Android open pdf file

The problem is that there is no app installed to handle opening the PDF. You should use the Intent Chooser, like so:

File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath() +"/"+ filename);Intent target = new Intent(Intent.ACTION_VIEW);target.setDataAndType(Uri.fromFile(file),"application/pdf");target.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);Intent intent = Intent.createChooser(target, "Open File");try {    startActivity(intent);} catch (ActivityNotFoundException e) {    // Instruct the user to install a PDF reader here, or something}   

As of API 24, sending a file:// URI to another app will throw a FileUriExposedException. Instead, use FileProvider to send a content:// URI:

public File getFile(Context context, String fileName) {    if (!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)) {        return null;    }    File storageDir = context.getExternalFilesDir(null);    return new File(storageDir, fileName);}public Uri getFileUri(Context context, String fileName) {    File file = getFile(context, fileName);    return FileProvider.getUriForFile(context, BuildConfig.APPLICATION_ID + ".provider", file);}

You must also define the FileProvider in your manifest:

<provider    android:name="android.support.v4.content.FileProvider"    android:authorities="com.mydomain.fileprovider"    android:exported="false"    android:grantUriPermissions="true">    <meta-data        android:name="android.support.FILE_PROVIDER_PATHS"        android:resource="@xml/file_paths" /></provider>

Example file_paths.xml:

<?xml version="1.0" encoding="utf-8"?><paths xmlns:android="http://schemas.android.com/apk/res/android">    <external-files-path name="name" path="path" /></paths>

Replace "name" and "path" as appropriate.

To give the PDF viewer access to the file, you also have to add the FLAG_GRANT_READ_URI_PERMISSION flag to the intent:

private void displayPdf(String fileName) {    Uri uri = getFileUri(this, fileName);    Intent intent = new Intent(Intent.ACTION_VIEW);    intent.setDataAndType(uri, "application/pdf");    // FLAG_GRANT_READ_URI_PERMISSION is needed on API 24+ so the activity opening the file can read it    intent.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY | Intent.FLAG_GRANT_READ_URI_PERMISSION);    if (intent.resolveActivity(getPackageManager()) == null) {        // Show an error    } else {        startActivity(intent);    }}

See the FileProvider documentation for more details.

String dir="/Attendancesystem"; public void displaypdf() {        File file = null;            file = new File(Environment.getExternalStorageDirectory()+dir+ "/sample.pdf");        Toast.makeText(getApplicationContext(), file.toString() , Toast.LENGTH_LONG).show();        if(file.exists()) {            Intent target = new Intent(Intent.ACTION_VIEW);            target.setDataAndType(Uri.fromFile(file), "application/pdf");            target.setFlags(Intent.FLAG_ACTIVITY_NO_HISTORY);            Intent intent = Intent.createChooser(target, "Open File");            try {                startActivity(intent);            } catch (ActivityNotFoundException e) {                // Instruct the user to install a PDF reader here, or something            }        }        else            Toast.makeText(getApplicationContext(), "File path is incorrect." , Toast.LENGTH_LONG).show();    }