在 Android 中订阅 IOT 主题答案

【问题标题】：Subscribing to IOT topic in Android在 Android 中订阅 IOT 主题
【发布时间】：2019-05-09 11:01:20
【问题描述】：

我正在尝试通过我的 Android 应用程序订阅一个主题。即使它连接成功订阅失败。一旦我执行订阅呼叫，IOT 连接就会失败并给出如下所述的错误日志。想知道我在哪里做错了编码？ IOT政策的所有资源都是出于测试目的，以寻找线索。

{
  "Version": "2012-10-17",
  "Statement": [
   {
      "Effect": "Allow",
      "Action": "iot:*",
      "Resource": "*"
   }
 ]
}

我为我的开发推荐了 AWS-amplify。 https://aws-amplify.github.io/docs/android/pubsub

1.连接物联网

    private var mAWSMobileClient : AWSMobileClient = AWSMobileClient.getInstance()
    private lateinit var mIotDataManager: AWSIotMqttManager
    private lateinit var mAttachedPolicyReq: AttachPolicyRequest
    private lateinit var mAwsIOTClient: AWSIotClient
    private lateinit var mAwsCredentials: AWSCredentials

 private fun connectToIOT() {
        Thread(Runnable {
            var mDeviceIdentity = Settings.Secure.getString(this.contentResolver, Settings.Secure.ANDROID_ID)

            mIotDataManager = AWSIotMqttManager(mDeviceIdentity, <iot endpoint>)
            mIotDataManager.keepAlive = 50
            mIotDataManager.isAutoReconnect = false
            mIotDataManager.connectionStabilityTime = 100

            mAwsCredentials = mAWSMobileClient.awsCredentials
            mAwsIOTClient = AWSIotClient(mAWSMobileClient)
            mAwsIOTClient.setRegion(Region.getRegion(Regions.AP_SOUTHEAST_2))

            mAttachedPolicyReq = AttachPolicyRequest()
            mAttachedPolicyReq.policyName = "test_policy"
            mAttachedPolicyReq.target = mAWSMobileClient.identityId
            mAwsIOTClient.attachPolicy(mAttachedPolicyReq)

            try {
                mIotDataManager.connect(mAWSMobileClient, object : AWSIotMqttClientStatusCallback {
                    override fun onStatusChanged(
                        status: AWSIotMqttClientStatusCallback.AWSIotMqttClientStatus?,
                        throwable: Throwable?
                    ) {
                        when (status) {
                            AWSIotMqttClientStatusCallback.AWSIotMqttClientStatus.ConnectionLost -> {}

                            AWSIotMqttClientStatusCallback.AWSIotMqttClientStatus.Connected -> {}

                            AWSIotMqttClientStatusCallback.AWSIotMqttClientStatus.Connecting -> {}

                            AWSIotMqttClientStatusCallback.AWSIotMqttClientStatus.Reconnecting -> {}

                        else -> {

                        }
                    }
                }
            })
        } catch (e: Exception) {
            Log.d("IOT Data Manager Connection Errror : $e")
        }
    }).start()
}

订阅方式

fun subscribeToThing() {
        if(mConnected) {
            Thread(Runnable {
                mThingsName = "$mThingsName/shadow/get/accepted"
                var message: String? = null
                try {
                    mIotDataManager.subscribeToTopic(
                        mThingsName,
                        AWSIotMqttQos.QOS1,
                        object : AWSIotMqttNewMessageCallback {
                            override fun onMessageArrived(topic: String?, data: ByteArray?) {

                                try {
                                    message = String(data!!, Charsets.UTF_8)
                                } catch (e: UnsupportedEncodingException) {
                                    Log.d("Unsupported Encoding error :$e")
                                }
                            }
                        })
                } catch (e: Exception) {
                    Log.d("Subscription error :$e")
                }
        }).start()
    } else {
        Log.d("IOT Not Connected")
        }
}

结果日志：

W/AWSIotMqttManager：连接丢失

订阅错误：com.amazonaws.AmazonClientException：客户端错误订阅时。

【问题讨论】：

标签： android amazon-web-services iot

【解决方案1】：

我看到您使用的是AWSMobileClient。也许您在使用 IOT 客户端之前没有初始化移动客户端实例？以下documentation 中概述了详细信息。

【讨论】：