"File Download" Java download files in several ways

1. Download it in a streaming fashion.

　　Public httpservletresponse Download (String path, httpservletresponse response) {try {//path = file to download            The path.            File File = new file (path);            Gets the file name.            String filename = File.getname ();            Gets the suffix name of the file.            String ext = filename.substring (Filename.lastindexof (".") + 1). toUpperCase ();            Download the file in the form of a stream.            InputStream fis = new Bufferedinputstream (new FileInputStream (path));            byte[] buffer = new byte[fis.available ()];            Fis.read (buffer);            Fis.close ();            Empty response Response.reset (); Set Response header Response.AddHeader ("Content-disposition", "attachment;filename=" + New String (filename.get            Bytes ()));            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; }

2. Download Local Files

public void downloadlocal (HttpServletResponse response) throws FileNotFoundException {        //download local file        String FileName = "Operator.doc". toString (); The default save name for the file//        read into the stream        inputstream instream = new FileInputStream ("C:/operator.doc");//file storage path        //Set output format        Response.reset ();        Response.setcontenttype ("bin");        Response.AddHeader ("Content-disposition", "attachment; Filename=\ "" + fileName + "\" ");        Loop out the data in the stream        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 ();        }    }

3. Download network files

public void Downloadnet (HttpServletResponse response) throws Malformedurlexception {        //download network file        int bytesum = 0;< C2/>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 (); c19/>}    }

4. Support for Online open mode

　　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 ();            Very important if (IsOnLine) {//online open mode url u = new URL ("file:///" + FilePath);            Response.setcontenttype (U.openconnection (). getContentType ()); Response.setheader ("content-disposition", "inline;            Filename= "+ f.getname ());            The file name should be encoded as UTF-8} else {//Pure download mode 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 (); }

"File Download" Java download files in several ways