Method of calling system download in Android in WebView

Preface

Recently found in the project WebView loading download page is a blank, there is no download, so simply call the system download to download it.

Process

Customize a download monitor to realize the interface of DownloadListener

class MyDownloadStart implements DownloadListener{
  @Override
  public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {
   downUrl = url;
   // Get the file name from the link 
   String dirNameString = url.substring(url.lastIndexOf("/") + 1);
   // Get the size of the downloaded file 
   DecimalFormat decimalFormat = new DecimalFormat("0.00");
   float size = contentLength;
   dirName.setText(dirNameString);
   if (size < 1024){
    dirSize.setText(size + "B");
   }else if (size < 1048576){
    String dirSizeStringKB = decimalFormat.format(size / 1024);
    dirSize.setText(dirSizeStringKB + "K");
   }else if (size < 1073741824){
    String dirSizeString = decimalFormat.format(size / 1048576);
    dirSize.setText(dirSizeString + "M");
   }else {
    String dirStringG = decimalFormat.format(size / 1073741824);
    dirSize.setText(dirStringG + "G");
   }
   // Displays whether to download or not dialog
   downdialog.show();
  }
}

Set MyDownloadStart to WebView;

mWebView.setWebViewDownListener(new MyDownloadStart());

Set Dialog, click Yes to call the system to download

DownloadManager downloadManager = (DownloadManager) getContext().getSystemService(Context.DOWNLOAD_SERVICE);
DownloadManager.Request request = new DownloadManager.Request(Uri.parse(downUrl));
// When downloading, display notification after downloading 
request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
// Download path, the 1 The parameter is the folder name, the 2 The parameter is the name of the downloaded file 
request.setDestinationInExternalPublicDir("SooDown",dirName.getText().toString());
request.setVisibleInDownloadsUi(true);
downloadManager.enqueue(request);

So you can download it, but we don't know when it will be finished. After downloading through DownloadManager, the system will send a broadcast. What we have to do is to receive the broadcast and process it

public class DownloadReceiver extends BroadcastReceiver{


 @Override
 public void onReceive(Context context, Intent intent) {
  DownloadManager manager = (DownloadManager) context.getSystemService(Context.DOWNLOAD_SERVICE);
  if (DownloadManager.ACTION_DOWNLOAD_COMPLETE.equals(intent.getAction())){
   Toast.makeText(context," Download complete ",Toast.LENGTH_SHORT).show();
  }else if (DownloadManager.ACTION_NOTIFICATION_CLICKED.equals(intent.getAction())){
   // Click on the notification bar to enter the download management page 
   Intent intent1 = new Intent(DownloadManager.ACTION_VIEW_DOWNLOADS);
   intent1.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
   context.startActivity(intent1);
  }
 }
}

In the last step, don't forget to configure BroadcastReceiver

Configured in AndroidManifest. xml

<receiver android:name=".Utils.DownloadReceiver">
   <intent-filter>
    <action android:name="android.intent.action.DOWNLOAD_COMPLETE"/>
    <action android:name="android.intent.action.DOWNLOAD_NOTIFICATION_CLICKED"/>
   </intent-filter>
</receiver>

In this way, it is almost ok.