java - 多个类: What am I doing wrong here?

Question

我已经正式走到了穷途末路的地步。我找不到我做错了什么。我完成的这个程序几乎与我几天前编写的另一个程序一模一样，但我在编译时遇到了问题。我不知道为什么输出线上出现错误。请帮忙:

这是正在运行的文件:

package inventory1;

import java.util.Scanner;

public class RunApp {
  public static void main(String[] args) {

    Scanner input = new Scanner(System.in);

    DataCollection theProduct = new DataCollection();

    String Name = "";
    double pNumber = 0.0;
    double Units = 0.0;
    double Price = 0.0;

    while (true) {
      System.out.print("Enter Product Name: ");
      Name = input.next();
      theProduct.setName(Name);
      if (Name.equalsIgnoreCase("stop")) {
        return;}    
      System.out.print("Enter Product Number: ");
      pNumber = input.nextDouble();
      theProduct.setpNumber(pNumber);

      System.out.print("Enter How Many Units in Stock: ");
      Units = input.nextDouble();
      theProduct.setUnits(Units);

      System.out.print("Enter Price Per Unit: ");
      Price = input.nextDouble();
      theProduct.setPrice(Price);

      System.out.print("\n Product Name:     " + theProduct.getName());
      System.out.print("\n Product Number:     " + theProduct.getpNumber());
      System.out.print("\n Amount of Units in Stock:     " + theProduct.getUnits());
      System.out.print("\n Price per Unit:    " + theProduct.getPrice()  + "\n\n");
      System.out.printf("\n Total cost for %s in stock: $%.2f\n\n\n", theProduct.getName(), theProduct.calculatePrice());

    }
  }
}

这是数据收集文件:

package inventory1;

public class DataCollection {
  String productName;
  double productNumber, unitsInStock, unitPrice, totalPrice;

  public DataCollection() {
    productName = "";
    productNumber = 0.0;
    unitsInStock = 0.0;
    unitPrice = 0.0;
  }

  // setter methods
  public void setName(String name) {
    productName = name;
  }

  public void setpNumber(double pNumber) {
    productNumber = pNumber;
  }

  public void setUnits(double units) {
    unitsInStock = units;
  }

  public void setPrice(double price) {
    unitPrice = price;
  }

  // getter methods
  public void getName(String name) {
    productName = name;
  }

  public void getpNumber(double pNumber) {
    productNumber = pNumber;
  }

  public void getUnits(double units) {
    unitsInStock = units;
  }

  public void getPrice(double price) {
    unitPrice = price;
  }

  public double calculatePrice() {
    return (unitsInStock * unitPrice);
  }
}

Answer 1

无法编译的原因是你的主要代码:

  System.out.print("\n Product Name:     " + theProduct.getName());
  System.out.print("\n Product Number:     " + theProduct.getpNumber());
  System.out.print("\n Amount of Units in Stock:     " + theProduct.getUnits());
  System.out.print("\n Price per Unit:    " + theProduct.getPrice()  + "\n\n");
  System.out.printf("\n Total cost for %s in stock: $%.2f\n\n\n", theProduct.getName(), theProduct.calculatePrice());

需要 getName() 但您的 getName() 实现不存在。您没有正确的签名。将其更改为适当的 setter/getter ，它应该可以工作。其他 setter/getter 也是如此。

而不是:

  // getter methods
  public void getName(String name) {
    productName = name;
  }

  public void getpNumber(double pNumber) {
    productNumber = pNumber;
  }

  public void getUnits(double units) {
    unitsInStock = units;
  }

  public void getPrice(double price) {
    unitPrice = price;
  }

用途:

  // getter methods
  public String getName() {
    return productName;
  }

  public double getpNumber() {
    return productNumber;
  }

  public double getUnits() {
    return unitsInStock;
  }

  public double getPrice() {
    return unitPrice;
  }