通过MQTT的AWS IoT Android应用程序抛出MqttException（0） - java.io.IOException：已经连接

时间：2017-05-29 14:01:39

标签： android mqtt iot amazon-cognito aws-iot

我正在尝试使用Cognito-Identity和Cognito用户池进行身份验证＆＃39;在我的Android应用程序中。我的Cognito用户池身份验证运行良好，当我单独运行它时，我也看到了JWTToken。当我运行＆＃39; PubSub＆＃39;具有Unauthenticated角色的示例应用程序，它按预期工作。当我将这两个功能集成到一个应用程序中时，应用程序抛出了以下错误。

W/System.err: MqttException (0) - java.io.IOException: Already connected
W/System.err:     at org.eclipse.paho.client.mqttv3.internal.ExceptionHelper.createMqttException(ExceptionHelper.java:38)
W/System.err:     at org.eclipse.paho.client.mqttv3.internal.ClientComms$ConnectBG.run(ClientComms.java:664)
W/System.err:     at java.lang.Thread.run(Thread.java:761)
W/System.err: Caused by: java.io.IOException: Already connected
W/System.err:     at java.io.PipedOutputStream.connect(PipedOutputStream.java:100)
W/System.err:     at java.io.PipedInputStream.connect(PipedInputStream.java:195)
W/System.err:     at org.eclipse.paho.client.mqttv3.internal.websocket.WebSocketReceiver.<init>(WebSocketReceiver.java:42)
W/System.err:     at org.eclipse.paho.client.mqttv3.internal.websocket.WebSocketSecureNetworkModule.start(WebSocketSecureNetworkModule.java:78)
W/System.err:     at org.eclipse.paho.client.mqttv3.internal.ClientComms$ConnectBG.run(ClientComms.java:650)
W/System.err:   ... 1 more

自上周四以来，我一直试图解决这个问题，但仍然停留在同一个地方。真的不知道我应该在哪里检查。！

我正在添加我的身份验证（Cognito用户池身份验证）活动和Connect活动。

AmazonCognitoIdentityProviderClient identityProviderClient = new 
AmazonCognitoIdentityProviderClient(new AnonymousAWSCredentials(), new ClientConfiguration());
identityProviderClient.setRegion(Region.getRegion(Regions.US_WEST_2));
CognitoUserPool userPool = new CognitoUserPool(getApplicationContext(), "us-west-2_ghtcc6ho9", "4t0mk45hNso69dp2j4jvel5ghm", "1jmq0lhhq721oif9k6nug31c29i760vihua8hvrgu5umfr2a1vd7", identityProviderClient);
cogUser = userPool.getUser();
authenticationHandler = new AuthenticationHandler() {



        @Override
        public void onSuccess(CognitoUserSession userSession, CognitoDevice newDevice) {
            String ids = userSession.getIdToken().getJWTToken();
            Log.d("MyToken","session id___"+userSession.getIdToken().getExpiration()+"___"+userSession.getIdToken().getIssuedAt());
            Intent pubSub = new Intent(MainActivity.this, PubSubActivity.class);
            pubSub.putExtra("token",""+ids);
            startActivity(pubSub);
            //MainActivity.this.finish();

        }

        @Override
        public void getAuthenticationDetails(AuthenticationContinuation authenticationContinuation, String userId) {
            Log.d("MyToken","getAuthenticationDetails");
            AuthenticationDetails authenticationDetails = new AuthenticationDetails("shone", "172737", null);
            authenticationContinuation.setAuthenticationDetails(authenticationDetails);
            // Allow the sign-in to continue
            authenticationContinuation.continueTask();
        }

        @Override
        public void getMFACode(MultiFactorAuthenticationContinuation multiFactorAuthenticationContinuation) {
            Log.d("MyToken","getMFACode");
            multiFactorAuthenticationContinuation.continueTask();
        }

