Android WebView 无法在 UIDAI/Aadhaar 网站上的 DownloadStart 上下载文件

Question

我正在使用 Webview 从 UIDAI 网站下载我的应用程序中的 .zip 文件。
但是当 DownloadListener 被调用时
它返回正确的数据，但下载该 .zip 文件中的 HTML 网页，而不是下载实际文件。
而当我尝试通过 chrome 下载相同的 zip 文件时。它正在下载正确的 zip 文件。
请帮我解决这个问题。为什么在这个特定网站( https://resident.uidai.gov.in/offline-kyc )的 webview 中会发生这种情况，而使用相同的下载监听器我可以在其他网站上下载文件？

我的代码:

public class wvDownloadFile extends AppCompatActivity {

private static final int MY_PERMISSION_REQUEST_CODE = 123;
String QT_TAG = "download test";

String fileName = "test";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    WebView wv = findViewById(R.id.web_view);

    checkPermission();
    String url = "https://resident.uidai.gov.in/offline-kyc";
    wv.loadUrl(url);
    wv.getSettings().setJavaScriptEnabled(true);
    wv.getSettings().setSupportMultipleWindows(true);
    wv.getSettings().setAllowContentAccess(true);
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
        wv.getSettings().setAllowUniversalAccessFromFileURLs(true);
    }

    wv.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
    wv.getSettings().setBuiltInZoomControls(false);
    wv.getSettings().setJavaScriptEnabled(true);
    wv.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
    wv.getSettings().setAllowFileAccess(true);
    wv.getSettings().setAllowContentAccess(true);
    wv.getSettings().setAllowFileAccess(true);
    wv.getSettings().setAllowFileAccessFromFileURLs(true);
    wv.getSettings().setAllowUniversalAccessFromFileURLs(true);
    wv.getSettings().setDomStorageEnabled(true);

    // userAgent:  downloadlistener: Mozilla/5.0 (Linux; Android 7.1.2; Redmi Y1 Lite Build/N2G47H; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/76.0.3809.132 Mobile Safari/537.36
    // mimeType: application/zip
    // contentLength: 5445
    // contentDispostition: attachment; filename=offlineaadhaar20190925055612130.zip
    // url: https://resident.uidai.gov.in/offline-kyc

    wv.setDownloadListener(new DownloadListener() {
        @Override
        public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimeType, long contentLength) {


            fileName = URLUtil.guessFileName(url, contentDisposition, mimeType);

            Log.i(QT_TAG, "downloadlistener0: " + userAgent + " " + mimeType + " " + contentLength + " " + contentDisposition + " " + url);
            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);
            dm.enqueue(request);
            Toast.makeText(getApplicationContext(), "Downloading File0 ", Toast.LENGTH_LONG).show();
        }
    });

    wv.setWebViewClient(new WebViewClient() {

        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            Log.i(QT_TAG, "listener  overide url ");
            view.loadUrl(url);
            return true;
        }
    });
}

protected void checkPermission() {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            if (shouldShowRequestPermissionRationale(Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                // show an alert dialog
                AlertDialog.Builder builder = new AlertDialog.Builder(wvDownloadFile.this);
                builder.setMessage("Write external storage permission is required.");
                builder.setTitle("Please grant permission");
                builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        ActivityCompat.requestPermissions(
                                wvDownloadFile.this,
                                new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                                MY_PERMISSION_REQUEST_CODE
                        );
                    }
                });
                builder.setNeutralButton("Cancel", null);
                AlertDialog dialog = builder.create();
                dialog.show();
            } else {
                // Request permission
                ActivityCompat.requestPermissions(
                        wvDownloadFile.this,
                        new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                        MY_PERMISSION_REQUEST_CODE
                );
            }
        } else {
            // Permission already granted
        }
    }
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSION_REQUEST_CODE: {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // Permission granted
            } else {
                // Permission denied
            }
        }
    }
}

}

Answer 1

问题是我们没有从 downloadListener 获取从 web View 到 downloadManager 的链接

wv.setDownloadListener(new DownloadListener() {

    @Override
    public void onDownloadStart(String url, String userAgent, 
                       String contentDisposition, String mimeType, long contentLength) {

             Log.d(TAG, "onDownloadStart: " + url); // taking debug log

    }

结果将是，url = https://resident.uidai.gov.in/offline-kyc .由于 cookie session (出于 UIDAI 的安全原因)，这不是文件的下载链接。故障不是来自 downloadManager，故障是 OnDownloadListener 没有使用 cookie session 获取链接。
我必须这样做，所以这是另一种方法，

二手 chromeCustomTabs Link

用户下载 zip 文件后，我告诉他们分享共享代码。

之后，使用包含“offlineaadhaar”和“zip”

的 string.compareTo 方法找到最新(按字母顺序排列)下载的文件

之后使用共享代码解压缩并创建同名文件夹

从该文件夹中获取 XML 文件的路径

解析 XML，然后将其用于您的任务

如果有人使用 webView 找到解决方案，请分享