java - AWSIotMqttManager：onFailure：连接失败。MqttException (0) - java.io.IOException: 已经连接

Question

我目前正在使用 Android Studio 开发一个移动应用程序，该应用程序应该通过 AWS Cognito 进行身份验证，我使用 AWS Amplify 进行验证。Amplify 似乎工作正常，但是当我尝试连接到我的 Greengrass 事物的设备影子时，我从这个问题的标题中得到了错误：

AWSIotMqttManager：onFailure：连接失败。MqttException (0) - java.io.IOException: 已经连接

这很奇怪，因为我还没有调用连接命令，所以我不应该连接。

这是我的代码：

// Here I get the credentials which I later use to connect to AWSIoT    
CognitoCachingCredentialsProvider credentialsProvider = new CognitoCachingCredentialsProvider(
                getApplicationContext(), // get the context for the current activity
                "*****", // your AWS Account id
                "us-east-2:****************", // your identity pool id
                "arn:aws:iam::*************-unauthRole",// an authenticated role ARN
                "arn:aws:iam::*************-authRole", // an unauthenticated role ARN
                Regions.US_EAST_2 //Region
        );
    


        //Here I create the AWSIotMqttManager
        AWSIotMqttManager awsIotMqttManager = new AWSIotMqttManager(uuidAsString,"endpoint");
       
       //then I connect it
       try {
            awsIotMqttManager.connect(credentialsProvider, new AWSIotMqttClientStatusCallback() {
                @Override
                public void onStatusChanged(AWSIotMqttClientStatus status, Throwable throwable) {

                    if (status == AWSIotMqttClientStatus.Connected) {

                        awsIotMqttManager.subscribeToTopic("$aws/things/thing/shadow/update/documents", AWSIotMqttQos.QOS0, new AWSIotMqttNewMessageCallback() {
                            @Override
                            public void onMessageArrived(String topic, byte[] data) {
                                System.out.println("TOPIC: " + topic);
                                System.out.println(data);
                            }
                        });

                        String message = "{ \"state\": {\"desired\": {\"message\": \"Hello from ANDROID SDK\"} } }} }";
                        awsIotMqttManager.publishString(message,"$aws/things/thing/shadow/update",AWSIotMqttQos.QOS0);

                    }
                    
             
            });
        }
        catch (Exception e) {
            Log.i("CHECK", e.toString());
        }

标签： javaamazon-web-servicesamazon-cognitoaws-iotaws-iot-greengrass