一. ContentType
我们在进行文件下载的时候,后端往往需要通过如下方式设置ContentType
import org.springframework.http.MediaType;import javax.annotation.Resource;import javax.servlet.http.HttpServletResponse;@Resourceprivate HttpServletResponse response;// 省略...response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
其中用到了MediaType,MediaType是一种媒体类型,指定资源的形式。
浏览器通过获取response响应中的Content-Type所对应的类型对资源进行解析。
常用的Content-Type如下表所示,其中
application/octet-stream
: 是比较常用的类型,可用于任何类型的文件下载。application/x-msdownload
: 网上很多文件说用此Content-Type进行文件下载,虽然也能实现其功能,但由下表可知,此类型对应着.ddl 和 .exe 文件。
HTTP Content-type对照表
文件扩展名 | Content-Type(Mime-Type) | 文件扩展名 | Content-Type(Mime-Type) |
---|---|---|---|
.*( 二进制流,不知道下载文件类型) | application/octet-stream | .tif | image/tiff |
.001 | application/x-001 | .301 | application/x-301 |
.323 | text/h323 | .906 | application/x-906 |
.907 | drawing/907 | .a11 | application/x-a11 |
.acp | audio/x-mei-aac | .ai | application/postscript |
.aif | audio/aiff | .aifc | audio/aiff |
.aiff | audio/aiff | .anv | application/x-anv |
.asa | text/asa | .asf | video/x-ms-asf |
.asp | text/asp | .asx | video/x-ms-asf |
.au | audio/basic | .avi | video/avi |
.awf | application/vnd.adobe.workflow | .biz | text/xml |
.bmp | application/x-bmp | .bot | application/x-bot |
.c4t | application/x-c4t | .c90 | application/x-c90 |
.cal | application/x-cals | .cat | application/vnd.ms-pki.seccat |
.cdf | application/x-netcdf | .cdr | application/x-cdr |
.cel | application/x-cel | .cer | application/x-x509-ca-cert |
.cg4 | application/x-g4 | .cgm | application/x-cgm |
.cit | application/x-cit | .class | java/* |
.cml | text/xml | .cmp | application/x-cmp |
.cmx | application/x-cmx | .cot | application/x-cot |
.crl | application/pkix-crl | .crt | application/x-x509-ca-cert |
.csi | application/x-csi | .css | text/css |
.cut | application/x-cut | .dbf | application/x-dbf |
.dbm | application/x-dbm | .dbx | application/x-dbx |
.dcd | text/xml | .dcx | application/x-dcx |
.der | application/x-x509-ca-cert | .dgn | application/x-dgn |
.dib | application/x-dib | .dll | application/x-msdownload |
.doc | application/msword | .dot | application/msword |
.drw | application/x-drw | .dtd | text/xml |
.dwf | Model/vnd.dwf | .dwf | application/x-dwf |
.dwg | application/x-dwg | .dxb | application/x-dxb |
.dxf | application/x-dxf | .edn | application/vnd.adobe.edn |
.emf | application/x-emf | .eml | message/rfc822 |
.ent | text/xml | .epi | application/x-epi |
.eps | application/x-ps | .eps | application/postscript |
.etd | application/x-ebx | .exe | application/x-msdownload |
.fax | image/fax | .fdf | application/vnd.fdf |
.fif | application/fractals | .fo | text/xml |
.frm | application/x-frm | .g4 | application/x-g4 |
.gbr | application/x-gbr | . | application/x- |
.gif | image/gif | .gl2 | application/x-gl2 |
.gp4 | application/x-gp4 | .hgl | application/x-hgl |
.hmr | application/x-hmr | .hpg | application/x-hpgl |
.hpl | application/x-hpl | .hqx | application/mac-binhex40 |
.hrf | application/x-hrf | .hta | application/hta |
.htc | text/x-component | .htm | text/html |
.html | text/html | .htt | text/webviewhtml |
.htx | text/html | .icb | application/x-icb |
.ico | image/x-icon | .ico | application/x-ico |
.iff | application/x-iff | .ig4 | application/x-g4 |
.igs | application/x-igs | .iii | application/x-iphone |
.img | application/x-img | .ins | application/x-internet-signup |
