如何使用WebView和WebClient for Android管理「病毒警告」警報頁面？

Question

由於谷歌驅動器無法下載超過25 MB的文件，因爲它要求從HTML頁面授權用戶，所以我認爲有必要讓這些文件在webView中顯示「病毒警告」頁面我的應用程序所以我在Android studio中創建了這個小樣本進行測試。這是很簡單的一個MainActivity和包含一個簡單的WebView的activity.xml：

public class MainActivity extends AppCompatActivity { 
private static final int WRITE_SDCARD_REQUEST_CODE = 12; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    // permission to write file on internal storage .... 
    if (ContextCompat.checkSelfPermission(MainActivity.this, 
      Manifest.permission.WRITE_EXTERNAL_STORAGE) 
      != PackageManager.PERMISSION_GRANTED) { 

     if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, 
       Manifest.permission.WRITE_EXTERNAL_STORAGE)) { 

      ActivityCompat.requestPermissions(MainActivity.this, 
        new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 
        WRITE_SDCARD_REQUEST_CODE); 

     } else { 
      ActivityCompat.requestPermissions(MainActivity.this, 
        new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 
        WRITE_SDCARD_REQUEST_CODE); 

     } 
    } 
    else { 
     // launch my webPage and webClient withe the given url of my file 
     WebView myWebView = (WebView) findViewById(R.id.webview); 
     myWebView.loadUrl("https://drive.google.com/uc?export=download&id=0B4fwFC8FCSQGGTZfbHYwczBXVjg"); 
     myWebView.setWebViewClient(new MyWebViewClient()); 
    } 


} 

private class MyWebViewClient extends WebViewClient { 
    @Override 
    public boolean shouldOverrideUrlLoading(WebView view, String url) { 
     // return after valid with "Download anyway " button 
     Log.i("URL",url);//<-- url result: https://drive.google.com/uc?export=download&confirm=LoXi&id=0B4fwFC8FCSQGGTZfbHYwczBXVjg 
     //with "confirm=LoXi" Added to the original link 

     // so i try to download this new confirmed url given by Google Drive warning page 
     // But the link is not valid for download!!!!! Why???? 
     DownloadFileFromURL dFURL = new DownloadFileFromURL(); 
     dFURL.execute(url); 
     // I obtain a wrong file .... 36 Ko...not good! 
     return true; 
    } 
} 

@Override 
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { 
    super.onRequestPermissionsResult(requestCode, permissions, grantResults); 

    if (requestCode == WRITE_SDCARD_REQUEST_CODE) 
    if (grantResults.length > 0 
      && grantResults[0] == PackageManager.PERMISSION_GRANTED) { 
     WebView myWebView = (WebView) findViewById(R.id.webview); 
     // original link of file Google drive that i want to download 
     myWebView.loadUrl("https://drive.google.com/uc?export=download&id=0B4fwFC8FCSQXbTZfbHYwczBXVjg"); 
     myWebView.setWebViewClient(new MyWebViewClient()); 
    } 

} 


class DownloadFileFromURL extends AsyncTask<String, String, String> { 

    /** 
    * Before starting background thread Show Progress Bar Dialog 
    * */ 
    @Override 
    protected void onPreExecute() { 
     super.onPreExecute(); 
    } 

    /** 
    * Downloading file in background thread 
    * */ 
    @Override 
    protected String doInBackground(String... f_url) { 
     int count; 
     try { 
      URL url = new URL(f_url[0]); 
      URLConnection conection = url.openConnection(); 
      conection.connect(); 

      // this will be useful so that you can show a tipical 0-100% 
      // progress bar 
      int lenghtOfFile = conection.getContentLength(); 

      // download the file 
      InputStream input = new BufferedInputStream(url.openStream(), 
        8192); 

      // Output stream 
      OutputStream output = new FileOutputStream(Environment 
        .getExternalStorageDirectory().toString() 
        + "/video.mp4"); 

      byte data[] = new byte[1024]; 

      long total = 0; 

      while ((count = input.read(data)) != -1) { 
       total += count; 
       // publishing the progress.... 
       // After this onProgressUpdate will be called 
       publishProgress("" + (int) ((total * 100)/lenghtOfFile)); 

       // writing data to file 
       output.write(data, 0, count); 
      } 

      // flushing output 
      output.flush(); 

      // closing streams 
      output.close(); 
      input.close(); 

     } catch (Exception e) { 
      Log.e("Error: ", e.getMessage()); 
     } 

     return null; 
    } 

    /** 
    * Updating progress bar 
    * */ 
    protected void onProgressUpdate(String... progress) { 
     // setting progress percentage 
     //pDialog.setProgress(Integer.parseInt(progress[0])); 
    } 

    /** 
    * After completing background task Dismiss the progress dialog 
    * **/ 
    @Override 
    protected void onPostExecute(String file_url) { 
     // dismiss the dialog after the file was downloaded 
     //dismissDialog(progress_bar_type); 
    } 

} 

}

從我的超過25 MB（在這裏90莫）我也顯示頁面文件的下載鏈接驅動器的「病毒警告」。點擊下載按鈕「無論如何下載」後，我可以在我的WebClient中獲得修改的鏈接。但是這個鏈接似乎並不正確。如果我嘗試複製/粘貼它在鉻我回到「病毒警告」的同一頁！爲什麼？？

當我右鍵單擊「下載任何」按鈕來複制鏈接時，該鏈接與我通過WebClient獲得的形式相同，但是「confirm = XXXX」部分不是，並且它可以訪問下載！

你能給我你的意見和建議嗎？

謝謝。

Answer 1

我終於在我的WebViewClient管理cookies和使用下載管理器解決了這個問題：``

private class MyWebViewClient extends WebViewClient { 
    @Override 
    public boolean shouldOverrideUrlLoading(WebView view, String url) { 
     // prevent other actions on page 
     if (url.contains("export=download&confirm")){ 
      DownloadManager manager = (DownloadManager) getSystemService(Context.DOWNLOAD_SERVICE); 
      Uri source = Uri.parse(url); 
      DownloadManager.Request request = new DownloadManager.Request(source); 
      String cookie = CookieManager.getInstance().getCookie(url); 
      request.addRequestHeader("Cookie", cookie); 
      request.addRequestHeader("User-Agent", view.getSettings().getUserAgentString()); 
      request.addRequestHeader("Accept", "text/html, application/xhtml+xml, *" + "/" + "*"); 
      request.addRequestHeader("Accept-Language", "en-US,en;q=0.7,he;q=0.3"); 
      request.addRequestHeader("Referer", url); 
      request.setDestinationInExternalPublicDir("/","video.mp4"); 
      manager.enqueue(request); 
     }else { 
      // a keyEvent back listener should be implemented 
      myWebView.loadUrl(url); 
     } 

     return true; 
    } 
    @Override 
    public void onPageFinished(WebView view, String url){ 

    } 
} 

我希望這將有助於。