AWS IoT Android application over MQTT throws MqttException (0) - java.io.IOException: Already connected

Question

I am trying to use \'Authenticate using Cognito-Identity with Cognito user pool\' in my Android application. My Cognito user pool authentication works well, when I run that

Answer 1

I beat my head up with this almost a week.

Full course of action -> After succesfull login you will have a jwt token

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

put it into a map

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

then use it to set in two places (not stated in any documentation!)

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

and

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);

after that you still nedd to make some call

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);

and only after that you can enable connect button and continue like that

mqttManager.connect(credentialsProvider, new AWSIotMqttClientStatusCallback() {

Really for this small piece of code i spent a lot of time...