从Android App打开PDF

Question

I am using custom class for opening PDF from my android application. It checks whether PDF is already downloaded and then open PDF using existing PDF Viewer application. If there is no pdf viewer application then it tries to open pdf using google docs.

The class was working fine till the upgrade of Android Studio 2.2.3 to 2.3.2 and Build Tool Version from 24 to 25. The target SDK is still API 24. Unable to figure out exact root cause of the issue.

PDF Class :

public class PDFTools {
private static final String GOOGLE_DRIVE_PDF_READER_PREFIX = "http://docs.google.com/viewer?url=";
private static final String PDF_MIME_TYPE = "application/pdf";
private static final String HTML_MIME_TYPE = "text/html";

/**
 * If a PDF reader is installed, download the PDF file and open it in a reader.
 * Otherwise ask the user if he/she wants to view it in the Google Drive online PDF reader.<br />
 * <br />
 * <b>BEWARE:</b> This method
 * @param context
 * @param pdfUrl
 * @return
 */
public static void showPDFUrl( final Context context, final String pdfUrl ) {
    if ( isPDFSupported( context ) ) {
        downloadAndOpenPDF(context, pdfUrl);
    } else {
        askToOpenPDFThroughGoogleDrive( context, pdfUrl );
    }
}

/**
 * Downloads a PDF with the Android DownloadManager and opens it with an installed PDF reader app.
 * @param context
 * @param pdfUrl
 */

public static void downloadAndOpenPDF(final Context context, final String pdfUrl) {
    // Get filename
    final String filename = pdfUrl.substring( pdfUrl.lastIndexOf( "/" ) + 1 );
    // The place where the downloaded PDF file will be put
    final File tempFile = new File( context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), filename );
    if ( tempFile.exists() ) {
        // If we have downloaded the file before, just go ahead and show it.
        Uri uri = null;
        File docPath = new File(context.getExternalFilesDir(null), "Download");
        File newFile = new File(docPath, filename);

        uri = FileProvider.getUriForFile( context, BuildConfig.APPLICATION_ID + ".provider", newFile );

        openPDF( context, uri);
        return;
    }

    // Show progress dialog while downloading
    final ProgressDialog progress = ProgressDialog.show( context, context.getString( R.string.pdf_show_local_progress_title ),
            context.getString( R.string.message_please_wait ), true );

    // Create the download request
    DownloadManager.Request r = new DownloadManager.Request( Uri.parse( pdfUrl ) );
    r.setDestinationInExternalFilesDir( context, Environment.DIRECTORY_DOWNLOADS, filename );
    final DownloadManager dm = (DownloadManager) context.getSystemService( Context.DOWNLOAD_SERVICE );
    BroadcastReceiver onComplete = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            if ( !progress.isShowing() ) {
                return;
            }
            context.unregisterReceiver( this );

            progress.dismiss();
            long downloadId = intent.getLongExtra( DownloadManager.EXTRA_DOWNLOAD_ID, -1 );
            Cursor c = dm.query( new DownloadManager.Query().setFilterById( downloadId ) );

            if ( c.moveToFirst() ) {
                int status = c.getInt( c.getColumnIndex( DownloadManager.COLUMN_STATUS ) );
                if ( status == DownloadManager.STATUS_SUCCESSFUL ) {
                    Uri uri = null;
                    try {
                        uri = FileProvider.getUriForFile(context, BuildConfig.APPLICATION_ID + ".provider", tempFile );

                    }catch (IllegalArgumentException iae) {
                        iae.printStackTrace();
                    }
                    if (uri !=null) {
                        openPDF(context, uri);
                    }
                }
            }
            c.close();
        }
    };
    context.registerReceiver( onComplete, new IntentFilter( DownloadManager.ACTION_DOWNLOAD_COMPLETE ) );