        @Override
        public void authenticationChallenge(ChallengeContinuation continuation) {
            Log.d("MyToken","authenticationChallenge"+continuation.getChallengeName());
            newPasswordContinuation.continueTask();
        }

        @Override
        public void onFailure(Exception exception) {
            exception.printStackTrace();
            Log.d("MyToken","onFailure");
        }
    };
     cogUser.getSessionInBackground(authenticationHandler);

当它到达OnSuccess＆＃39;我正在启动我的连接活动并将我的会话令牌与Intent一起传递。转到下一个活动

private static final String COGNITO_POOL_ID = "us-west-2:a153a090-508c-44c0-a9dd-efd450298c4b";
private static final Regions MY_REGION = Regions.US_WEST_2;
AWSIotMqttManager mqttManager;
String clientId;
AWSCredentials awsCredentials;
CognitoCachingCredentialsProvider credentialsProvider;
 @Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Intent intent = getIntent();
if(null == intent){
    Toast.makeText(getApplicationContext(), "Token is null", Toast.LENGTH_SHORT).show();
}else {
    token = intent.getStringExtra("token");
}
 clientId = UUID.randomUUID().toString();
    credentialsProvider = new CognitoCachingCredentialsProvider(
            getApplicationContext(), 
            COGNITO_POOL_ID, 
            MY_REGION 
    );
mqttManager = new AWSIotMqttManager(clientId, CUSTOMER_SPECIFIC_ENDPOINT);
 Map loginsMap = new HashMap();
    loginsMap.put("cognito-idp.us-west-2.amazonaws.com/us-west-2_ghtcc6ho9", token);
    credentialsProvider.setLogins(loginsMap);
    Log.d("SESSION_ID", ""+token);
    new Thread(new Runnable() {
        @Override
        public void run() {
            credentialsProvider.refresh();
            awsCredentials = credentialsProvider.getCredentials();
            Log.d("SESSION_ID B: ", ""+awsCredentials.getAWSAccessKeyId());
            Log.d("SESSION_ID C: ", ""+awsCredentials.getAWSSecretKey());
        }
    }).start();
}

 View.OnClickListener connectClick = new View.OnClickListener() {
    @Override
    public void onClick(View v) {

        Log.d(LOG_TAG, "clientId = " + clientId);

        try {
            mqttManager.connect(credentialsProvider, new AWSIotMqttClientStatusCallback() {
                @Override
                public void onStatusChanged(final AWSIotMqttClientStatus status,
                        final Throwable throwable) {
                    Log.d(LOG_TAG, "Status = " + String.valueOf(status)+"______"+((null !=throwable)?throwable.getMessage():""));

                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            if (status == AWSIotMqttClientStatus.Connecting) {
                                tvStatus.setText("Connecting...");

                            } else if (status == AWSIotMqttClientStatus.Connected) {
                                tvStatus.setText("Connected");

                            } else if (status == AWSIotMqttClientStatus.Reconnecting) {
                                if (throwable != null) {
                                    Log.e(LOG_TAG, "Connection error.", throwable);
                                }
                                tvStatus.setText("Reconnecting");
                            } else if (status == AWSIotMqttClientStatus.ConnectionLost) {
                                if (throwable != null) {
                                    Log.e(LOG_TAG, "Connection error.", throwable);
                                    throwable.printStackTrace();
                                }
                                tvStatus.setText("Disconnected");
                            } else {
                                tvStatus.setText("Disconnected");

                            }
                        }
                    });
                }
            });
        } catch (final Exception e) {
            Log.e(LOG_TAG, "Connection error.", e);
        }
    }
};

我的代码有什么问题？为什么在调用MQTT连接时抛出异常？任何帮助，将不胜感激。

3 个答案:

答案 0 :(得分：2)

我差不多一个星期就抬起头来。

完整的行动方针 - ＆gt; 成功登录后，您将拥有一个jwt令牌

String idToken = cognitoUserSession.getIdToken().getJWTToken();

