As the operations offered by the classes are the same, you can use an interface to define a contract that all of your classes implement.

由于这些类提供的操作相同，您可以使用一个接口来定义一个所有类实现的协定。

youdao

Under the contract, Questronix would implement a full database package using DB2 version 8 and an SAP business application.

依据合同，Questronix将用DB 2 v8和SAP的商业应用程序实现一个完全的数据库包。

youdao

Applications can then use the DiscoveryClient API to find services that implement a given contract.

然后应用程序就可以使用DiscoveryClient API来寻找实现特定contract的服务。

youdao

Pre-Sal Petroleo would also run a new contract system that allows the state to implement production-sharing agreements that would direct more of the oil windfall to the state than to the oil companies whenever the price of oil goes up.

FORBES: Brazil: Strategic Planning For Pre-Salt