Solution of facebook session key problem

I created an application named "HelloWorld" in facebook. And then use Java Facebook API to do something by calling "HelloWorld", the codes like:

1.  FacebookJsonRestClient facebook = new FacebookJsonRestClient(apiKey, secretKey);
3.  String  token = facebook.auth_createToken();
5.   ...... //login by user email and pwd
6.  String fbSession = facebook.auth_getSession(token);
8.   .......
10.  long userId=facebook.users_getLoggedInUser();
12.   .....

When I use another account (not the account who create "helloworld" app) to execute aboved codes, following exception popups (when calling the method "facebook.users_getLoggedInUser();"):

FacebookException: A session key is required for calling this method

 

The reason is session issue, the user who want to use "helloworld" app must allow the app to get profile and create an infinition session.

 

The Solution is:

Step 1: In web browser, log in facebook by using the user account who want to use my "helloworld" app

Step 2: In the same web browser, input the url: http://www.facebook.com/code_gen.php?v=1.0&api_key=HELLOWORLD_API_KEY

Step 3: follow the wizard page to create infinition session.