ZipOutputStream zip = null;
try {
connection = dataSource.getConnection();
IVirtualFile storage = BackupUtil.rotate(this.storageDirectory, "backup", "dat", 20);
storage.setIOHandler( new EncryptionIOHandler(provider) );
zip = new ZipOutputStream(storage.getOutputStream());
PrintWriter writer = new PrintWriter(zip, true);
for (EncryptedTable table : getEncryptedTables(connection)) {