Unable to read file from sd card in Android

Question

I am trying to read a file from sdcard using the following code

     f = new RandomAccessFile("/storage/sdcard0/trac.txt", "r");

But the app crashes while doing so. I am able to create and write a file in sdcard but unable to read it. I have following permissions in my manifest and i am running it as a system app:

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_LOGS" />
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
<uses-permission android:name="android.permission.WRITE_MEDIA_STORAGE"/>
<uses-permission android:name="android.permission.READ_MEDIA_STORAGE"/>
<uses-permission android:name="android.permission.ACCESS_SUPERUSER"></uses-permission>
<uses-permission android:name="android.permission.INJECT_EVENTS"></uses-permission>

Answer 1

Try getting your sd card path by doing this:

String yourpath = Environment.getExternalStorageDirectory()
                             .getAbsolutePath() + "/folderName/";

Answer 2

try {
                File myFile = new File("/sdcard/mysdfile.txt");
                FileInputStream fIn = new FileInputStream(myFile);
                BufferedReader myReader = new BufferedReader(
                        new InputStreamReader(fIn));
                String fileStr= "";
                String aBuffer = "";
                while ((fileStr= myReader.readLine()) != null) {
                    aBuffer += fileStr+ "\n";
                }
                txtData.setText(aBuffer);
                myReader.close();
                Toast.makeText(getBaseContext(),
                        "Done reading SD 'mysdfile.txt'",
                        Toast.LENGTH_SHORT).show();
            } catch (Exception e) {
                Toast.makeText(getBaseContext(), e.getMessage(),
                        Toast.LENGTH_SHORT).show();
            }

Its helpful for me. To more detail :

How to read a selected text file from sdcard on android