient(opts) if token := client.Connect(); token.Wait() &amp;&amp; token.Error() != nil { log.Panicln(token.Error()) } client.Subscribe("P1/#", 0, logHandler) client.Subscribe("P1/controller/registration", 0, registrationHandler) } var logHandler MQTT.MessageHandler = func(client MQTT.Client, msg MQTT.Message) { ... log.Printf("Topic %s logged... ", msg.Topic()) } var registrationHandler MQTT.MessageHandler = func(client MQTT.Client, msg MQTT.Message) { ... log.Printf("Topic %s registered... ", message.Value) } </code></pre> <p><strong>EDIT #1</strong></p> <p>I found out that the oder of subscribing to topics matters. When I swap both subscription calls the correct handlers get called.</p> </div>

求大神跟我解释一下这个程序_course

``` import paho.mqtt.client as mqtt from concurrent import futures clients=[] nclients=20 mqtt.Client.connected_flag=False #start False #create clients ######################################## for i in range(nclients): cname="Client"+str(i) client= mqtt.Client(cname) clients.append(client) ######################################## ex = futures.ThreadPoolExecutor(max_workers=10)#这个语句的意思是10个进程并发吗？ futures object 这个对象是干嘛的 while True: #main loop for i in range(len(clients)): client.loop(0.01) #if not connected then connect.Max connection attempts #at once is set by max_workers#既然并发，为什么还要在这里加loop循环 if not client.connected_flag:#flag set true in on_connect f = ex.submit(Connect,parameter1,parameter2,etc#这个submit是什么意思，后面的参数parameter应该填什么 ``` ``` #!/usr/bin/env python import sys import paho.mqtt.client as mqtt import serial import time from functools import reduce import threading port = "/dev/ttyACM1" broker_adress = "10.0.2.190" sys.path.append("/home/hu/Schreibtisch/Arduino_BA_2.0/Probe_Programmierung/Python-Arduino-Proto-API-v2/arduino") ser = serial.Serial(port, 9600,timeout= 1) gassensor_value = "default_value" voltagesensor_value = "default value" currentsensor_value = "default value" temperaturesensor_value_1 = "default_value" temperaturesensor_value_2 = "default_value" humidity_value = "default_value" air_pressure_value = "default_value" altitude_value = "default_value" sensor_value = [[&#39;/CBCU/CB123/inner_space_of_CB/gassensor&#39;,gassensor_value], [&#39;/CBCU/CB123/battery/voltagesensor&#39;, voltagesensor_value], [&#39;/CBCU/CB123/battery/currentsensor&#39;, currentsensor_value], [&#39;/CBCU/CB123/wassertank/temperature&#39;, temperaturesensor_value_1], [&#39;/CBCU/CB123/battery/humidity&#39;, humidity_value], [&#39;/CBCU/CB123/inner_space/temperature_of_inner_space&#39;, temperaturesensor_value_2], [&#39;/CBCU/CB123/inner_space/air_pressure&#39;, air_pressure_value], [&#39;/CBCU/CB123/inner_space/altitude&#39;, altitude_value]] def char2int(s): return {&#39;0&#39;:0,&#39;1&#39;:1,&#39;2&#39;:2,&#39;3&#39;:3,&#39;4&#39;:4,&#39;5&#39;:5,&#39;6&#39;:6,&#39;7&#39;:7,&#39;8&#39;:8,&#39;9&#39;:9}[s] def mulit_int(x,y): return 10*x+y def str2int(s): if s.find(&#39;.&#39;) == -1: # 不是浮点数 return reduce(mulit_int, map(char2int, s)) else: # 是浮点数 s1 = s.split(&#39;.&#39;) s2int = reduce(mulit_int, map(char2int, s1[0])) # 整数部分 s2float = reduce(mulit_int, map(char2int, s1[1])) * 0.1 ** len(s1[1]) # 小数部分 return s2int + s2float ######################################################################### # Callback_1 for relay #on_connect1,on_disconnect1,on_subscribe１on_message_1 ######################################################################### def on_connect1(mqttrelay, obj, flags, rc): if rc != 0: exit(rc) else: mqttrelay.subscribe("qos0/test", 0) def on_disconnect1(mqttrelay, obj, rc): obj = rc def on_subscribe1(mqttrelay, obj, mid, granted_qos): print(mqttrelay.subscribe("qos0/test", 0)) print("Waiting for the subscribed messages") def on_message1(mqttrelay,userdata, message): a = str(message.payload.decode("utf-8")) if (a == "131"): ser.write(b&#39;131&#39;) elif(a == "130"): ser.write(b&#39;130&#39;) # time.sleep(1) # else: # ser.write(b&#39;0&#39;) # time.sleep(1) # else: print("please publish the message 1 