@GetMapping("/file/download")
    public void fileDownload(HttpServletResponse response, @RequestParam("filePath") String filePath) {
        File file = new File(filePath);
        if (!file.exists()) {
            throw new BusinessException("當(dāng)前下載的文件不存在，請(qǐng)檢查路徑是否正確");
        }
        // 將文件寫入輸入流
        try (InputStream is = new BufferedInputStream(Files.newInputStream(file.toPath()))) {
            // 一次性讀取到內(nèi)存中
            byte[] buffer = new byte[is.available()];
            int read = is.read(buffer);
            // 清空 response
            response.reset();
            response.setCharacterEncoding("UTF-8");
            // Content-Disposition的作用：告知瀏覽器以何種方式顯示響應(yīng)返回的文件，用瀏覽器打開(kāi)還是以附件的形式下載到本地保存
            // attachment表示以附件方式下載   inline表示在線打開(kāi)   "Content-Disposition: inline; filename=文件名.mp3"
            // filename表示文件的默認(rèn)名稱，因?yàn)榫W(wǎng)絡(luò)傳輸只支持URL編碼的相關(guān)支付，因此需要將文件名URL編碼后進(jìn)行傳輸,前端收到后需要反編碼才能獲取到真正的名稱
            response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(file.getName(), "UTF-8"));
            // 告知瀏覽器文件的大小
            response.addHeader("Content-Length", "" + file.length());
            OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());
            response.setContentType("application/octet-stream");
            outputStream.write(buffer);
            outputStream.flush();
            outputStream.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @GetMapping("/file/download")
    public void fileDownload(HttpServletResponse response, @RequestParam("filePath") String filePath) {
        File file = new File(filePath);
        if (!file.exists()) {
            throw new BusinessException("當(dāng)前下載的文件不存在，請(qǐng)檢查路徑是否正確");
        }
        // 清空 response
        response.reset();
        response.setCharacterEncoding("UTF-8");
        response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(file.getName(), "UTF-8"));
        response.setContentType("application/octet-stream");
        // 將文件讀到輸入流中
        try (InputStream is = new BufferedInputStream(Files.newInputStream(file.toPath()))) {
            OutputStream outputStream = new BufferedOutputStream(response.getOutputStream());
            byte[] buffer = new byte[1024];
            int len;
            //從輸入流中讀取一定數(shù)量的字節(jié)，并將其存儲(chǔ)在緩沖區(qū)字節(jié)數(shù)組中，讀到末尾返回-1
            while((len = is.read(buffer)) > 0){
                outputStream.write(buffer, 0, len);
            }
            outputStream.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @GetMapping("/net/download")
    public void netDownload(HttpServletResponse response, @RequestParam("fileAddress") String fileAddress, @RequestParam("filename") String filename) {
        try {
            URL url = new URL(fileAddress);
            URLConnection conn = url.openConnection();
            InputStream inputStream = conn.getInputStream();
            response.reset();
            response.setContentType(conn.getContentType());
            response.setHeader("Content-Disposition", "attachment; filename=" + URLEncoder.encode(filename, "UTF-8"));
            byte[] buffer = new byte[1024];
            int len;
            OutputStream outputStream = response.getOutputStream();
            while ((len = inputStream.read(buffer)) > 0) {
                outputStream.write(buffer, 0, len);
            }
            inputStream.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }

    @GetMapping("/netDownloadLocal")
    public void downloadNet(@RequestParam("netAddress") String netAddress, @RequestParam("filepath") String filepath) {
        try {
            URL url = new URL(netAddress);
            URLConnection conn = url.openConnection();
            InputStream inputStream = conn.getInputStream();
            FileOutputStream fileOutputStream = new FileOutputStream(filepath);
            int byteread;
            byte[] buffer = new byte[1024];
            while ((byteread = inputStream.read(buffer)) != -1) {
                fileOutputStream.write(buffer, 0, byteread);
            }
            fileOutputStream.close();
        } catch (IOException e) {
            throw new RuntimeException(e);
        }
    }