解决各大浏览器下载文件名显示不正确的情况
下载时，最关键的三步：
response.reset();//清空缓存区，防止存在某些字符使得下载的文件格式错误
response.setContentType("application/pdf;charset=UTF-8");//指定文件类型，其他类型可参见w3school的文档，也可参见下文的附录标准
response.setHeader("Content-Disposition", "attachment;filename=temp.pdf");// attachment后面一定是逗号，这个地方我就犯过错误，写成了:，结果死活不对
解决下载时，中文文件名显示不正确的方法：
理论依据：
浏览器能正确识别的编码格式，只要按照这样的编码来设置对应的Content-Disposition，那么应该就不会出现中文文件名的乱码问题了。
首先，Content-Disposition值可以有以下几种编码格式
1. 直接urlencode：
Content-Disposition: attachment; filename="struts2.0%E4%B8%AD%E6%96%87%E6%95%99%E7%A8%8B.chm"
2. Base64编码：
Content-Disposition: attachment; filename="=?UTF8?B?c3RydXRzMi4w5Lit5paH5pWZ56iLLmNobQ==?="
3. RFC2231规定的标准：
Content-Disposition: attachment; filename*=UTF-8''%E5%9B%9E%E6%89%A7.msg
4. 直接ISO编码的文件名：
Content-Disposition: attachment;filename="测试.txt"
然后，各浏览器支持的对应编码格式为：
1. IE浏览器，采用URLEncoder编码
2. Opera浏览器，采用filename*方式
3. Safari浏览器，采用ISO编码的中文输出
4. Chrome浏览器，采用Base64编码或ISO编码的中文输出
5. FireFox浏览器，采用Base64或filename*或ISO编码的中文输出
源代码：
private String getDownLoadFileName(String filename) {
String new_filename = null;
try {
new_filename = URLEncoder.encode(filename, "UTF8");
} catch (UnsupportedEncodingException e1) {
e1.printStackTrace();
}
HttpServletRequest request = ServletActionContext.getRequest();
String userAgent = request.getHeader("User-Agent");
// System.out.println(userAgent);
String rtn = "filename=\"" + new_filename + "\"";
// 如果没有UA，则默认使用IE的方式进行编码，因为毕竟IE还是占多数的
if (userAgent != null) {
userAgent = userAgent.toLowerCase();
// IE浏览器，只能采用URLEncoder编码
if (userAgent.indexOf("msie") != -1) {
rtn = "filename=\"" + new_filename + "\"";
}
// Opera浏览器只能采用filename*
else if (userAgent.indexOf("opera") != -1) {
rtn = "filename*=UTF-8''" + new_filename;
}
// Safari浏览器，只能采用ISO编码的中文输出
else if (userAgent.indexOf("safari") != -1) {
try {
rtn = "filename=\""
+ new String(filename.getBytes("UTF-8"),
"ISO8859-1") + "\"";
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
}
// Chrome浏览器，只能采用MimeUtility编码或ISO编码的中文输出
else if (userAgent.indexOf("applewebkit") != -1) {
try {
new_filename = MimeUtility
.encodeText(filename, "UTF8", "B");
} catch (UnsupportedEncodingException e) {
e.printStackTrace();
}
rtn = "filename=\"" + new_filename + "\"";
}
// FireFox浏览器，可以使用MimeUtility或filename*或ISO编码的中文输出
else if (userAgent.indexOf("mozilla") != -1) {
rtn = "filename*=UTF-8''" + new_filename;
}
}
return rtn;
}基本能解决大部分浏览器中文显示不正常的情况，但是，浏览器还有版本的，所以最好的方式就是能不用中文的时候，尽量别用中文
附录：
按照文件扩展名排列的 Mime 类型列表
| 扩展名 | 类型/子类型 |
|---|---|
| application/octet-stream | |
| 323 | text/h323 |
| acx | application/internet-property-stream |
| ai | application/postscript |
| aif | audio/x-aiff |
| aifc | audio/x-aiff |
| aiff | audio/x-aiff |
| asf | video/x-ms-asf |
| asr | video/x-ms-asf |
| asx | video/x-ms-asf |
| au | audio/basic |
| avi | video/x-msvideo |
| axs | application/olescript |
| bas | text/plain |
| bcpio | application/x-bcpio |
| bin | application/octet-stream |
| bmp | image/bmp |
| c | text/plain |
| cat | application/vnd.ms-pkiseccat |
| cdf | application/x-cdf |
| cer | application/x-x509-ca-cert |
| class | application/octet-stream |
| clp | application/x-msclip |
| cmx | image/x-cmx |
| cod | image/cis-cod |
| cpio | application/x-cpio |
| crd | application/x-mscardfile |
| crl | application/pkix-crl |
| crt | application/x-x509-ca-cert |
| csh | application/x-csh |
| css | text/css |
| dcr | application/x-director |
| der | application/x-x509-ca-cert |
| dir | application/x-director |
| dll | application/x-msdownload |
| dms | application/octet-stream |
| doc | application/msword |
| dot | application/msword |
| dvi | application/x-dvi |
| dxr | application/x-director |
| eps | application/postscript |
| etx | text/x-setext |
| evy | application/envoy |
| exe | application/octet-stream |
| fif | application/fractals |
| flr | x-world/x-vrml |
| gif | image/gif |
| gtar | application/x-gtar |
| gz | application/x-gzip |
| h | text/plain |
| hdf | application/x-hdf |
| hlp | application/winhlp |
| hqx | application/mac-binhex40 |
| hta | application/hta |
| htc | text/x-component |
