how to consume oData service?

Am using Maven Architechture for UI5. when i try to consume odata services its throwing an error 401 unauthorized.its getting loaded when am using the normal ui architechture. i tried giving the user name and password directly while loading the services. <--new sap.ui.model.odata.ODataModel("url", true,"username","password") -->. suggest me some methods to consume odata service.