How do I look up a cognito user by their sub/UUID?

Question

I want to look up a user in my Cognito user pool by their sub, which as far as I can tell, is just their UUID. I would like to do this in Java within a Lambda function but c

Answer 1

     // class var
     protected final AWSCognitoIdentityProviderClient identityUserPoolProviderClient;

    // initialize the Cognito Provider client.  This is used to talk to the user pool
    identityUserPoolProviderClient = new AWSCognitoIdentityProviderClient(new BasicAWSCredentials(AWS_ACCESS_KEY, AWS_SECRET_KEY)); 
    identityUserPoolProviderClient.setRegion(RegionUtils.getRegion(USER_POOL_REGION)); 


    // ...some init code omitted        

// build the request
AdminGetUserRequest idRequest = new AdminGetUserRequest();
idRequest.withUserPoolId(USER_POOL_ID);
idRequest.withUsername(username);

// call cognito for the result
AdminGetUserResult result = identityUserPoolProviderClient.adminGetUser(idRequest);
// loop through results 

List userTypeList = result.getUsers();
// loop through them
for (UserType userType : userTypeList) {
    List attributeList = userType.getAttributes();
    for (AttributeType attribute : attributeList) {
        String attName = attribute.getName();
        String attValue = attribute.getValue();
        System.out.println(attName + ": " + attValue);
    }
}