base64转文件

我就是我 2022-05-29 06:26 894阅读 0赞

#### base64转文件 ####

/** * 文件流base64字符串后轉成文件 * @param {string} base64Data 數據 * @param {string} contentType 文件類型 */
    function base64ToToBlob(base64Data, contentType) {
        var bytes64 = atob(base64Data);
    
        var byteData = new ArrayBuffer(bytes64.length);//内存区域
    
        var array = new Uint8Array(byteData);//8位无符号整数
        for (var i = 0; i < bytes64.length; i++) {
            array[i] = bytes64.charCodeAt(i);//字符的 Unicode 编码
        }
        return new Blob([byteData], { type: contentType });
    }
    /** * blob保存为文件 * @param {Blob} blob數據 * @param {string} filename文件名 */
    function saveAs(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);
        }
    }

#### execl转base64服务端实现 ####

HSSFWorkbook workbook = new HSSFWorkbook();
    //一系列转换操作
    using (MemoryStream ms = new MemoryStream())
    {
        workbook.Write(ms);
        ms.Flush();
        ms.Position = 0;
        //sheet.Dispose();
        // workbook.Dispose();//一般只用写这一个就OK了，他会遍历并释放所有资源，但当前版本有问题所以只释放sheet
        return ms;
    }
    
    //再通过以下语句转成base64
    Convert.ToBase64String(ms.ToArray(), Base64FormattingOptions.None);

#### 其他相关js ####

/* *getFileBase64(file, fnc) //获取文件对象的base64 * *md5(string) //计算字符串md5 */
    
    function getFileBase64(file, fnc) { 
        var reader = new FileReader();
        reader.readAsDataURL(file);
        reader.onload = function (e) { 
            if (typeof fnc === "function") {
                fnc(e.target.result)
            }
        };
    }
    function md5(string) { 
        function RotateLeft(lValue, iShiftBits) { 
            return (lValue << iShiftBits) | (lValue >>> (32 - iShiftBits));
        }
        function AddUnsigned(lX, lY) { 
            var lX4, lY4, lX8, lY8, lResult;
            lX8 = (lX & 0x80000000);
            lY8 = (lY & 0x80000000);
            lX4 = (lX & 0x40000000);
            lY4 = (lY & 0x40000000);
            lResult = (lX & 0x3FFFFFFF) + (lY & 0x3FFFFFFF);
            if (lX4 & lY4) {
                return (lResult ^ 0x80000000 ^ lX8 ^ lY8);
            }
            if (lX4 | lY4) {
                if (lResult & 0x40000000) {
                    return (lResult ^ 0xC0000000 ^ lX8 ^ lY8);
                } else {
                    return (lResult ^ 0x40000000 ^ lX8 ^ lY8);
                }
            } else {
                return (lResult ^ lX8 ^ lY8);
            }
        }
        function F(x, y, z) { 
            return (x & y) | ((~x) & z);
        }
        function G(x, y, z) { 
            return (x & z) | (y & (~z));
        }
        function H(x, y, z) { 
            return (x ^ y ^ z);
        }
        function I(x, y, z) { 
            return (y ^ (x | (~z)));
        }
        function FF(a, b, c, d, x, s, ac) { 
            a = AddUnsigned(a, AddUnsigned(AddUnsigned(F(b, c, d), x), ac));
            return AddUnsigned(RotateLeft(a, s), b);
        }
        function GG(a, b, c, d, x, s, ac) { 
            a = AddUnsigned(a, AddUnsigned(AddUnsigned(G(b, c, d), x), ac));
            return AddUnsigned(RotateLeft(a, s), b);
        }
        function HH(a, b, c, d, x, s, ac) { 
            a = AddUnsigned(a, AddUnsigned(AddUnsigned(H(b, c, d), x), ac));
            return AddUnsigned(RotateLeft(a, s), b);
        }
        function II(a, b, c, d, x, s, ac) { 
            a = AddUnsigned(a, AddUnsigned(AddUnsigned(I(b, c, d), x), ac));
            return AddUnsigned(RotateLeft(a, s), b);
        }
        function ConvertToWordArray(string) { 
            var lWordCount;
            var lMessageLength = string.length;
            var lNumberOfWords_temp1 = lMessageLength + 8;
            var lNumberOfWords_temp2 = (lNumberOfWords_temp1 - (lNumberOfWords_temp1 % 64)) / 64;
            var lNumberOfWords = (lNumberOfWords_temp2 + 1) * 16;
            var lWordArray = Array(lNumberOfWords - 1);
            var lBytePosition = 0;
            var lByteCount = 0;
            while (lByteCount < lMessageLength) {
                lWordCount = (lByteCount - (lByteCount % 4)) / 4;
                lBytePosition = (lByteCount % 4) * 8;
                lWordArray[lWordCount] = (lWordArray[lWordCount] | (string.charCodeAt(lByteCount) << lBytePosition));
                lByteCount++;
            }
            lWordCount = (lByteCount - (lByteCount % 4)) / 4;
            lBytePosition = (lByteCount % 4) * 8;
            lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80 << lBytePosition);
            lWordArray[lNumberOfWords - 2] = lMessageLength << 3;
            lWordArray[lNumberOfWords - 1] = lMessageLength >>> 29;
            return lWordArray;
        }
        function WordToHex(lValue) { 
            var WordToHexValue = "", WordToHexValue_temp = "", lByte, lCount;
            for (lCount = 0; lCount <= 3; lCount++) {
                lByte = (lValue >>> (lCount * 8)) & 255;
                WordToHexValue_temp = "0" + lByte.toString(16);
                WordToHexValue = WordToHexValue + WordToHexValue_temp.substr(WordToHexValue_temp.length - 2, 2);
            }
            return WordToHexValue;
        }
        function Utf8Encode(string) { 
            var utftext = "";
            for (var n = 0; n < string.length; n++) {
                var c = string.charCodeAt(n);
                if (c < 128) {
                    utftext += String.fromCharCode(c);
                } else if ((c > 127) && (c < 2048)) {
                    utftext += String.fromCharCode((c >> 6) | 192);
                    utftext += String.fromCharCode((c & 63) | 128);
                } else {
                    utftext += String.fromCharCode((c >> 12) | 224);
                    utftext += String.fromCharCode(((c >> 6) & 63) | 128);
                    utftext += String.fromCharCode((c & 63) | 128);
                }
            }
            return utftext;
        }
    
