Java Bean Company Imports Coffee Beans and Sells Them Under

Java Bean Company imports coffee beans and sells them under two-year contracts to Mellow Roast,Inc.,and other coffeemakers.The contracts require that during the two-year term a coffeemaker not buy beans from Java Bean's competitors.The contracts do not limit the coffeemakers' purchase of tea or other beverage ingredients from other suppliers,how?ever.In the second year of the contract,Mellow Roast protests that this arrangement violates antitrust law.Is Mellow Roast correct? If not,why not? If so,under which antitrust statute,or statutes,could these con?tracts be held illegal?