Java文件下載

Java文件下載的幾種方式

public HttpServletResponse download(String path, HttpServletResponse response) {
        try {
            // path是指欲下載的文件的路徑。
            File file = new File(path);
            // 取得文件名。
            String filename = file.getName();
            // 取得文件的後綴名。
            String ext = filename.substring(filename.lastIndexOf(".") + 1).toUpperCase();

            // 以流的形式下載文件。
            InputStream fis = new BufferedInputStream(new FileInputStream(path));
            byte[] buffer = new byte[fis.available()];
            fis.read(buffer);
            fis.close();
            // 清空response
            response.reset();
            // 設置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 {
        // 下載本地文件
        String fileName = "Operator.doc".toString(); // 文件的默認保存名
        // 讀到流中
        InputStream inStream = new FileInputStream("c:/Operator.doc");// 文件的存放路徑
        // 設置輸出的格式
        response.reset();
        response.setContentType("bin");
        response.addHeader("Content-Disposition", "attachment; filename=\"" + fileName + "\"");
        // 循環取出流中的數據
        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 {
        // 下載網絡文件
        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();
        }
    }

//支持在線打開文件的一種方式

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(); // 很是重要
        if (isOnLine) { // 在線打開方式
            URL u = new URL("file:///" + filePath);
            response.setContentType(u.openConnection().getContentType());
            response.setHeader("Content-Disposition", "inline; filename=" + f.getName());
            // 文件名應該編碼成UTF-8
        } else { // 純下載方式
            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();
    }

=================== 以上爲轉載內容 ====================

本身寫的下載本地文件的代碼

public void download(String filePath, String fileName, HttpServletResponse response) throws UnsupportedEncodingException {
        //獲取網站部署路徑(經過ServletContext對象)，用於肯定下載文件位置，從而實現下載  
        String filepath = new String(filePath.getBytes("ISO-8859-1"),"utf-8").toString();  
        String filename = new String(fileName.getBytes("ISO-8859-1"),"utf-8").toString(); 
        try {  
        	File file = new File(filepath + "/" + filename);  
            FileInputStream in = new FileInputStream(file); 
            ServletOutputStream sos = response.getOutputStream();  
            // 設置輸出格式
            response.reset();
            response.setContentType("application/x-download");
            response.setHeader("Content-Disposition", "inline;filename =" + fileName);
            //建立緩衝區  
            byte buffer[] = new byte[1024];  
            int len = 0;  
            // 循環將輸入流中的內容讀取到緩衝區當中  
            while ((len = in.read(buffer)) > 0) {  
                sos.write(buffer, 0, len);  
            } 
            in.close();  
            sos.close();  
            sos.flush();
        } catch (IOException e) {  
            e.printStackTrace();  
        } 
    }