Android：下載文件八位字節流 web 查看

Question

我希望能夠通過 Android 的 webview 下載文件，但我做不到。

我必須下載的 url 格式如下：

http://{server_path}/Download?mimetype=application/octet-stream

我正在使用這段代碼：

myWebView.setDownloadListener(new DownloadListener() {
  public void onDownloadStart(String url, String userAgent,
                              String contentDisposition, String mimetype,
                              long contentLength) {
    DownloadManager.Request request = new DownloadManager.Request(Uri.parse(url));

    request.setMimeType(mimetype);
    //------------------------COOKIE!!------------------------
    String cookies = CookieManager.getInstance().getCookie(url);
    request.addRequestHeader("cookie", cookies);
    //------------------------COOKIE!!------------------------
    request.addRequestHeader("User-Agent", userAgent);
    request.setDescription("Downloading file...");
    request.setTitle(URLUtil.guessFileName(url, contentDisposition, mimetype));
    request.allowScanningByMediaScanner();
    request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
    request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, URLUtil.guessFileName(url, contentDisposition, mimetype));
    DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
    long donwloadedFileId = dm.enqueue(request);
    String downloadedMimeType = dm.getMimeTypeForDownloadedFile(donwloadedFileId)
    Toast.makeText(getApplicationContext(), "Downloading File", Toast.LENGTH_LONG).show();
  }
});

當我嘗試下載時，我得到的只是一個“download.bin”文件。

當我檢查 function URLUtil.guessFileName(url, contentDisposition, mimetype)時，將其作為文件名返回。

你可以幫幫我嗎？

編輯

如果我從 Android 文件管理器應用程序重命名下載的文件，它會成功打開。 所以也許答案是如何設置下載文件的正確 mimeType？

編輯 2 (13/4/20)

另外我忘了提到在上面的代碼中 mimeType 是“application/octet-stream”

Answer 1

您可以嘗試對您的文件執行此操作：

File file = new File(yourFileHere);
mimeType= URLConnection.guessContentTypeFromName(file.getName());

或嘗試

Files.probeContentType(path)

編輯

將下一個 header 添加到您的請求中：

"content-disposition", "attachment; filename=\"" + fileName +"\""

Answer 2

@Net這里是調試output：

this = {MainActivity$1@10423} 
url = "http://{server_path}/Download?mimetype=application/octet-stream"
userAgent = "Mozilla/5.0 (Linux; Android 10; Android SDK built for x86 Build/QSR1.191030.002; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/74.0.3729.185 Mobile Safari/537.36"
contentDisposition = "attachment; filename*=UTF-8''M1FBACTFMB9F.pdf"
mimetype = "application/octet-stream"
contentLength = 192748
request = {DownloadManager$Request@10430} 
dm = {DownloadManager@10432}