or 0") ######################################################################### #Callback_2 for gassensor #on_connect2,on_publish2 ######################################################################### def on_publish2(mqttsensor, obj, mid): print("mid: " + str(mid)) def on_connect2(mqttsensor, userdata, flags, rc): print("Connected with result code " + str(rc)) def on_publish3(mqttgassensor, obj, mid): print("mid: " + str(mid)) def on_connect3(mqttgassensor, userdata, flags, rc): print("Connected with result code " + str(rc)) #create new instance to subscribe the sitution of relay mqttrelay = mqtt.Client("relay_K_12", 1) #create new instance to publish the situation of sensor mqttsensor = mqtt.Client("sensor",1) #create new instance to publish the situation of gassensor mqttgassensor = mqtt.Client("gassensor",1) #the events and callbacks of instance mqttrelais associate with each other: mqttrelay.on_message = on_message1 mqttrelay.on_connect = on_connect1 mqttrelay.on_subscribe = on_subscribe1 mqttrelay.on_disconnect = on_disconnect1 mqttrelay.connect(broker_adress) #the events and callbacks of instance sensor associate with each other: mqttsensor.on_connect = on_connect2 mqttsensor.on_publish = on_publish2 mqttsensor.connect(broker_adress) #the events and callbacks of instance gassensor associate with each other: mqttgassensor.on_connect = on_connect3 mqttgassensor.on_publish = on_publish3 mqttgassensor.connect(broker_adress) def read_Sensor1(): i = 0 while True: temp = ser.readline().decode(&#39;ascii&#39;) #print(type(temp)) #print(temp) if temp.split(&#39;:&#39;)[0] == "Voltage": sensor_value[1][1] = temp i = i + 1 elif temp.split(&#39;:&#39;)[0] == "amperage": sensor_value[2][1] = temp i = i + 1 elif temp.split(&#39;:&#39;)[0] == "temperature1": sensor_value[3][1] =temp i = i + 1 elif temp.split(&#39;:&#39;)[0] == "RH": sensor_value[4][1] =temp i = i + 1 elif temp.split(&#39;:&#39;)[0] == "temperature2": sensor_value[5][1] =temp i = i + 1 elif temp.split(&#39;:&#39;)[0] =="airpressure": sensor_value[6][1] =temp i = i + 1 elif temp.split(&#39;:&#39;)[0] == "altitude": sensor_value[7][1] =temp i = i + 1 if (i == 7): break print(sensor_value[1]) mqttsensor.publish("/CBCU/CB123/battery/voltagesensor", sensor_value[1][1], retain=1) print(sensor_value[2]) mqttsensor.publish("/CBCU/CB123/battery/currentsensor", sensor_value[2][1], retain=1) print(sensor_value[3]) mqttsensor.publish("/CBCU/CB123/wassertank/temperature", sensor_value[3][1], retain=1) print(sensor_value[4]) mqttsensor.publish("/CBCU/CB123/battery/humidity", sensor_value[4][1], retain=1) print(sensor_value[5]) mqttsensor.publish("/CBCU/CB123/inner_space/temperature_of_inner_space", sensor_value[5][1], retain=1) print(sensor_value[6]) mqttsensor.publish("/CBCU/CB123/inner_space/air_pressure", sensor_value[6][1], retain=1) print(sensor_value[7]) mqttsensor.publish("/CBCU/CB123/inner_space/altitude", sensor_value[7][1], retain=1) def read_Sensor2(): j = 0 while True: temp = ser.readline().decode(&#39;ascii&#39;) # print(type(temp)) # print(temp) if temp.split(&#39;:&#39;)[0] == "Gassesnsor": sensor_value[0][1] = temp j = j + 1 if (j == 1): break print(sensor_value[0]) mqttsensor.publish("/CBCU/CB123/inner_space_of_CB/gassensor", sensor_value[0][1],retain = 1) def loop1(): while True: time.sleep(10) #mqttrelay.loop() mqttsensor.loop() read_Sensor1() time.sleep(10) def loop2(): while True: read_Sensor2() mqttgassensor.loop() def main(): added_thread1 = threading.Thread(target=loop1,name = "thread_1") added_thread2 = threading.Thread(target=loop2,name = "thread_2") added_thread2.start() added_thread1.start() main() ``` 上面是我的程序，求大佬給個點子，自己用多線程試了很多次，就是出錯 Exception in thread thread_1: Traceback (most recent call last): File "/home/hu/PycharmProjects/mqtt_probe/venv/lib/python3.5/site-packages/serial/serialposix.py", line 501, in read &#39;device reports readiness to read but returned no data &#39; serial.serialutil.SerialException: device reports readiness to read but