    // Enqueue the request
    dm.enqueue( r );
}

/**
 * Show a dialog asking the user if he wants to open the PDF through Google Drive
 * @param context
 * @param pdfUrl
 */
public static void askToOpenPDFThroughGoogleDrive( final Context context, final String pdfUrl ) {
    new AlertDialog.Builder( context )
            .setTitle( R.string.pdf_show_online_dialog_title )
            .setMessage( R.string.pdf_show_online_dialog_question )
            .setNegativeButton( R.string.pdf_show_online_dialog_button_no, null )
            .setPositiveButton( R.string.pdf_show_online_dialog_button_yes, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    openPDFThroughGoogleDrive(context, pdfUrl);
                }
            })
            .show();
}

/**
 * Launches a browser to view the PDF through Google Drive
 * @param context
 * @param pdfUrl
 */
public static void openPDFThroughGoogleDrive(final Context context, final String pdfUrl) {
    Intent i = new Intent( Intent.ACTION_VIEW );
    i.setDataAndType(Uri.parse(GOOGLE_DRIVE_PDF_READER_PREFIX + pdfUrl ), HTML_MIME_TYPE );
    context.startActivity( i );
}
/**
 * Open a local PDF file with an installed reader
 * @param context
 * @param localUri
 */
public static final void openPDF(Context context, Uri localUri ) {
    Intent i = new Intent( Intent.ACTION_VIEW );
    i.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
    i.setDataAndType( localUri, PDF_MIME_TYPE );
    context.startActivity( i );
}
/**
 * Checks if any apps are installed that supports reading of PDF files.
 * @param context
 * @return
 */
public static boolean isPDFSupported( Context context ) {
    Intent i = new Intent( Intent.ACTION_VIEW );
    final File tempFile = new File( context.getExternalFilesDir(Environment.DIRECTORY_DOWNLOADS), "test.pdf" );
    i.addFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION);
    i.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION);
    try {
        i.setDataAndType( FileProvider.getUriForFile( context, BuildConfig.APPLICATION_ID + ".provider" ,tempFile ), PDF_MIME_TYPE );
    }catch (IllegalArgumentException iae ) {
    }
    return context.getPackageManager().queryIntentActivities( i, PackageManager.MATCH_DEFAULT_ONLY ).size() > 0;
}

}

It throws an error as

java.lang.IllegalArgumentException: Failed to find configured root that contains /storage/emulated/0/Android/data/<PACKAGE>/files/Download/javascript_pdf_version.pdf

I have taken this sample from stack overflow itself. Appreciate your help on this.

Answer 1

Try something like this to download:

WebService using RestTemplate:

public PdfByteArrayObject getPrintjob(String empId) {
    PdfByteArrayObject pdfByteArrayObject = null;
    try {
        getUrl();
        RestTemplate restTemplate = new RestTemplate();            
        restTemplate.getMessageConverters().add(new MappingJackson2HttpMessageConverter());

        pdfByteArrayObject = restTemplate.getForObject("pdfURL" + empId, PdfByteArrayObject.class);


    } catch (Exception e) {
      e.printStackTrace();            
      Log.e("webser======", e.toString());
    }
    return pdfByteArrayObject;
}

The getUrl method(for File conversion & storage):

public void getUrl() {
    StringBuffer stringBuffer = new StringBuffer();
    String aDataRow = "";
    String aBuffer = "";
    try {
        File serverPath = new File(Environment.getExternalStorageDirectory(), "ServerUrl");

        if (serverPath.exists()) {
            FileInputStream fIn = new FileInputStream(serverPath);
            BufferedReader myReader = new BufferedReader(
                    new InputStreamReader(fIn));

            while ((aDataRow = myReader.readLine()) != null) {
                aBuffer += aDataRow;
            }
            RestUrl = aBuffer;
            Log.e("RestUrl", RestUrl + "--");
            myReader.close();
        } else {
            Log.e("RestUrl", "File not found");
        }

    } catch (IOException e) {
        e.printStackTrace();
    }
    // Toast.makeText(getApplicationContext(),aBuffer,Toast.LENGTH_LONG).show();
}

And the object:

public class PdfByteArrayObject {

private byte[] pdffile;

public byte[] getPdffile() {
    return pdffile;
}

public void setPdffile(byte[] pdffile) {
    this.pdffile = pdffile;
}
}

Hope this helps!