Download file using download link in webView android

I want to download a file using a direct download link in my webview. my links are " https://drive.google.com/uc?id=0Bw6vr2LNxB3iUFJrTk5oZDljaTA&export=download ". if I open this link using my default browser then the browser downloads the file automatically. I don't want to open the default web browser, so I want to use the webview. I tried this code:

webView = (WebView) findViewById(R.id.webView1);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.loadUrl(url);
        webView.setDownloadListener(new DownloadListener() {

            @Override
            public void onDownloadStart(String url, String userAgent,
                    String contentDisposition, String mimetype,
                    long contentLength) {
                // TODO Auto-generated method stub
                Toast.makeText(getApplicationContext(), "YES", Toast.LENGTH_SHORT).show();
                Request request = new Request(
                        Uri.parse(url));
                request.allowScanningByMediaScanner();
                request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_HIDDEN);
                request.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "download"); 
                DownloadManager dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
                dm.enqueue(request);   

            }
        });

      

        
        
        
      

    

I put a toast inside setDownloadListener but no toast appears, which means setDownloadListener doesn't work here? Can anyone tell me how to fix the problem? I have a problem with this issue for a long time but cannot solve it.