returned no data (device disconnected or multiple access on port?) During handling of the above exception, another exception occurred: Traceback (most recent call last): File "/usr/lib/python3.5/threading.py", line 914, in _bootstrap_inner self.run() File "/usr/lib/python3.5/threading.py", line 862, in run self._target(*self._args, **self._kwargs) File "/home/hu/mqtt/8_publish_subscribe_for_sensoren_threads.py", line 208, in loop1 read_Sensor1() File "/home/hu/mqtt/8_publish_subscribe_for_sensoren_threads.py", line 126, in read_Sensor1 temp = ser.readline().decode(&#39;ascii&#39;) File "/home/hu/PycharmProjects/mqtt_probe/venv/lib/python3.5/site-packages/serial/serialposix.py", line 509, in read raise SerialException(&#39;read failed: {}&#39;.format(e)) serial.serialutil.SerialException: read failed: device reports readiness to read but returned no data (device disconnected or multiple access on port?) 求大佬們指正

MQTT.fx1.7.1连接服务器端时候connection lost_course

1.服务器是实体机，防火墙已关 2.在外部用ping和telnet都通了 3.MQTTfx能够连接其他服务器 4.该服务器从来没有连接成功过 5.log如下 2020-10-20 10:06:19,564 INFO --- BrokerConnectorController : onConnect 2020-10-20 10:06:19,565 INFO --- ScriptsController : Clear console. 2020-10-20 10:06:19,567 INFO --- MqttFX ClientModel : MqttClient with ID e997203411c94393a97d31062992b22c assigned. 2020-10-20 10:06:37,714 ERROR --- MqttFX ClientModel : Error when connecting org.eclipse.paho.client.mqttv3.MqttException: Connection lost at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:181) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_181] at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_181] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(Unknown Source) ~[?:1.8.0_181] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) ~[?:1.8.0_181] at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_181] at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_181] at java.lang.Thread.run(Unknown Source) [?:1.8.0_181] Caused by: java.net.SocketException: Connection reset at java.net.SocketInputStream.read(Unknown Source) ~[?:1.8.0_181] at java.net.SocketInputStream.read(Unknown Source) ~[?:1.8.0_181] at java.net.SocketInputStream.read(Unknown Source) ~[?:1.8.0_181] at java.io.DataInputStream.readByte(Unknown Source) ~[?:1.8.0_181] at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:92) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:133) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] ... 7 more 2020-10-20 10:06:37,717 ERROR --- MqttFX ClientModel : Please verify your Settings (e.g. Broker Address, Broker Port & Client ID) and the user credentials! org.eclipse.paho.client.mqttv3.MqttException: Connection lost at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:181) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) ~[?:1.8.0_181] at java.util.concurrent.FutureTask.run(Unknown Source) ~[?:1.8.0_181] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$201(Unknown Source) ~[?:1.8.0_181] at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(Unknown Source) ~[?:1.8.0_181] at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [?:1.8.0_181] at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [?:1.8.0_181] at java.lang.Thread.run(Unknown Source) [?:1.8.0_181] Caused by: java.net.SocketException: Connection reset at java.net.SocketInputStream.read(Unknown Source) ~[?:1.8.0_181] at java.net.SocketInputStream.read(Unknown Source) ~[?:1.8.0_181] at java.net.SocketInputStream.read(Unknown Source) ~[?:1.8.0_181] at java.io.DataInputStream.readByte(Unknown Source) ~[?:1.8.0_181] at org.eclipse.paho.client.mqttv3.internal.wire.MqttInputStream.readMqttWireMessage(MqttInputStream.java:92) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] at org.eclipse.paho.client.mqttv3.internal.CommsReceiver.run(CommsReceiver.java:133) ~[org.eclipse.paho.client.mqttv3-1.2.0.jar:?] ... 7 more 2020-10-20 10:06:37,720 INFO --- ScriptsController : Clear console. 2020-10-20 10:06:37,721 ERROR --- BrokerConnectService : Connection lost