您好我正在尝试编译一个子类Car.java，它扩展了抽象类Vehicle.java并实现了Comparable接口。
当我尝试编译Car.java类时，我收到以下错误：
Car不是抽象的，并且不会覆盖抽象方法获取Vehicle中的PassengerCapacity（）， 找不到标志 和 缺少方法体，或声明抽象
我该怎么做才能纠正它？
Car.java类扩展了Abstact类车辆，并实现了Comparable接口
即： 公共类汽车扩展汽车实施可比较
我必须编写2个类Car.java和Bus.java。它们既可以扩展车辆又可以实现可比性。
我需要运行程序selectionSort.java和SortVehicle.java。
这些错误阻止我完成我的类Car.java，因为我无法通过它们然后能够编写Bus.java类，然后运行SortSelection.java和SortVehicle.java程序。
已向我提供了Vehicle.java，SelectionSort.java和SortVehicle.java，没有任何错误或问题。
对于纠正这些错误的任何帮助，我将不胜感激。
我的Car.java代码是：
public class Car extends Vehicle implements Comparable
{
public static final int MAX_ENGINE_CAPACITY = 2000;
public static final int MIN_ENGINE_CAPACITY = 1800;
public static final int MAX_NUMBER_OF_SEATS = 7;
public static final int MIN_NUMBER_OF_SEATS = 7;
private String vehicleColour;
private int numberOfSeats;
private int engineCapacity;
public Car (Car otherCar)
{
super();
this.vehicleColour = otherCar.vehicleColour;
this.numberOfSeats = otherCar.numberOfSeats;
this.engineCapacity = otherCar.engineCapacity;
}
/public Car()
{
super();
this.vehicleColour = new vehicleColour();
this.numberOfSeats = MIN_NUMBER_OF_SEATS;
this.engineCapacity = MIN_ENGINE_CAPACITY;
}
public Car (String aModel, int aYearOfManufacture, String aVehicleColour, int aNumberOfSeats, int aEngineCapacity)
{
super(aModel, aYearOfManufacture);
this.vehicleColour = otherCar.vehicleColour;
this.numberOfSeats = otherCar.numberOfSeats;
this.engineCapacity = otherCar.engineCapacity;
}
public String getVehicleColour()
{
return this.vehicleColour;
}
public int getNumberOfSeats()
{
return this.numberOfSeats;
}
public int getEngineCapacity()
{
return this.engineCapacity;
}
public void setVehicleColour (String newVehicleColour);
{
if (newVehicleColour == null)
{
System.out.println("Fatal Error setting vehicle colour.");
System.exit(0);
}
else
this.vehiclColour = newVehicleColour;
}
public void setNumberOfSeats (int newNumberOfSeats)
{
if (newNumberOfSeats == null)
{
System.out.println("Fatal Error setting number Of Seats.");
System.exit(0);
}
else
this.numberOfSeats = newNumberOfSeats;
}
public void setEngineCapacity (int newEngineCapacity);
{
if (newEngineCapacity == null)
{
System.out.println("Fatal Error setting number Of Seats.");
System.exit(0);
}
else
this.engineCapacity = newEngineCapacity;
}
}
Vehicle.java代码是：
public abstract class Vehicle
{
public static final int MAX_REASONABLE_YEAR_OF_MANUFACTURE = 2100;
public static final int MIN_REASONABLE_YEAR_OF_MANUFACTURE = 1000;
private String model;
private int yearOfManufacture;
public Vehicle ()
{
this.model = "(model unspecified)";
this.yearOfManufacture = MIN_REASONABLE_YEAR_OF_MANUFACTURE;
}
public Vehicle (String aModel, int aYearOfManufacture)
{
this.model = aModel;
if (yearOfManufactureReasonable(aYearOfManufacture))
this.yearOfManufacture = aYearOfManufacture;
else
{
System.out.println("Fatal Error: unreasonable year of manufacture used defining vehicle.");
System.exit(0);
}
}
public Vehicle (Vehicle otherVehicle)
{
this.model = otherVehicle.model;
this.yearOfManufacture = otherVehicle.yearOfManufacture;
}