| htm | text/html |
| html | text/html |
| htt | text/webviewhtml |
| ico | image/x-icon |
| ief | image/ief |
| iii | application/x-iphone |
| ins | application/x-internet-signup |
| isp | application/x-internet-signup |
| jfif | image/pipeg |
| jpe | image/jpeg |
| jpeg | image/jpeg |
| jpg | image/jpeg |
| js | application/x-javascript |
| latex | application/x-latex |
| lha | application/octet-stream |
| lsf | video/x-la-asf |
| lsx | video/x-la-asf |
| lzh | application/octet-stream |
| m13 | application/x-msmediaview |
| m14 | application/x-msmediaview |
| m3u | audio/x-mpegurl |
| man | application/x-troff-man |
| mdb | application/x-msaccess |
| me | application/x-troff-me |
| mht | message/rfc822 |
| mhtml | message/rfc822 |
| mid | audio/mid |
| mny | application/x-msmoney |
| mov | video/quicktime |
| movie | video/x-sgi-movie |
| mp2 | video/mpeg |
| mp3 | audio/mpeg |
| mpa | video/mpeg |
| mpe | video/mpeg |
| mpeg | video/mpeg |
| mpg | video/mpeg |
| mpp | application/vnd.ms-project |
| mpv2 | video/mpeg |
| ms | application/x-troff-ms |
| mvb | application/x-msmediaview |
| nws | message/rfc822 |
| oda | application/oda |
| p10 | application/pkcs10 |
| p12 | application/x-pkcs12 |
| p7b | application/x-pkcs7-certificates |
| p7c | application/x-pkcs7-mime |
| p7m | application/x-pkcs7-mime |
| p7r | application/x-pkcs7-certreqresp |
| p7s | application/x-pkcs7-signature |
| pbm | image/x-portable-bitmap |
| application/pdf | |
| pfx | application/x-pkcs12 |
| pgm | image/x-portable-graymap |
| pko | application/ynd.ms-pkipko |
| pma | application/x-perfmon |
| pmc | application/x-perfmon |
| pml | application/x-perfmon |
| pmr | application/x-perfmon |
| pmw | application/x-perfmon |
| pnm | image/x-portable-anymap |
| pot, | application/vnd.ms-powerpoint |
| ppm | image/x-portable-pixmap |
| pps | application/vnd.ms-powerpoint |
| ppt | application/vnd.ms-powerpoint |
| prf | application/pics-rules |
| ps | application/postscript |
| pub | application/x-mspublisher |
| qt | video/quicktime |
| ra | audio/x-pn-realaudio |
| ram | audio/x-pn-realaudio |
| ras | image/x-cmu-raster |
| rgb | image/x-rgb |
| rmi | audio/mid |
| roff | application/x-troff |
| rtf | application/rtf |
| rtx | text/richtext |
| scd | application/x-msschedule |
| sct | text/scriptlet |
| setpay | application/set-payment-initiation |
| setreg | application/set-registration-initiation |
| sh | application/x-sh |
| shar | application/x-shar |
| sit | application/x-stuffit |
| snd | audio/basic |
| spc | application/x-pkcs7-certificates |
| spl | application/futuresplash |
| src | application/x-wais-source |
| sst | application/vnd.ms-pkicertstore |
| stl | application/vnd.ms-pkistl |
| stm | text/html |
| svg | image/svg+xml |
| sv4cpio | application/x-sv4cpio |
| sv4crc | application/x-sv4crc |
| swf | application/x-shockwave-flash |
| t | application/x-troff |
| tar | application/x-tar |
| tcl | application/x-tcl |
| tex | application/x-tex |
| texi | application/x-texinfo |
| texinfo | application/x-texinfo |
| tgz | application/x-compressed |
| tif | image/tiff |
| tiff | image/tiff |
| tr | application/x-troff |
| trm | application/x-msterminal |
| tsv | text/tab-separated-values |
| txt | text/plain |
| uls | text/iuls |
| ustar | application/x-ustar |
| vcf | text/x-vcard |
| vrml | x-world/x-vrml |
| wav | audio/x-wav |
| wcm | application/vnd.ms-works |
| wdb | application/vnd.ms-works |
| wks | application/vnd.ms-works |
| wmf | application/x-msmetafile |
| wps | application/vnd.ms-works |
| wri | application/x-mswrite |
| wrl | x-world/x-vrml |
| wrz | x-world/x-vrml |
| xaf | x-world/x-vrml |
| xbm | image/x-xbitmap |
| xla | application/vnd.ms-excel |
| xlc | application/vnd.ms-excel |
| xlm | application/vnd.ms-excel |
| xls | application/vnd.ms-excel |
| xlt | application/vnd.ms-excel |
| xlw | application/vnd.ms-excel |
| xof | x-world/x-vrml |
| xpm | image/x-xpixmap |
| xwd | image/x-xwindowdump |
| z | application/x-compress |
| zip | application/zip |