多個班級：我在這裏做錯了什麼？

Question

我已經正式走到了我的繩索的盡頭。我找不到我做錯了什麼。我已經完成了這個程序幾乎完全像我前幾天寫的另一個程序，但我編譯時遇到問題。我不知道爲什麼我在輸出線上出現錯誤。請幫助：

這是RUNNING FILE：

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()); 

    } 
    } 
} 

這是數據集合文件：

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

它爲什麼不編譯的原因是因爲您的主要代碼：

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()但你的getName（）實現不存在。你沒有正確的簽名。將它改爲適當的吸氣劑，它應該可以工作。其他獲得者也一樣。

相反的：

// 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; 
    } 

Answer 2

我相信這個問題是您正在閱讀的值的方式。雖然使用Scanner.next()可以安全地讀取Strings，但對於其他數據結構，在實際讀取值之前，可能需要從輸入流中清除新的行字符。

但是這只是在理論上，因爲你幾乎沒有給你的問題。