.isp | application/x-internet-signup | .IVF | video/x-ivf |
.java | java/* | .jfif | image/jpeg |
.jpe | image/jpeg | .jpe | application/x-jpe |
.jpeg | image/jpeg | .jpg | image/jpeg |
.jpg | application/x-jpg | .js | application/x-javascript |
.jsp | text/html | .la1 | audio/x-liquid-file |
.lar | application/x-laplayer-reg | .latex | application/x-latex |
.lavs | audio/x-liquid-secure | .lbm | application/x-lbm |
.lmsff | audio/x-la-lms | .ls | application/x-javascript |
.ltr | application/x-ltr | .m1v | video/x-mpeg |
.m2v | video/x-mpeg | .m3u | audio/mpegurl |
.m4e | video/mpeg4 | .mac | application/x-mac |
.man | application/x-troff-man | .math | text/xml |
.mdb | application/msaccess | .mdb | application/x-mdb |
.mfp | application/x-shockwave-flash | .mht | message/rfc822 |
.mhtml | message/rfc822 | .mi | application/x-mi |
.mid | audio/mid | .midi | audio/mid |
.mil | application/x-mil | .mml | text/xml |
.mnd | audio/x-musicnet-download | .mns | audio/x-musicnet-stream |
.mocha | application/x-javascript | .movie | video/x-sgi-movie |
.mp1 | audio/mp1 | .mp2 | audio/mp2 |
.mp2v | video/mpeg | .mp3 | audio/mp3 |
.mp4 | video/mpeg4 | .mpa | video/x-mpg |
.mpd | application/vnd.ms-project | .mpe | video/x-mpeg |
.mpeg | video/mpg | .mpg | video/mpg |
.mpga | audio/rn-mpeg | .mpp | application/vnd.ms-project |
.mps | video/x-mpeg | .mpt | application/vnd.ms-project |
.mpv | video/mpg | .mpv2 | video/mpeg |
.mpw | application/vnd.ms-project | .mpx | application/vnd.ms-project |
.mtx | text/xml | .mxp | application/x-mmxp |
.net | image/pnetvue | .nrf | application/x-nrf |
.nws | message/rfc822 | .odc | text/x-ms-odc |
.out | application/x-out | .p10 | application/pkcs10 |
.p12 | application/x-pkcs12 | .p7b | application/x-pkcs7-certificates |
.p7c | application/pkcs7-mime | .p7m | application/pkcs7-mime |
.p7r | application/x-pkcs7-certreqresp | .p7s | application/pkcs7-signature |
.pc5 | application/x-pc5 | .pci | application/x-pci |
.pcl | application/x-pcl | .pcx | application/x-pcx |
application/pdf | application/pdf | ||
.pdx | application/vnd.adobe.pdx | .pfx | application/x-pkcs12 |
.pgl | application/x-pgl | .pic | application/x-pic |
.pko | application/vnd.ms-pki.pko | .pl | application/x-perl |
.plg | text/html | .pls | audio/scpls |
.plt | application/x-plt | .png | image/png |
.png | application/x-png | .pot | application/vnd.ms-powerpoint |
.ppa | application/vnd.ms-powerpoint | .ppm | application/x-ppm |
.pps | application/vnd.ms-powerpoint | .ppt | application/vnd.ms-powerpoint |
.ppt | application/x-ppt | .pr | application/x-pr |
.prf | application/pics-rules | .prn | application/x-prn |
.prt | application/x-prt | .ps | application/x-ps |
.ps | application/postscript | .ptn | application/x-ptn |
.pwz | application/vnd.ms-powerpoint | .r3t | text/vnd.rn-realtext3d |
.ra | audio/vnd.rn-realaudio | .ram | audio/x-pn-realaudio |
.ras | application/x-ras | .rat | application/rat-file |
.rdf | text/xml | .rec | application/vnd.rn-recording |
.red | application/x-red | .rgb | application/x-rgb |
.rjs | application/vnd.rn-realsystem-rjs | .rjt | application/vnd.rn-realsystem-rjt |
.rlc | application/x-rlc | .rle | application/x-rle |
.rm | application/vnd.rn-realmedia | .rmf | application/vnd.adobe.rmf |
.rmi | audio/mid | .rmj | application/vnd.rn-realsystem-rmj |
