<a href="<你的返回流的Action路径>" >下载</a>

<script type="text/javascript">

        function download(filename) {

            var oReq = new XMLHttpRequest();

            oReq.open("GET", "<你的返回流的Action路径>", true);

            oReq.responseType = "blob";

            oReq.onload = function (oEvent) {

                var content = oReq.response;

                var elink = document.createElement('a');

                elink.download = filename;

                elink.style.display = 'none';

                var blob = new Blob([content]);

                elink.href = URL.createObjectURL(blob);

                document.body.appendChild(elink);

                elink.click();

                document.body.removeChild(elink);

            };

            oReq.send();

        }

    </script>