I was trying to connect to quickbooks online from google app engine by just running this simple code:
OAuthCredentials oauthcredentials = new OAuthCredentials(co
I am SO thankful that you posted this question. I had been banging my head against the wall for days with the same problem, except I am developing my Google App in the Go language, not Java. BUT I MADE IT WORK! I hope that my solution will help you also. Basically, instead of using the sockets service, I am using the URL Fetch service, documented for Java here: https://developers.google.com/appengine/docs/java/urlfetch/
I am pretty clueless about some of the details in your original post (I have not developed in Java, and am not familiar with the QBServiceFactory nor the OAuthCredentials). So I am not sure how much control you have over how it actually sends the requests to QB. But worst case scenario, I think you may be able to write your own functions to replace the QBServiceFactory (which I have had to do in Go), and if you make sure they use the URL Fetch service instead of sockets, you may have better luck.
As I said, I am very thankful for your question, because I do not think that I would have stumbled across my answer otherwise, so thank you!