.rmm | audio/x-pn-realaudio | .rmp | application/vnd.rn-rn_music_package |
.rms | application/vnd.rn-realmedia-secure | .rmvb | application/vnd.rn-realmedia-vbr |
.rmx | application/vnd.rn-realsystem-rmx | .rnx | application/vnd.rn-realplayer |
.rp | image/vnd.rn-realpix | .rpm | audio/x-pn-realaudio-plugin |
.rsml | application/vnd.rn-rsml | .rt | text/vnd.rn-realtext |
.rtf | application/msword | .rtf | application/x-rtf |
.rv | video/vnd.rn-realvideo | .sam | application/x-sam |
.sat | application/x-sat | .sdp | application/sdp |
.sdw | application/x-sdw | .sit | application/x-stuffit |
.slb | application/x-slb | .sld | application/x-sld |
.slk | drawing/x-slk | .smi | application/smil |
.smil | application/smil | .smk | application/x-smk |
.snd | audio/basic | .sol | text/plain |
.sor | text/plain | .spc | application/x-pkcs7-certificates |
.spl | application/futuresplash | .spp | text/xml |
.ssm | application/streamingmedia | .sst | application/vnd.ms-pki.certstore |
.stl | application/vnd.ms-pki.stl | .stm | text/html |
.sty | application/x-sty | .svg | text/xml |
.swf | application/x-shockwave-flash | .tdf | application/x-tdf |
.tg4 | application/x-tg4 | .tga | application/x-tga |
.tif | image/tiff | .tif | application/x-tif |
.tiff | image/tiff | .tld | text/xml |
.top | drawing/x-top | .torrent | application/x-bittorrent |
.tsd | text/xml | .txt | text/plain |
.uin | application/x-icq | .uls | text/iuls |
.vcf | text/x-vcard | .vda | application/x-vda |
.vdx | application/vnd.visio | .vml | text/xml |
.vpg | application/x-vpeg005 | .vsd | application/vnd.visio |
.vsd | application/x-vsd | .vss | application/vnd.visio |
.vst | application/vnd.visio | .vst | application/x-vst |
.vsw | application/vnd.visio | .vsx | application/vnd.visio |
.vtx | application/vnd.visio | .vxml | text/xml |
.wav | audio/wav | .wax | audio/x-ms-wax |
.wb1 | application/x-wb1 | .wb2 | application/x-wb2 |
.wb3 | application/x-wb3 | .wbmp | image/vnd.wap.wbmp |
.wiz | application/msword | .wk3 | application/x-wk3 |
.wk4 | application/x-wk4 | .wkq | application/x-wkq |
.wks | application/x-wks | .wm | video/x-ms-wm |
.wma | audio/x-ms-wma | .wmd | application/x-ms-wmd |
.wmf | application/x-wmf | .wml | text/vnd.wap.wml |
.wmv | video/x-ms-wmv | .wmx | video/x-ms-wmx |
.wmz | application/x-ms-wmz | .wp6 | application/x-wp6 |
.wpd | application/x-wpd | .wpg | application/x-wpg |
.wpl | application/vnd.ms-wpl | .wq1 | application/x-wq1 |
.wr1 | application/x-wr1 | .wri | application/x-wri |
.wrk | application/x-wrk | .ws | application/x-ws |
.ws2 | application/x-ws | .wsc | text/scriptlet |
.wsdl | text/xml | .wvx | video/x-ms-wvx |
.xdp | application/vnd.adobe.xdp | .xdr | text/xml |
.xfd | application/vnd.adobe.xfd | .xfdf | application/vnd.adobe.xfdf |
.xhtml | text/html | .xls | application/vnd.ms-excel |
.xls | application/x-xls | .xlw | application/x-xlw |
.xml | text/xml | .xpl | audio/scpls |
.xq | text/xml | .xql | text/xml |
.xquery | text/xml | .xsd | text/xml |
.xsl | text/xml | .xslt | text/xml |
.xwd | application/x-xwd | .x_b | application/x-x_b |
.sis | application/vnd.symbian.install | .sisx | application/vnd.symbian.install |
.x_t | application/x-x_t | .ipa | application/vnd.iphone |
.apk | application/vnd.android.package-archive | .xap | application/x-silverlight-app |
二. a标签download属性
2.1 下载同源静态资源文件
如下图所示,在static/img
文件夹下保存着图片静态资源.
