HTML5可以下載的，不需要後端，純前端支援。HTML5的一個例子：

var content = "file content!";
var data = new Blob([content],{type:"text/plain;charset=UTF-8"});
var downloadUrl = window.URL.createObjectURL(data);
var anchor = document.createElement("a");
anchor.href = downloadUrl;
anchor.download = "檔名.txt";
anchor.click();
window.URL.revokeObjectURL(data); 
 

                            //檔案下載
                            var blob = new Blob([要儲存的檔案流], { type: 'application/octet-stream' }),
                                fileName = 'filename' + path.substring(path.lastIndexOf("."), path.length);
                            ////filename，摘取了常用的部分，其實還有其他一些mimetypes = array(
                            ////    'doc'        => 'application/msword',
                            ////    'bin'        => 'application/octet-stream',
                            ////    'exe'        => 'application/octet-stream',
                            ////    'so'        => 'application/octet-stream',
                            ////    'dll'        => 'application/octet-stream',
                            ////    'pdf'        => 'application/pdf',
                            ////    'ai'        => 'application/postscript',
                            ////    'xls'        => 'application/vnd.ms-excel',
                            ////    'ppt'        => 'application/vnd.ms-powerpoint',
                            ////    'dir'        => 'application/x-director',
                            ////    'js'        => 'application/x-javascript',
                            ////    'swf'        => 'application/x-shockwave-flash',
                            ////    'xhtml'        => 'application/xhtml+xml',
                            ////    'xht'        => 'application/xhtml+xml',
                            ////    'zip'        => 'application/zip',
                            ////    'mid'        => 'audio/midi',
                            ////    'midi'        => 'audio/midi',
                            ////    'mp3'        => 'audio/mpeg',
                            ////    'rm'        => 'audio/x-pn-realaudio',
                            ////    'rpm'        => 'audio/x-pn-realaudio-plugin',
                            ////    'wav'        => 'audio/x-wav',
                            ////    'bmp'        => 'image/bmp',
                            ////    'gif'        => 'image/gif',
                            ////    'jpeg'        => 'image/jpeg',
                            ////    'jpg'        => 'image/jpeg',
                            ////    'png'        => 'image/png',
                            ////    'css'        => 'text/css',
                            ////    'html'        => 'text/html',
                            ////    'htm'        => 'text/html',
                            ////    'txt'        => 'text/plain',
                            ////    'xsl'        => 'text/xml',
                            ////    'xml'        => 'text/xml',
                            ////    'mpeg'        => 'video/mpeg',
                            ////    'mpg'        => 'video/mpeg',
                            ////    'avi'        => 'video/x-msvideo',
                            ////    'movie'        => 'video/x-sgi-movie',
                            ////);
                            downFile(blob, fileName);
 

  //js下載檔案流
    function downFile(blob, fileName) {
        if (window.navigator.msSaveOrOpenBlob) {
            navigator.msSaveBlob(blob, fileName);
        } else {
            var link = document.createElement('a');
            link.href = window.URL.createObjectURL(blob);
            link.download = fileName;
            link.click();
            window.URL.revokeObjectURL(link.href);
        }
    }
 

因為只是簡單html頁面，沒有後臺程式碼。想通過jquery的函式將返回的json資料內的一個二進位制陣列儲存為檔案。

HTML5可以下載的，不需要後端，純前端支援。HTML5的一個例子：

var content = "file content!";
var data = new Blob([content],{type:"text/plain;charset=UTF-8"});
var downloadUrl = window.URL.createObjectURL(data);
var anchor = document.createElement("a");
anchor.href = downloadUrl;
anchor.download = "檔名.txt";
anchor.click();
window.URL.revokeObjectURL(data); 

通過json獲得的二進位制，應該不是實際意義上的二進位制吧？
json中的陣列不是TypedArray，需要轉化一下。

var binaryData = [0,0,1,1,1,0,0,0,1,1]; //普通陣列
//要儲存的資料是10個二進位制位，但是一個位元組是8位，so，需要16位,2個位元組
var binLen = binaryData.length;
var byteLen = Math.ceil(binLen/8);
var buffer = new ArrayBuffer(byteLen ); // 開闢兩個位元組的緩衝區
var byteData = new Uint8Array(buffer);
for(var i=0; i<byteLen ; i++) { //開始轉化為8進位制
  byteData[i] = 0;
  for(var j=i*8,k=7; k>=0&&j<binLen; j++,k--) {
    byteData[i] |= binaryData[j] << k;  
    //用按位或運算，將8個二進位制一組地組合到byteData中
  }
}
var data = new Blob([buffer],{type:"application/octet-stream"});
var downloadUrl = window.URL.createObjectURL(data);
var anchor = document.createElement("a");
anchor.href = downloadUrl;
anchor.download = "二進位制測試.bin";
anchor.click();
window.URL.revokeObjectURL(data);