单项选择题

下面可提供安全电子邮件服务的是(67)

A.RSA
B.SS
C.SET
D.S/MIME
热门 试题

未分类题
某灯具厂商欲生产一个灯具遥控器,该遥控器具有7个可编程的插槽,每个插槽都有开关灯具的开关,现采用Command(命令)模式实现该遥控器的软件部分。Command模式的类图如图6-1所示。【Java代码】class Light{public Light( ){}public Light(String name){ *代码省略* }public void on( ){ *代码省略* } 开灯public void off( ){ *代码省略* } 关灯 其余代码省略}(1){public void execute( );}class LightOnCommand implements Command{ 开灯命令Light light;public LightOnCommand(Light light){this.light=light;}public void execute( ){(2);}}class LightOffCommand implements Command{ 关灯命令Light light;public LightOffCommand(Light light){this.light=light;}public void execute( ){(3);}}class RemoteControl{ 遥控器Command[]onCommands=new Command[7];Command[]offCommands=new Command[7];public RemoteControl( ){ *代码省略* }public void setCommand(int slot,Command onCommand,Command offCommand){(4)=onCommand;(5)=offCommand;}public void onButtonWasPushed(int slot){(6);}public void offlButtonWasPushed(int slot){(7);}}class RemoteLoader{public static void main(String[]args){RemoteControl remoteControl=new RemoteControl( );Light livingRoomLight=new Light( Living Room );Light kitchenLight=new Light( kitchen );LightOnCommand livingRoomLightOn=new LightOnCommand(livingRoomLight);LightOffCommand livingRoomLightOff=new LightOffCommand(livingRoomLight);LightOnCommand kitchenLightOn=new LightOnCommand(kitchenLight);LightOffCommand kitchenLightOff=new LightOffCommand(kitchenLight);remoteControl.setCommand(0,livingRoomLightOn,livingRoomLightOff);remoteControl.setCommand(1,kitchenLightOn,kitchenLightOff);remoteControl.onButtonWasPushed(0);remoteControl.offButtonWasPushed(0);remoteControl.onButtonWasPushed(1);remoteControl.offButtonWasPushed(1);}}