Java文件下载的几种方式

支持浏览器打开：
1.web.xml

<mime-mapping>
		<extension>doc</extension>
		<mime-type>application/msword</mime-type>
	</mime-mapping>
	<mime-mapping>
		<extension>xls</extension>
		<mime-type>application/msexcel</mime-type>
	</mime-mapping>
	<mime-mapping>
		<extension>pdf</extension>
		<mime-type>application/pdf</mime-type>
	</mime-mapping>

2. "application/pdf" & inline

response.setContentType("application/pdf");
response.addHeader("Content-Disposition", "inline; filename=\"" + displayName + "\"");

//1.设置文件ContentType类型，这样设置，会自动判断下载文件类型  
response.setContentType("multipart/form-data");

http://blog.csdn.net/air291988889/article/details/8235281

public HttpServletResponse download(String path, HttpServletResponse response) {
        try {
// path是指欲下载的文件的路径。
            File file = new File(path);
// 取得文件名。
            String filename = file.getName();
// 取得文件的后缀名。
            String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();

// 以流的形式下载文件。
            InputStream fis = new BufferedInputStream(new FileInputStream(path));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();
// 清空response
            response.reset();
// 设置response的Header
            response.addHeader("Content-Disposition", "attachment;filename=" + new String(filename.getBytes()));
            response.addHeader("Content-Length", "" + file.length());
            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
            toClient.write(buffer);
            toClient.flush();
            toClient.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        return response;
    }

    public void downloadLocal(HttpServletResponse response) throws FileNotFoundException {
// 下载本地文件
        String fileName = "Operator.doc".toString(); // 文件的默认保存名
// 读到流中
        InputStream inStream = new FileInputStream("c:/Operator.doc");// 文件的存放路径
// 设置输出的格式
        response.reset();
        response.setContentType("bin");
        response.addHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
// 循环取出流中的数据
        byte[] b = new byte[100];
        int len;
        try {
            while ((len = inStream.read(b)) > 0)
                response.getOutputStream().write(b, 0, len);
            inStream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void downloadNet(HttpServletResponse response) throws MalformedURLException {
// 下载网络文件
        int bytesum = 0;
        int byteread = 0;

        URL url = new URL("windine.blogdriver.com/logo.gif");

        try {
            URLConnection conn = url.openConnection();
            InputStream inStream = conn.getInputStream();
            FileOutputStream fs = new FileOutputStream("c:/abc.gif");

            byte[] buffer = new byte[1204];
            int length;
            while ((byteread = inStream.read(buffer)) != -1) {
                bytesum += byteread;
                System.out.println(bytesum);
                fs.write(buffer, 0, byteread);
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    //支持在线打开文件的一种方式
    public void downLoad(String filePath, HttpServletResponse response, boolean isOnLine) throws Exception {
        File f = new File(filePath);
        if (!f.exists()) {
            response.sendError(404, "File not found!");
            return;
        }
        BufferedInputStream br = new BufferedInputStream(new FileInputStream(f));
        byte[] buf = new byte[1024];
        int len = 0;

        response.reset(); // 非常重要
        if (isOnLine) { // 在线打开方式
            URL u = new URL("file:///" + filePath);
            response.setContentType(u.openConnection().getContentType());
            response.setHeader("Content-Disposition", "inline; filename=" + f.getName());
// 文件名应该编码成UTF-8
        } else { // 纯下载方式
            response.setContentType("application/x-msdownload");
            response.setHeader("Content-Disposition", "attachment; filename=" + f.getName());
        }
        OutputStream out = response.getOutputStream();
        while ((len = br.read(buf)) > 0)
            out.write(buf, 0, len);
        br.close();
        out.close();
    }

Java文件下载ContentType设置 http://blog.csdn.net/fyg0072/article/details/7260665
文件类型如下:

".*"="application/octet-stream"

".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"

".gcd"="application/x-gcd"

".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"

".pdf"="application/pdf"

".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"

".x_t"="application/x-x_t"