Question

I am using this code and it keeps only getting to the output file line and throws the exception then. Can anyone see what the issue might be with this line?

    try{

        Log.e("Trying","try");
    // Local database
    InputStream input = new FileInputStream("/data/data/package/databases/database");
    Log.e("Input","in");
    // create directory for backup

    // Path to the external backup
    OutputStream output = new FileOutputStream("/sdcard/android/package/databases/mydatabase.db");

    Log.e("Output","out");

    // transfer bytes from the Input File to the Output File
    byte[] buffer = new byte[1024];

    Log.e("Buffer","Buff");
    int length;
    while ((length = input.read(buffer))>0) {
        output.write(buffer, 0, length);
    }

    Log.e("After While","try");
    output.flush();
    output.close();
    input.close();
    } catch (IOException e) {

        throw new Error("Copying Failed");

    }

Answer 1

I doubt this is the cause of your problem, but the following two lines:

    OutputStream output =  new FileOutputStream("/sdcard/android/package/databases/mydatabase.db");
    InputStream input = new FileInputStream("/data/data/package/databases/database");

should be turned into:

    File sdcard = Environment.getExternalStorageDirectory();
    File outputFile = new File(sdcard, "android/package/databases/mydatabase.
    File data = Environment.getDataDirectory();
    File inputFile = new File(data, "data/package/databases/database");

    InputStream input = new FileInputStream(inputFile);
    OutputStream output = new FileOutputStream(outputFile);

This is because the sdcard and data directories may be in different places on different phones. And often, you need to do /mnt/sdcard/ to actually reference the sd card, but the best way is still to use Files and use Environment as I showed above.

You would of course need to put it all into a try block as you already have, and then within the catch, you will need to put e.printStackTrace(); and then if an error is thrown, you can look at the errors from the logcat to determine where your code fails instead of using a log every couple of lines.

And, in your Manifest you have to have the following permission:

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />