方法输出的值不正确？
问题描述：
因此，我正在完成一项试图输出房屋内电器能耗的作业。我创建了名为ElectricCooker的Appliance和名为ElectricShower的Appliance。除了不同的变量名称之外，它们都具有完全相同的代码，但一些如何产生不同的输出。方法输出的值不正确？
下面是相关的代码：（抱歉的代码量，这个再现程序）
ElectricCooker
public class ElectricCooker extends Appliance
{
public int isOn = -1;
public int isOff = 0;
public int incrementTime;
public int varPass = -1;
@Override
public int currentState()
{
if (varPass == 0)
return isOff;
else
{
return isOn;
}
//returns isOn;
}
@Override
public void useTime(int defaultTime)
{
defaultTime = 15;
incrementTime = 4;
}
public void cook()
{
//add code
}
@Override
public void timePasses()
{
if(varPass == isOff)
varPass = 0;
else
{
ElectricMeter.getInstance().incrementConsumed(electricityUse);
ElectricMeter.getInstance().incrementConsumed(5);
int getCookerConsumed = ElectricMeter.getInstance().getElectricityUsed();
System.out.println("Electric cooker electricity consumption = " + getCookerConsumed);
}
}
ElectricCooker(int electricityUse, int gasUse, int waterUse, int timeOn)
{
super(electricityUse, gasUse, waterUse, timeOn);
this.electricityUse = 5 * incrementTime;
this.gasUse = 0 * incrementTime;
this.waterUse = 0 * incrementTime;
this.timeOn = 15 * incrementTime;
}
}
ElectricShower
public class ElectricShower extends Appliance
{
public int isOn = -1;
public int isOff = 0;
public int incrementTime;
public int varPass = -1;
@Override
public int currentState()
{
if (varPass == 0)
return isOff;
else
{
return isOn;
}
//returns isOn;
}
@Override
public void useTime(int defaultTime)
{
defaultTime = 15;
incrementTime = 4;
}
@Override
public void timePasses()
{
if(varPass == isOff)
varPass = 0;
else
{
ElectricMeter.getInstance().incrementConsumed(electricityUse);
ElectricMeter.getInstance().incrementConsumed(5);
int getShowerConsumed = ElectricMeter.getInstance().getElectricityUsed();
System.out.println("Electric shower electricity consumption = " + getShowerConsumed);
}
}
ElectricShower(int electricityUse, int gasUse, int waterUse, int timeOn)
{
super(electricityUse, gasUse, waterUse, timeOn);
this.electricityUse = 5 * incrementTime;
this.gasUse = 0 * incrementTime;
this.waterUse = 0 * incrementTime;
this.timeOn = 15 * incrementTime;
}
}
电器
abstract public class Appliance
{
public int varPass;
public int isOn;
public int isOff;
public int electricityUse, gasUse, waterUse, timeOn;
public abstract void useTime(int defaultTime);
public int currentState()
{
if (varPass == 0)
return isOff;
else
{
return isOn;
}
//returns isOn;
}
public abstract void timePasses();
Appliance(int electricityUse,int gasUse,int waterUse,int timeOn)
{
electricityUse = 0;
gasUse = 0;
waterUse = 0;
timeOn = 0;
}
}
ElectricMeter
public class ElectricMeter
{
ElectricMeter() {}
private static ElectricMeter instance = new ElectricMeter();
public static ElectricMeter getInstance() { return instance; }
private int electricityUsed = 0;
public void incrementConsumed(int value)
{
electricityUsed += value;
}
public int getElectricityUsed()
{
return electricityUsed;
}
}
家
import java.util.ArrayList;
public class House
{
ArrayList<Appliance> applianceList = new ArrayList<>();
ElectricShower calleShower = new ElectricShower(1, 1, 1, 1);
ElectricCooker calleCooker = new ElectricCooker(1, 1, 1, 1);
public void addAppliance()
{
applianceList.add(calleShower);
applianceList.add(calleCooker);
}
public void timePasses()
{
calleShower.timePasses();
calleCooker.timePasses();
//this method is called as part of the simulation to trigger a new fifteen minute period
//in the house. When it is called, it will in turn call timePasses() on all the Appliances in the House.
}
}
public class CourseworkTest {
public static void main(String[] args)
{
House callHouse = new House();
callHouse.timePasses();
}
}
输出
Electric shower electricity consumption = 5
Electric cooker electricity consumption = 10
我一直在这个小时工作，我只是不明白如何完全相同的代码可以产生不同的结果？我看不出10和其他5当他们做完全相同的事情，并通过相同的过程。非常感谢任何帮助，谢谢。
答
ElectricMeter类是一个单例，意味着在应用程序的执行过程中会存在一个（相同的）实例。
首先，从ElectricShower.timePasses()，你做以下电话：
ElectricMeter.getInstance().incrementConsumed(5);
然后，你再从ElectricCooker.timePasses()拨打这个电话。因此，当您第二次输出消耗量时，报告为10。
使用一个单身代表一个房子共同的共享电表看起来像一个合理的设计决定。
+0
啊，我看到了，感谢您的反馈意见，现在有道理。 – Tom
您拥有的另一个问题是妨碍您理解您的代码，因为您到处都有重复。删除设备的子类，并将不同的参数传递给其构造函数以创建新的设备实例。同时删除Meter类。这是没有必要的，也使你的代码复杂化。最后，这是展示问题所需的最少代码。编辑出所有不相关的东西（例如，所有不相关的字段和方法）。学习使用调试器也会有所帮助。 – Bohemian