Does WSO2 ESB (4.5.0) Oauth Mediator support OAuth2.0 Bearer token?

问题

I got an "Error while validating OAuth2 request" message when I send a OAuth2.0 Bearer token to WSO2 ESB (4.5.0) Oauth Mediator.

Does WSO2 ESB (4.5.0) Oauth Mediator support OAuth2.0 Bearer token ? What's the correct request for Oauth Mediator?

My bearer header...

conn = (HttpURLConnection)url.openConnection();
conn.setRequestProperty("Authorization", "bearer " + request.getParameter("accessToken").toString() );      
conn.setRequestProperty("Content-Type","application/x-www-form-urlencoded"); 

来源：https://stackoverflow.com/questions/13485069/does-wso2-esb-4-5-0-oauth-mediator-support-oauth2-0-bearer-token