将其放入地图

Map<String, String> logins = new HashMap<String, String>(); 
//fill it with Cognito User token
logins.put("cognito-idp.<REGION>.amazonaws.com/<COGNITO_USER_POOL_ID>", idToken);

然后用它来设置两个地方（未在任何文档中说明！）

CognitoCachingCredentialsProvider credentialsProvider = new 
CognitoCachingCredentialsProvider(context, IDENTITY_POOL_ID, REGION);
credentialsProvider.setLogins(logins);

和

AmazonCognitoIdentity cognitoIdentity = new AmazonCognitoIdentityClient(credentialsProvider);
GetIdRequest getIdReq = new GetIdRequest();
getIdReq.setLogins(logins); //or if you have already set provider logins just use credentialsProvider.getLogins()
getIdReq.setIdentityPoolId(COGNITO_POOL_ID);
GetIdResult getIdRes = cognitoIdentity.getId(getIdReq);
之后你仍然需要打电话

AttachPrincipalPolicyRequest attachPolicyReq = new AttachPrincipalPolicyRequest(); //in docs it called AttachPolicyRequest but it`s wrong
attachPolicyReq.setPolicyName("allAllowed"); //name of your IOTAWS policy
attachPolicyReq.setPrincipal(getIdRes.getIdentityId());
new AWSIotClient(credentialsProvider).attachPrincipalPolicy(attachPolicyReq);

然后才能启用连接按钮并按照

继续 
mqttManager.connect(credentialsProvider, new AWSIotMqttClientStatusCallback() {

真的对于这段小代码，我花了很多时间......

答案 1 :(得分：0)

当客户端连接到代理时，它具有唯一的客户端ID。如果客户端尝试使用相同的客户端ID连接，则会发生此错误。使用不同的客户端ID，如foo1，foo2，foo3等。

答案 2 :(得分：0)

我也遇到了同样的错误-

Feb 27, 2019 10:23:09 AM com.amazonaws.services.iot.client.mqtt.AwsIotMqttConnectionListener onFailure
WARNING: Connect request failure
MqttException (0) - java.io.IOException: Already connected
    at org.eclipse.paho.client.mqttv3.internal.ExceptionHelper.createMqttException(ExceptionHelper.java:38)
    at org.eclipse.paho.client.mqttv3.internal.ClientComms$ConnectBG.run(ClientComms.java:664)
    at java.lang.Thread.run(Thread.java:748)
Caused by: java.io.IOException: Already connected
    at java.io.PipedOutputStream.connect(PipedOutputStream.java:100)

但是问题不同。

首先，您不需要从代码中调用attachPrincipalPolicy。您也可以使用命令行。您可以执行类似-

aws iot attach-principal-policy --principal us-east-1:1c973d17-98e6-4df6-86bf-d5cedc1fbc0d --policy-name "thingpolicy" --region us-east-1 --profile osfg

您将从身份池的身份浏览器中获取主体ID。现在让我们来看看错误-

要使用经过身份验证的Cognito凭据成功连接到mqtt，您需要2条正确的策略-

  1. 与您的身份池相对应的经过身份验证的角色应允许所有mqtt操作。
  2. AWS IoT策略应允许相同的操作，并且您需要将您的认知身份与此策略相关联。我们使用attachPrincipalPolicy来这样做。

如果错过了任何步骤，我们将得到以上错误。我同意该错误具有误导性-Already connected对我而言毫无意义。我通常认为这与clientId有关，后者应该是唯一的。但是无论如何，希望AWS员工会在某个时候做得更好。

对于我的特殊情况，问题是第1点。尽管我的IoT策略具有所有必需的权限，但与身份池相对应的auth角色却没有。因此，请确保您这样做。

我也创建了一个youtube视频来展示此视频：https://www.youtube.com/watch?v=j2KJVHGHaFc

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