How to create backup of preferences of my app and keep it even if uninstall - Mode offline

Question

I want have a backup on my phone, in mode OFFLINE, of my preferences, guaranteed that this preferences keep once that the app was uninstalled!!

If someone can send me a good tutorial or explicit step I will thank you!

Answer 1

Sorry, but this is not possible. The only places that you can write files that survive an uninstall are places where the user can delete those files.

Answer 2

Solution 1:

https://stackoverflow.com/a/11135800/3750554

To reiterate what the above link says, you can use the following code to copy a folder on Android:

// If targetLocation does not exist, it will be created.
public void copyDirectory(File sourceLocation , File targetLocation)
throws IOException {

    if (sourceLocation.isDirectory()) {
        if (!targetLocation.exists() && !targetLocation.mkdirs()) {
            throw new IOException("Cannot create dir " + targetLocation.getAbsolutePath());
        }

        String[] children = sourceLocation.list();
        for (int i=0; i<children.length; i++) {
            copyDirectory(new File(sourceLocation, children[i]),
                    new File(targetLocation, children[i]));
        }
    } else {

        // make sure the directory we plan to store the recording in exists
        File directory = targetLocation.getParentFile();
        if (directory != null && !directory.exists() && !directory.mkdirs()) {
            throw new IOException("Cannot create dir " + directory.getAbsolutePath());
        }

        InputStream in = new FileInputStream(sourceLocation);
        OutputStream out = new FileOutputStream(targetLocation);

        // Copy the bits from instream to outstream
        byte[] buf = new byte[1024];
        int len;
        while ((len = in.read(buf)) > 0) {
            out.write(buf, 0, len);
        }
        in.close();
        out.close();
    }
}

I assume that you want an app to be backed up. You can copy its location in /data/data to wherever you choose to backup.

Solution 2:

Alternatively, if you have a terminal emulator (if you don't, there are several on the Google Play store), you can do the POSIX way of doing it and use cp.

cp -r /data/data/<app> <backup location>

However, CommonsWare is right. No matter where you copy your things, the user will be able to delete them.