解决kkFileView4.4.0版本pdf、word不能预览问题

这里使用的是http下载流url预览，遇到的问题。

官方使用指南：kkFileView - 在线文件预览

1 前端测试代码

1.1 官方示例代码

1.2 本人测试代码

注意：要给预览文件的url进行编码encodeURIComponent(Base64.encode(previewUrl))。

<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><title>Title</title></head>
<body>
<h2>在线预览</h2>
<button type="button" onclick="kkFileView()">点击在线预览</button>
</body>
</html>
<script>var Base64 = {// private property_keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",//从普通字符串转换成Base64字符串的函数encode : function (input) {var output = "";var chr1, chr2, chr3, enc1, enc2, enc3, enc4;var i = 0;input = Base64._utf8_encode(input);while (i < input.length) {chr1 = input.charCodeAt(i++);chr2 = input.charCodeAt(i++);chr3 = input.charCodeAt(i++);enc1 = chr1 >> 2;enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);enc4 = chr3 & 63;if (isNaN(chr2)) {enc3 = enc4 = 64;} else if (isNaN(chr3)) {enc4 = 64;}output = output +Base64._keyStr.charAt(enc1) + Base64._keyStr.charAt(enc2) +Base64._keyStr.charAt(enc3) + Base64._keyStr.charAt(enc4);}return output;},//从Base64字符串转换成普通字符串的函数decode : function (input) {var output = "";var chr1, chr2, chr3;var enc1, enc2, enc3, enc4;var i = 0;input = input.replace(/[^A-Za-z0-9+/=]/g, "");while (i < input.length) {enc1 = Base64._keyStr.indexOf(input.charAt(i++));enc2 = Base64._keyStr.indexOf(input.charAt(i++));enc3 = Base64._keyStr.indexOf(input.charAt(i++));enc4 = Base64._keyStr.indexOf(input.charAt(i++));chr1 = (enc1 << 2) | (enc2 >> 4);chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);chr3 = ((enc3 & 3) << 6) | enc4;output = output + String.fromCharCode(chr1);if (enc3 != 64) {output = output + String.fromCharCode(chr2);}if (enc4 != 64) {output = output + String.fromCharCode(chr3);}}output = Base64._utf8_decode(output);return output;},//将普通字符串转换成UTF8编码的函数_utf8_encode : function (string) {string = string.replace(/\r\n/g,"\n");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;},//将UTF8编码的字符串转换成普通字符串的函数_utf8_decode : function (utftext) {var string = "";var i = 0;var c = c1 = c2 = 0;while ( i < utftext.length ) {c = utftext.charCodeAt(i);if (c < 128) {string += String.fromCharCode(c);i++;}else if((c > 191) && (c < 224)) {c2 = utftext.charCodeAt(i+1);string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));i += 2;}else {c2 = utftext.charCodeAt(i+1);c3 = utftext.charCodeAt(i+2);string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));i += 3;}}return string;}}function kkFileView(){// pdf的文件流var originUrl  = 'http://192.168.1.58:8080/getFile?s/lV3bcibQiz34TStDR0NJ3tYfr1fqIvKRrtvEOy5ATi3a7u18wax87gN4DWjch/hcpeqQS8mQMoAYMDIXRzEpqtYk0H7DV/+pmYS/KtdPpk0tQrLSnT5OK8ND6QQgaTypPSswbJNvwhs+l5fE4GHLnvBX+kD9J42YAKO6VzAdzFmyonGjiAbegeLD4QspUcXXsdNSzz/7fDeRjDzc0M+HlMMS8/CiuMUmHqL4ErjuNF4Mn3s42UveYOHlukb0p4PCIJlhZeRBx4zXlTOcLlXItZKVb6gBVHVBH9e6ZpfTuIQJ4VRSN3twEOuIsBZ83w3SIepUH9oaA=';// 使用fullfilename=xxx给文件指定名称var previewUrl = originUrl + '&fullfilename=1.pdf';window.open('http://127.0.0.1:8012/onlinePreview?url='+encodeURIComponent(Base64.encode(previewUrl)))}
</script>

2 测试

点击在线预览按钮出现以下情况：

3 解决下载失败报错

3.1 报错信息

下载失败:org.springframework.web.client.HttpServerErrorException$InternalServerError: 500 Internal Server Error: [<!DOCTYPE html><html><head><title>Apache Tomcat/8.0.30 - Error report</title><style type="text/css">H1 {font-family:Tahoma,Arial,sans-serif;color:white;background-color:#525D76;font-size:22px;} H2 {fo... (1984 bytes)]