OAuth cannot authorize client using access_token

I am playing with OAuth in HCP. I am able to get "access_token" from HCP built-in token provider.

But when I submit my request to my servlet like:

Get  https://i062453appi062453trial.hanatrial.ondemand.com/b/c

http header:  Authorization: Bearer <mytoken>

Using firefox plugin RESTClient , I always get "not authorized".

I tried both oAuth servletfilter and using API, seems my webapp does not understand my token.

Is  my  GET request correct? Is there anything that I need pay attention.

Thanks,

Guoping