Referencing another class with multiple types.

Question

Here's my code:
import java.io.*;
import java.util.Scanner;
class CH3_13
    public static void main ( String args[] )
        Scanner input = new Scanner( System.in );
     // Invoice MyInvoice = new Invoice();
     /* myInvoice.displayInvoice();*/   }   
class Invoice
{   private String partNumber;
    private String partDescription;
    int quantity;
    double pricePerItem;
    public Invoice( String pNumber, String description, int qNumber, double price)
        partNumber = pNumber;
        partDescription = description;
        setQuantity( qNumber );
        setPricePerItem ( price );   }
      public void setPartNumber ( String pNumber )
      {   partNumber = pNumber;   }
      public String getPartNumber ()
      {   return partNumber;   }
      public void setPartDescription ( String description )
      {   partDescription = description;   }
      public String getPartDescription ()
      {   return partDescription;   }
      public void setQuantity ( int qNumber )
      {   quantity = ( qNumber < 0 ) ? 0 : qNumber;   }
      public int getQuantity ()
      {   return quantity;   }
      public void setPricePerItem ( double price )
      {   pricePerItem = ( price < 0.0) ? 0.0 : price;   }
      public double getPricePerItem ()
      {   return pricePerItem;   }
      public double getInvoiceAmount()
      {   return getQuantity() * getPricePerItem();   }
       public void displayInvoice ()
      {   System.out.println("The part number is" + getPartNumber() );
          System.out.println("The part description is" + getPartDescription() );
          System.out.println("The quantity number is" + getQuantity() );
          System.out.println("The price per item is" + getPricePerItem() );
          System.out.println("The invoice amount is" + getInvoiceAmount() );   }          
}The problem is.. I cannot use the line:
// Invoice MyInvoice = new Invoice(); (it's commented out for that reason)
... because it seems I cannot reference it because the Invoice class has multiple types defined in it. As this is the case, is there anyway, I'd be able to get that line to compile?

Answer 1

I am not sure of this is what you are looking for but I would definitely suggest some real refactoring here. First of all the part no. name description donot belong to the invoice class so they need to go into a different class named part no. Secondly you need to identify the relationship which I would say would be has a relationship between invoice and part. A many to many relationship. SInce its many to many I would guess it would need to be biderectional associaition.
However if we have a defined no. of parts in the inventory I would suggest using the reference objects, by predefining them and loading them into memory to ensure that if every time an invoice has a part, a new part object is not created.