试题六（共15分）
阅读下列说明和Java代码，将应填入(n)处的字句写在答题纸的对应栏内。
【说明】
某大型商场内安装了多个简易的纸巾售卖机，自动出售2元钱一包的纸巾，且每次仅售出一包纸巾。纸巾售卖机的状态图如图6-1所示。
采用状态(State)模式来实现该纸巾售卖机，得到如图6-2所示的类图。其中类State为抽象类，定义了投币、退币、出纸巾等方法接口。类SoldState、SoldOutState、NoQuarterState和HasQuarterState分别对应图6-1中纸巾售卖机的4种状态：售出纸巾、纸巾售完、没有投币、有2元钱。
【Java代码】
import j ava.util.*;
interface State{
public void insertQuarter(); //投币
public void ejectQuarter(); //退币
public void turnCrank();腑安下“出纸巾”按钮
public void dispense(); //出纸巾
}
class TissueMachine {
(1 ) soldOutState, noQuarterState, hasQuarterState, soldState, state;
state = soldOutState;
int count = 0; //纸巾数
public TissueMachine(intnumbers) { /*实现代码省略 */}
public StategetHasQuarterState() { returnhasQuarterState; }
public StategetNoQuarterState() { returnnoQuarterState, }
public State getSoldState() { return soldState; }
public State getSoldOutState() { return soldOutState; }
public int getCount() { return count, }
//其余代码省略
}
class NoQuarterState implements State {
TissueMachine tissueMachine;
public void insertQuarter() {
tissueMachine.setState((2));
}
//构造方法以及其余代码省略
}
class HasQuarterState implements State {
TissueMachine tissueMachine;
public void ejectQuarter() {
tissueMachine.setState ((3));
}
//构造方法以及其余代码省略
}
class SoldState implements State {
TissueMachine tissueMachine;
public void dispense() {
if(tissueMachine.getCount() ＞ 0) {
tissueMachine.setState ((4));
} else {
tissueMachine.setState ((5)); }
}
}