Jasper Report remove login credentials from URL

Hi,

   I am calling report service using rest api like http://localhost:8080/jasperserver/rest_v2/reports/reports/samples/testN... . how can i avoid j_username=jasperadmin&j_password=jasperadmin  so that i dont want user to prompt to sign-in. How can i do this? Please show me some sample code that can pass sessionID in the url/headers so that it wont prompt for creadentials and will directly show the reports.

Thanks in advance,

Nithin