所以我整个下午都在看这段代码，我看不到错误。这是我应该做的：
为送货服务创建一个Delivery类。该类包含包含以下内容的字段：
- 包含八位数字的交货编号。前四位数字代表年份，后四位数字代表交货编号。
- 代表交货区域的代码。本地配送为代码 1，长途配送为代码 2。
- 要交付的物品的重量（以磅为单位）。
- 送货费用如下：
为该类创建一个构造函数，该构造函数Delivery接受年份、年内交付数量、交付距离代码和包裹重量的参数。施工方确定八位数的送货单号和送货费。还包括一个显示每个Delivery对象字段的方法。将文件另存为 Delivery.java。
接下来，创建一个应用程序，提示用户输入数据以进行交付。不断提示用户输入以下每个值，直到它们有效：
- 2001 年至 2025 年之间的四位数年份
- 1 到 9999（含）之间的年份的交货编号
- 包裹重量在 0.10 磅到 100 磅之间（含）
- 送货距离代码为 1 或 2
当所有数据条目都有效时，构造一个Delivery对象，然后显示其值。将文件另存为CreateDelivery.java.
所以这是我的送货班
import javax.swing.*;
import java.util.*;
class Delivery
{
//variables
private int year;
private int deliveryNumber; //deliveryNo
private double weight;
private int distanceCode; //code
//constructor
//Delivery()
//{
// year = year;
// deliveryNumber = deliveryNumber;
// weight = weight;
// distanceCode = distanceCode;
//}
//get year
public int getYear()
{
return year;
}
//set year
public int setYear (int newYear)
{
year = newYear;
return year;
}
//get deliveryNumber
public int getDeliveryNumber()
{
return deliveryNumber;
}
//set deliveryNumber
public int setDeliveryNumber (int newDeliveryNumber)
{
deliveryNumber = newDeliveryNumber;
return deliveryNumber;
}
//get weight
public double getWeight()
{
return weight;
}
//set Weight
public double setWeight (double newWeight)
{
weight = newWeight;
return weight;
}
//get distanceCode
public int getDistanceCode()
{
return distanceCode;
}
//set distanceCode
public int setDistanceCode (int newDistanceCode)
{
distanceCode = newDistanceCode;
return distanceCode;
}
//calculate fee
public double displayFees(int distance, double w) //distance = c
{
double fees = 0;
if(distance == 1)
{
if(w < 5)
{
fees = 12;
}
else if((w < 20)&&(w > 5))
{
fees = 16.50;
}
else if(w > 20)
{
fees = 22;
}
}
else if(distance == 2)
{
if(w < 5)
{
fees = 35;
}
else if(w >= 5)
{
fees = 47.95;
}
}
return fees;
}
//display method
public void display(int year, int deliveryNumber, double weight, int distanceCode)
{
System.out.println("Year: " + year + '\n'
+ "Delivery Number: " + deliveryNumber + '\n'
+ "Weight of the package: " + weight + '\n'
+ "Delivery code: " + distanceCode);
}
}
这是我的 CreateDelivery 类
import javax.swing.JOptionPane;
import java.util.Scanner;
public class CreateDelivery
{
public static void main(String []args)
{
Delivery delivery1 = new Delivery();
//scanner year
Scanner input = new Scanner(System.in);
System.out.print("Please enter the current year, format (yyyy) >>> ");
delivery1.setYear(input.nextInt());
//loop year
while((delivery1.getYear() <= 2000)||(delivery1.getYear() >= 2026))
{
System.out.println('\n'+ "Error, year should be in the range of (2010 - 2025). Please enter a valid option >> ");
delivery1.setYear(input.nextInt());
}
//scanner for delivery number
System.out.print('\n'+ "Please enter a delivery number: ");
delivery1.setDeliveryNumber(input.nextInt());
//loop for delivery number
while((delivery1.getDeliveryNumber() <= 0001)||(delivery1.getDeliveryNumber() >= 10000))
{
System.out.println("Error, the delivery number is a 4 digit number between 0001 and 9999, please enter a valid option >> ");
delivery1.setDeliveryNumber(input.nextInt());
}
//scanner for weight
System.out.print("Please enter the weight of the package (in pounds): ");
delivery1.setWeight(input.nextDouble());
//loop for weight
while((delivery1.getWeight() <= .09)||(delivery1.getWeight() >= 101))
{
System.out.println("Error, the minimum allowed weight is 0.10 pounds and the maximum is 100 pounds. Please enter a valid weight >> ");
delivery1.setWeight(input.nextDouble());
}
//scanner for delivery code
System.out.print("Please enter 1 for local or 2 for long distance deliveries >> ");
delivery1.setDistanceCode(input.nextInt());
//loop for delivery code
while((delivery1.getDistanceCode() == 1) && (delivery1.getDistanceCode() == 2))
{
System.out.println("Error, please enter a valid distance code (1 for local deliveries and 2 for long distance deliveries) >> ");
delivery1.setDistanceCode(input.nextInt());
}
//turn int to string
String n = Integer.toString(delivery1.getDeliveryNumber());
String y = Integer.toString(delivery1.getYear());
String trackingNumber = n + y;
System.out.println(delivery1.getDistanceCode() + " "
+ trackingNumber + " " + delivery1.getWeight() + " " + fees);
}
}
所以我做了你们建议的更改，但现在我无法从 Delivery 课程中收取费用。有什么想法吗？