        var x = Array();
        var k, AA, BB, CC, DD, a, b, c, d;
        var S11 = 7, S12 = 12, S13 = 17, S14 = 22;
        var S21 = 5, S22 = 9, S23 = 14, S24 = 20;
        var S31 = 4, S32 = 11, S33 = 16, S34 = 23;
        var S41 = 6, S42 = 10, S43 = 15, S44 = 21;
        string = Utf8Encode(string);
        x = ConvertToWordArray(string);
        a = 0x67452301;
        b = 0xEFCDAB89;
        c = 0x98BADCFE;
        d = 0x10325476;
        for (k = 0; k < x.length; k += 16) {
            AA = a;
            BB = b;
            CC = c;
            DD = d;
            a = FF(a, b, c, d, x[k + 0], S11, 0xD76AA478);
            d = FF(d, a, b, c, x[k + 1], S12, 0xE8C7B756);
            c = FF(c, d, a, b, x[k + 2], S13, 0x242070DB);
            b = FF(b, c, d, a, x[k + 3], S14, 0xC1BDCEEE);
            a = FF(a, b, c, d, x[k + 4], S11, 0xF57C0FAF);
            d = FF(d, a, b, c, x[k + 5], S12, 0x4787C62A);
            c = FF(c, d, a, b, x[k + 6], S13, 0xA8304613);
            b = FF(b, c, d, a, x[k + 7], S14, 0xFD469501);
            a = FF(a, b, c, d, x[k + 8], S11, 0x698098D8);
            d = FF(d, a, b, c, x[k + 9], S12, 0x8B44F7AF);
            c = FF(c, d, a, b, x[k + 10], S13, 0xFFFF5BB1);
            b = FF(b, c, d, a, x[k + 11], S14, 0x895CD7BE);
            a = FF(a, b, c, d, x[k + 12], S11, 0x6B901122);
            d = FF(d, a, b, c, x[k + 13], S12, 0xFD987193);
            c = FF(c, d, a, b, x[k + 14], S13, 0xA679438E);
            b = FF(b, c, d, a, x[k + 15], S14, 0x49B40821);
            a = GG(a, b, c, d, x[k + 1], S21, 0xF61E2562);
            d = GG(d, a, b, c, x[k + 6], S22, 0xC040B340);
            c = GG(c, d, a, b, x[k + 11], S23, 0x265E5A51);
            b = GG(b, c, d, a, x[k + 0], S24, 0xE9B6C7AA);
            a = GG(a, b, c, d, x[k + 5], S21, 0xD62F105D);
            d = GG(d, a, b, c, x[k + 10], S22, 0x2441453);
            c = GG(c, d, a, b, x[k + 15], S23, 0xD8A1E681);
            b = GG(b, c, d, a, x[k + 4], S24, 0xE7D3FBC8);
            a = GG(a, b, c, d, x[k + 9], S21, 0x21E1CDE6);
            d = GG(d, a, b, c, x[k + 14], S22, 0xC33707D6);
            c = GG(c, d, a, b, x[k + 3], S23, 0xF4D50D87);
            b = GG(b, c, d, a, x[k + 8], S24, 0x455A14ED);
            a = GG(a, b, c, d, x[k + 13], S21, 0xA9E3E905);
