~~~ <?php interface Db{ function conn(); } class DbMysql implements Db { function conn(){ return "mysql conn"; } } class DbSqlite implements Db{ function conn(){ return "sqlite conn"; } } interface Factory{ function createDB(); } class mysqlFactory implements Factory{ function createDB(){ return new DbMysql(); } } class sqliteFactory implements Factory{ function createDB(){ return new DbSqlite(); } } //调用 $mysqlFactory = new mysqlFactory(); echo $mysqlFactory->createDB()->conn(); $sqliteFactory = new sqliteFactory(); echo $sqliteFactory->createDB()->conn(); ~~~