安卓将应用程序包\\data\\com.android.pcr\\databases\\vrp_db中的Sqlite数据库复制到SD卡文件夹备份

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

String state = Environment.getExternalStorageState();
if (Environment.MEDIA_MOUNTED.equals(state)) {
    // SD卡可用
} else {
    // SD卡不可用
}

File backupDir = new File(Environment.getExternalStorageDirectory(), "backup_folder");
if (!backupDir.exists()) {
    backupDir.mkdirs();
}

File dbFile = getDatabasePath("vrp_db");
File backupFile = new File(backupDir, "vrp_db_backup.db");

try {
    FileInputStream fis = new FileInputStream(dbFile);
    FileOutputStream fos = new FileOutputStream(backupFile);
    byte[] buffer = new byte[1024];
    int length;
    while ((length = fis.read(buffer)) > 0) {
        fos.write(buffer, 0, length);
    }
    fos.flush();
    fos.close();
    fis.close();
} catch (IOException e) {
    e.printStackTrace();
}