            d = GG(d, a, b, c, x[k + 2], S22, 0xFCEFA3F8);
            c = GG(c, d, a, b, x[k + 7], S23, 0x676F02D9);
            b = GG(b, c, d, a, x[k + 12], S24, 0x8D2A4C8A);
            a = HH(a, b, c, d, x[k + 5], S31, 0xFFFA3942);
            d = HH(d, a, b, c, x[k + 8], S32, 0x8771F681);
            c = HH(c, d, a, b, x[k + 11], S33, 0x6D9D6122);
            b = HH(b, c, d, a, x[k + 14], S34, 0xFDE5380C);
            a = HH(a, b, c, d, x[k + 1], S31, 0xA4BEEA44);
            d = HH(d, a, b, c, x[k + 4], S32, 0x4BDECFA9);
            c = HH(c, d, a, b, x[k + 7], S33, 0xF6BB4B60);
            b = HH(b, c, d, a, x[k + 10], S34, 0xBEBFBC70);
            a = HH(a, b, c, d, x[k + 13], S31, 0x289B7EC6);
            d = HH(d, a, b, c, x[k + 0], S32, 0xEAA127FA);
            c = HH(c, d, a, b, x[k + 3], S33, 0xD4EF3085);
            b = HH(b, c, d, a, x[k + 6], S34, 0x4881D05);
            a = HH(a, b, c, d, x[k + 9], S31, 0xD9D4D039);
            d = HH(d, a, b, c, x[k + 12], S32, 0xE6DB99E5);
            c = HH(c, d, a, b, x[k + 15], S33, 0x1FA27CF8);
            b = HH(b, c, d, a, x[k + 2], S34, 0xC4AC5665);
            a = II(a, b, c, d, x[k + 0], S41, 0xF4292244);
            d = II(d, a, b, c, x[k + 7], S42, 0x432AFF97);
            c = II(c, d, a, b, x[k + 14], S43, 0xAB9423A7);
            b = II(b, c, d, a, x[k + 5], S44, 0xFC93A039);
            a = II(a, b, c, d, x[k + 12], S41, 0x655B59C3);
            d = II(d, a, b, c, x[k + 3], S42, 0x8F0CCC92);
            c = II(c, d, a, b, x[k + 10], S43, 0xFFEFF47D);
            b = II(b, c, d, a, x[k + 1], S44, 0x85845DD1);
            a = II(a, b, c, d, x[k + 8], S41, 0x6FA87E4F);
            d = II(d, a, b, c, x[k + 15], S42, 0xFE2CE6E0);
            c = II(c, d, a, b, x[k + 6], S43, 0xA3014314);
            b = II(b, c, d, a, x[k + 13], S44, 0x4E0811A1);
            a = II(a, b, c, d, x[k + 4], S41, 0xF7537E82);
            d = II(d, a, b, c, x[k + 11], S42, 0xBD3AF235);
            c = II(c, d, a, b, x[k + 2], S43, 0x2AD7D2BB);
            b = II(b, c, d, a, x[k + 9], S44, 0xEB86D391);
            a = AddUnsigned(a, AA);
            b = AddUnsigned(b, BB);
            c = AddUnsigned(c, CC);
            d = AddUnsigned(d, DD);
        }
        var temp = WordToHex(a) + WordToHex(b) + WordToHex(c) + WordToHex(d);
        return temp.toLowerCase();
    }