android - 如何从我的 android webview 下载由 Tcpdf 生成的 pdf

Question

需要帮助来解决我的问题。在我的 android webview 中，使用tcpdf生成的 pdf无法正常工作......它在 pdf 中生成了一些垃圾值

//下载文件 myWebView.setDownloadListener(new DownloadListener() { @Override public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {

            DownloadManager.Request myRequest = new DownloadManager.Request(Uri.parse(url));
            myRequest.allowScanningByMediaScanner();
            myRequest.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
            //new

            myRequest.setDestinationInExternalPublicDir(Environment.DIRECTORY_DOWNLOADS, "download");


            //create download manager
            DownloadManager myManager = (DownloadManager) getSystemService(DOWNLOAD_SERVICE);

            myManager.enqueue(myRequest);

            Toast.makeText(MainActivity.this, "Downloding file....", Toast.LENGTH_SHORT).show();


        }
    });

    //TCPDF

    myWebView.setDownloadListener(new DownloadListener() {
        @Override
        public void onDownloadStart(String url, String userAgent, String contentDisposition, String mimetype, long contentLength) {
            //start download
            DownloadPDF downlooadPDF = new DownloadPDF();
            downlooadPDF.execute(url, userAgent, contentDisposition);

            //Toast.makeText(MainActivity.this, "Downloding ...", Toast.LENGTH_SHORT).show();
        }
    });

}


//TCPDF

private class DownloadPDF extends AsyncTask<String, Integer, String> {
    @Override
    protected String doInBackground(String... sUrl) {
        try {
            URL url = new URL(sUrl[0]);

            File myDir = new File(Environment.getExternalStoragePublicDirectory(
                    Environment.DIRECTORY_DOWNLOADS).toString() + "/myPDF");

            // create the directory if it does not exist
            if (!myDir.exists()) myDir.mkdirs();

            HttpURLConnection connection = (HttpURLConnection) url.openConnection();
            connection.setDoOutput(true);
            connection.connect();

            //get filename from the contentDisposition
            String filename = null;
            Pattern p = Pattern.compile("\"([^\"]*)\"");
            Matcher m = p.matcher(sUrl[2]);
            while (m.find()) {
                filename = m.group(1);
            }

            File outputFile = new File(myDir, filename);

            InputStream input = new BufferedInputStream(connection.getInputStream());
            OutputStream output = new FileOutputStream(outputFile);

            byte data[] = new byte[1024];
            long total = 0;
            int count;
            while ((count = input.read(data)) != -1) {
                total += count;
                output.write(data, 0, count);
            }
            connection.disconnect();
            output.flush();
            output.close();
            input.close();

            displayPdf(); // a function to open the PDF file automatically

        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    private void displayPdf() {
        try {

            Object filename = fileList();
            File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + "/myPDF/" + filename);




            Intent intent = new Intent();
            intent.setAction(Intent.ACTION_VIEW);
            Uri uri = Uri.fromFile(file);
            intent.setDataAndType(uri, "application/pdf");
            startActivity(intent);
        } catch (Exception e) {
            Log.i("TAG", e.getMessage());
        }
    }

}