如何从WebView下载图像并将其保存在外部存储中？

Question

1. 我想通过长按图像从Webview下载sdCard中的图像。

2. 我想通过长按图像共享图像，而不像chrome那样将图像存储在sdCard中。 我可以下载图像，但是它们没有保存在sdCard中。 我几乎在整个网络上搜索，但没有任何解决方案。

   public class MainActivity extends AppCompatActivity {
   
   WebView webView;
   String HTTP_URL = "https://www.google.com" ;
   private long downloadID ;
   Bitmap bitmap;
   Tag TAG;
   
   @Override
   protected void onCreate(Bundle savedInstanceState) {
   super.onCreate(savedInstanceState);
   setContentView(R.layout.activity_main);
   
   webView = (WebView)findViewById(R.id.myWebView);
   webView.getSettings().setJavaScriptEnabled(true);
   webView.setWebViewClient(new WebViewClient());
   webView.getSettings().setDomStorageEnabled(true);
   
   registerForContextMenu(webView);
   webView.loadUrl(HTTP_URL);
   
   @Override
   public void onCreateContextMenu(ContextMenu contextMenu, View view,
   ContextMenu.ContextMenuInfo contextMenuInfo){
   super.onCreateContextMenu(contextMenu, view, contextMenuInfo);
   
   final WebView.HitTestResult webViewHitTestResult = webView.getHitTestResult();
   
   if (webViewHitTestResult.getType() == WebView.HitTestResult.IMAGE_TYPE ||
   webViewHitTestResult.getType() == WebView.HitTestResult.SRC_IMAGE_ANCHOR_TYPE) {
   
   contextMenu.setHeaderTitle("Select option");
   
   
   contextMenu.add(0, 1, 0, "Download Image")
   .setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() {
   @Override
   public boolean onMenuItemClick(MenuItem menuItem) {
   
   String DownloadImageURL = webViewHitTestResult.getExtra();
   
   if(URLUtil.isValidUrl(DownloadImageURL)){
   
   DownloadManager.Request request = new DownloadManager.Request(Uri.parse(DownloadImageURL));
   request.allowScanningByMediaScanner();
   
   
   request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
   DownloadManager downloadManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);
   downloadID = downloadManager.enqueue(request);
   String publicDirPath = ExternalStorageUtil.getPublicExternalStorageBaseDir("/");
   File newFile = new File(publicDirPath, "download");
   newFile.mkdirs();
   
   File newFile1 = new File(newFile, "image.png");
   OutputStream os;
   
   try {
   os = new FileOutputStream(newFile1);
   bitmap.compress(Bitmap.CompressFormat.PNG, 100, os);
   os.flush();
   os.close();
   } catch (FileNotFoundException e) {
   e.printStackTrace();
   } catch (IOException e) {
   e.printStackTrace();
   }
   
   } return false;
   }
   
   
   
   //set Download Listener
   
   webView.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.allowScanningByMediaScanner();
   
   request.setNotificationVisibility(
   DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
   
   request.setDestinationInExternalPublicDir("timestop", "Tillem");
   
   DownloadManager dm = (DownloadManager) getSystemService(
   DOWNLOAD_SERVICE);
   
   dm.enqueue(request);
   
   
   }});
   }}