createdb();$db->conn();echo '
';//连接sqlite$fact = new sqlitefactory();$db = $fact->createdb();$db->conn();echo '
';/** * 扩展：添加oracle连接 */class oracledb implements db{ function conn() { echo '连接上oracle....'; }}class oraclefactory implements factory{ public function createdb() { return new oracledb(); }}//连接oracle$fact = new oraclefactory();$db = $fact->createdb();$db->conn();echo '
';