for(__(5)__ : order){
if
numbe r += item.getQuantity();
}
}
stdOut.println(product.getCode() + ” ”
+ product.getDescription() + ” ”
+ number + ” ” + number *product.getPrice());
}
}
//其余的方法未列出
}
2、[说明]
传输门是传输系统中的重要装置。传输门具有 Open(打开)、Closed(关闭)、Opening(正在打开)、StayOpen(保持打开)、Closing(正在关闭)五种状态。触发状态的转换事件有 click、complete 和 timeout 三种。事件与其相应的状态转换如图 2-1 所示。
图 2-1 传输门响应事件与其状态转换图
下面的[Java 代码 1]与[Java 代码 2]分别用两种不同的设计思路对传输门进行状态模拟，请填补代码中的空缺。
[Java 代码 1]
public class Door {
public static final int CLOSED = 1;
public static final int OPENING = 2;
public static final int OPEN = 3;
public static final int CLOSING = 4;
public static final int STAYOPEN = 5;
private int state = CLOSED;//定义状态变量，用不同的整数表示不同状态
private void setState(int state){this.state = state;} //设置传输门当前状态
public void getState(){
// 此处代码省略，本方法输出状态字符串，
// 例如，当前状态为 CLOSED 时,输出字符串为”CLOSED”
}
public void click() { //发生 click 事件时进行状态转换
if ((1) ) setState(OPENING);
else if ( (2) ) setState(CLOSING);
else if ((3) ) setState(STAYOPEN);
//发生 timeout 事件时进行状态转换
public void timeout(){ if (state == OPEN) setState(CLOSING); }
public void complete(){ //发生 complete 事件时进行状态转换
if (state == OPENING) setState(OPEN);
else if (state == CLOSING) setState(CLOSED);
}
public static void main(String [] args){
Door aDoor = new Door();
aDoor.getState();
aDoor.click();
aDoor.getState();
aDoor.complete();
aDoor.getState();
aDoor.click();
aDoor.getState();
aDoor.click();
aDoor.getState();
return;
}
}
[Java 代码 2]
public class Door {
public final DoorState CLOSED = new DoorClosed(this);
public final DoorState OPENING = new DoorOpening(this);
public final DoorState OPEN = new DoorOpen(this);
public final DoorState CLOSING = new DoorClosing(this);
public final DoorState STAYOPEN = new DoorStayOpen(this);
private DoorState state = CLOSED;
//设置传输门当前状态
public void setState(DoorState state){ this.state = state;}
public void getState(){ //根据当前状态输出对应的状态字符串
System.out.println(state.getClass().getName());
}
public void click(){ (4) ;} //发生 click 事件时进行状态转换
public void timeout(){ (5) ;}//发生 timeout 事件时进行状态转换
public void complete(){ (6) ;}//发生 complete 事件时进行状态转换