is it possible backup and RESTORE a database file

问题:

This question already has an answer here:

• Backup and restore SQLite database to sdcard 4 answers

in my app I need get a backup of my database, but after I'll need restore it again,

i have read somethings, but i do not sure if this is necessary to have a rooted device, i need backup/restore the all data in non root devices, is it possible?

my first idea was creating a txt file for write the select, and later insert it again.

but i believe this is much "problem" then i don't know if this is possible copy the database and paste in sd card for backup, and copy from sd card and paste in path of database for restore for non root devices.

回答1:

Here is some code to make it work

private void importDB() {
        try {
            File sd = Environment.getExternalStorageDirectory();
            File data = Environment.getDataDirectory();
                if (sd.canWrite()) {
                String currentDBPath = "//data//" + "<package name>"
                        + "//databases//" + "<database name>";
                String backupDBPath = "<backup db filename>"; // From SD directory.
                File backupDB = new File(data, currentDBPath);
                File currentDB = new File(sd, backupDBPath);

            FileChannel src = new FileInputStream(backupDB).getChannel();
            FileChannel dst = new FileOutputStream(currentDB).getChannel();
            dst.transferFrom(src, 0, src.size());
            src.close();
            dst.close();
            Toast.makeText(getApplicationContext(), "Import Successful!",
                    Toast.LENGTH_SHORT).show();

        }
    } catch (Exception e) {

        Toast.makeText(getApplicationContext(), "Import Failed!", Toast.LENGTH_SHORT)
                .show();

    }
}

private void exportDB() {
    try {
        File sd = Environment.getExternalStorageDirectory();
        File data = Environment.getDataDirectory();

        if (sd.canWrite()) {
            String currentDBPath = "//data//" + "<package name>"
                    + "//databases//" + "<db name>";
            String backupDBPath = "<destination>";
            File currentDB = new File(data, currentDBPath);
            File backupDB = new File(sd, backupDBPath);

            FileChannel src = new FileInputStream(currentDB).getChannel();
            FileChannel dst = new FileOutputStream(backupDB).getChannel();
            dst.transferFrom(src, 0, src.size());
            src.close();
            dst.close();
            Toast.makeText(getApplicationContext(), "Backup Successful!",
                    Toast.LENGTH_SHORT).show();

        }
    } catch (Exception e) {

        Toast.makeText(getApplicationContext(), "Backup Failed!", Toast.LENGTH_SHORT)
                .show();

    }
}