we can use the username & password flow that's part of the oauth2 support.
Hi all, I have arrived the solution to my problem. Actually, I was examining the sample given in the link http://wiki.developerforce.com/page/Getting_Started_with_the_Force.com_REST_API . Then implemented OAuth 2.0 Username-Password Flow which is from https://login.salesforce.com/help/doc/en/remoteaccess_oauth_username_password_flow.htm#send_up_response. It solves my problem.
http://www.salesforce.com/us/developer/docs/api_streaming/Content/code_sample_auth_oauth.htm
https://emea.salesforce.com/help/doc/en/remoteaccess_revoke_token.htm
https://emea.salesforce.com/help/doc/en/remoteaccess_authenticate.htm
https://login.salesforce.com/help/doc/en/remoteaccess_oauth_username_password_flow.htm#send_up_response
http://wiki.developerforce.com/page/Digging_Deeper_into_OAuth_2.0_at_Salesforce.com