所以我正在做一项任务，试图输出房屋内电器的能耗。我创建了一个Appliance叫ElectricCooker和一个Appliance叫ElectricShower 。除了不同的变量名称之外，它们都具有完全相同的代码，但如何产生不同的输出。
以下是相关代码:(抱歉代码量较多，这重现了程序)
电饭锅
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;
}
}
电淋浴器
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;
}
}
设备
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;
}
}
电表
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;
}
}
房子
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
我已经为此工作了几个小时，但我只是不明白完全相同的代码如何以某种方式产生不同的结果？我不明白怎么会是10及其他5当他们做完全相同的事情并经历相同的过程时。非常感谢任何帮助，谢谢。
最佳答案
ElectricMeter 类是一个单例，这意味着在应用程序的整个执行过程中将存在一个(相同的)实例。
首先，从 ElectricShower.timePasses() 中进行以下调用:
ElectricMeter.getInstance().incrementConsumed(5);
然后，您再次从 ElectricCooker.timePasses() 进行此调用。因此，当您第二次输出消耗时，它将报告为 10。
使用单例来表示房屋的公共(public)共享电表似乎是一个合理的设计决策。
关于java - 方法输出的值不正确？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40923964/