Java 如何在android 10或更高版本的webview中下载.pdf文件

`我正在开发一个webview应用程序，它在安卓10上下载.bin文件，我在安卓9上测试了该应用程序，它正常工作。我是android开发新手。

您可以使用HTTP客户端API（如OkHttp）下载PDF。

webView = findViewById(R.id.webView);
        webView.loadUrl(url);

        webView.getSettings().setAllowFileAccess(true);
        webView.getSettings().setAppCacheEnabled(true);
        webView.setWebViewClient(new WebViewClient());
        webView.setWebChromeClient(new WebChromeClient());
        webView.getSettings().setJavaScriptEnabled(true);
        webView.getSettings().supportMultipleWindows();
        webView.getSettings().setSupportMultipleWindows(true);
        webView.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
        webView.getSettings().setAllowFileAccess(true);
        webView.getSettings().setBuiltInZoomControls(true);
        webView.getSettings().setDisplayZoomControls(false);


        webView.setDownloadListener(new DownloadListener()
        {
            @Override
            public void onDownloadStart(String url, String userAgent,
                                        String contentDisposition, String mimeType,
                                        long contentLength) {
                DownloadManager.Request request = new DownloadManager.Request(
                        Uri.parse(url));
                request.setMimeType(mimeType);
                String cookies = CookieManager.getInstance().getCookie(url);
                request.addRequestHeader("cookie", cookies);
                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 File", Toast.LENGTH_LONG).show();
            }});