😵如果我们通过a标签超链接的方式直接访问,浏览器会以新标签页的方式打开
<!DOCTYPE html><html lang="en" xmlns:th="http://www.thymeleaf.org"><head> <meta charset="UTF-8"> <title>Title</title></head><body><div> <a th:href="@{/img/test.png}">非跨域图片</a></div>
💪若我们给a标签添加了download属性
<!DOCTYPE html><html lang="en" xmlns:th="http://www.thymeleaf.org"><head> <meta charset="UTF-8"> <title>Title</title></head><body><div> <a th:href="@{/img/test.png}" download>非跨域图片</a></div>
❗❗❗这种a标签配合download属性下载静态资源的方式,只适用于同源静态资源。
如果非同源的图片等。还是会直接打开,并不会触发下载。
2.2 下载非同源静态资源文件
<!DOCTYPE html><html lang="en"><head> <meta charset="UTF-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title></title></head><body> <a data-type="img" href="https://img-blog.yssmx.com/c8175b65d44d4316873590f19dfadd3b.gif">点击下载图片1</a> <a data-type="img" href="https://img-blog.yssmx.com/b2770c6e75cb478791f3b80f8448e2ba.png">点击下载图片2</a></body><script src="https://code.jquery.com/jquery-3.6.3.js"></script><script> $(function() { $("[data-type='img']").click(async function(event) { // 阻止a标签默认事件的触发 event.preventDefault(); const { currentTarget: { href } } = event; if (!href) { return; } // 通过fetch访问图片url,获取Blob对象 try { const response = await fetch(href); const blob = await response.blob(); const blobUrl = URL.createObjectURL(blob); // 创建a标签,并触发点击事件 const aElement = document.createElement("a"); aElement.href = blobUrl; // 获取数组的最后一个元素 aElement.download = href.split('/').at(-1); aElement.click(); // 从内存中移除blobUrl URL.revokeObjectURL(blobUrl); } catch (error) { console.log(error); } }) })</script></html>
2.3 后台可省略Content-Disposition
通过编程方式下载文件,往往需要在response的header中设置Content-Disposition来指定下载文件的名称,如下代码所示。
import javax.servlet.http.HttpServletResponse;import javax.annotation.Resource;@Resourceprivate HttpServletResponse response;// 省略...response.setContentType("application/octet-stream");response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(文件名, "UTF-8"));
如果我们在前台通过download指定了下载文件的名称和格式
<a th:href="@{/test24/fileDownload}" download="前台指定名称.txt">超链接直接下载文件</a>
则后台的代码可省略Content-Disposition的设置
// 省略Controller...@GetMapping("/fileDownload")public ResponseEntity<byte[]> fileDownload() throws Exception { // 读取本地的文件 String filePath = "/temp/A110120119/测试文件.text"; ClassPathResource readFile = new ClassPathResource(filePath); // 设置响应头,把文件名称放入响应头中,确保文件可下载 HttpHeaders headers = new HttpHeaders(); // 👇👇👇被注释掉 // headers.set("Content-Disposition", "attachment;filename=" + URLEncoder.encode(readFile.getFilename(), "UTF-8")); headers.setContentType(MediaType.APPLICATION_OCTET_STREAM); // 获取File对象 File file = readFile.getFile(); Path path = Paths.get(file.toURI()); // 获取File对象的字节码文件 byte[] bytes = Files.readAllBytes(path); return new ResponseEntity<>(bytes, headers, HttpStatus.OK);}
⏹效果如下所示文章来源:https://www.toymoban.com/news/detail-785324.html
文章来源地址https://www.toymoban.com/news/detail-785324.html
到了这里,关于文件下载 response响应ContentType与a标签download属性的文章就介绍完了。如果您还想了解更多内容,请在右上角搜索TOY模板网以前的文章或继续浏览下面的相关文章,希望大家以后多多支持TOY模板网!