private static boolean yearOfManufactureReasonable(int aYearOfManufacture)
{
return (aYearOfManufacture >= MIN_REASONABLE_YEAR_OF_MANUFACTURE
&& aYearOfManufacture <= MAX_REASONABLE_YEAR_OF_MANUFACTURE);
}
public String getModel ()
{
return this.model;
}
public int getYearOfManufacture ()
{
return this.yearOfManufacture;
}
public void setModel (String aModel)
{
this.model = aModel;
}
public void setYearOfManufacture (int aYearOfManufacture)
{
if (yearOfManufactureReasonable(aYearOfManufacture))
this.yearOfManufacture = aYearOfManufacture;
}
public String toString ()
{
return (this.model + ", " + this.yearOfManufacture);
}
public boolean equals (Object otherObject)
{
if (otherObject == null)
return false;
if (getClass() != otherObject.getClass())
return false;
Vehicle otherVehicle = (Vehicle)otherObject;
return (this.model.equals(otherVehicle.model)
&& this.yearOfManufacture == otherVehicle.yearOfManufacture);
}
public abstract int getPassengerCapacity ();
public boolean greaterPassengerCapacityThan (Vehicle otherVehicle)
{
return (this.getPassengerCapacity() > otherVehicle.getPassengerCapacity());
}
}
我得到的完整错误列表如下：
Car.java:5: error: Car is not abstract and does not override abstract method get
PassengerCapacity() in Vehicle
public class Car extends Vehicle implements Comparable
^
Car.java:27: error: cannot find symbol
this.vehicleColour = new vehicleColour();
^
symbol: class vehicleColour
location: class Car
Car.java:35: error: cannot find symbol
this.vehicleColour = otherCar.vehicleColour;
^
symbol: variable otherCar
location: class Car
Car.java:36: error: cannot find symbol
this.numberOfSeats = otherCar.numberOfSeats;
^
symbol: variable otherCar
location: class Car
Car.java:37: error: cannot find symbol
this.engineCapacity = otherCar.engineCapacity;
^
symbol: variable otherCar
location: class Car
Car.java:56: error: missing method body, or declare abstract
public void setVehicleColour (String newVehicleColour);
^
Car.java:58: error: cannot find symbol
if (newVehicleColour == null)
^
symbol: variable newVehicleColour
location: class Car
Car.java:64: error: cannot find symbol
this.vehiclColour = newVehicleColour;
^
symbol: variable vehiclColour
Car.java:64: error: cannot find symbol
this.vehiclColour = newVehicleColour;
^
symbol: variable newVehicleColour
location: class Car
Car.java:69: error: incomparable types: int and <null>
if (newNumberOfSeats == null)
^
Car.java:78: error: missing method body, or declare abstract
public void setEngineCapacity (int newEngineCapacity);
^
Car.java:80: error: cannot find symbol
if (newEngineCapacity == null)
^
symbol: variable newEngineCapacity
location: class Car
Car.java:86: error: cannot find symbol
this.engineCapacity = newEngineCapacity;
^
symbol: variable newEngineCapacity
location: class Car
13 errors
答案 0 :(得分：2)
您必须在getPassengerCapacity()课程中实施Car方法，或将Car课程标记为abstract。您无法扩展抽象类并在不实现主体的情况下保留方法。如果您不想实现该方法，则此类也需要标记为abstract。
答案 1 :(得分：0)
您的错误消息指出您的类Car必须实现Vehicle中定义的抽象方法PassengerCapacity（）。如果您认为自己已经完成了，那么您可能只是在方法的签名中输错了关键字？
答案 2 :(得分：0)
现有的答案很好 - 但只是要添加，如果您使用@override注释实现抽象方法，那么如果您在方法签名中出错，那么您将立即收到错误。