如何在Java中正确使用printf格式化

Question

我正在尝试创建一个简单的程序来接收三个项目，它们的数量和价格，并将它们全部加在一起以创建一个简单的收据类型格式。我的教授给了我一个特定的收据格式，其中所有小数都排成一行并且一致地放置。它看起来应该是这样的。

Your Bill:


Item                           Quantity       Price         Total
Diet Soda                            10        1.25         12.50
Candy                                1         1.00          1.00
Cheese                               2         2.00          4.00


Subtotal                                                    17.50
6.25% Sales Tax                                              1.09
Total                                                       18.59

我的教授指出名称应该有30个字符，数量和价格应该是10个字符和总数。这样做我必须使用printf方法。到目前为止，我正在尝试使用此代码对其进行格式化。

import java.util.Scanner;
class AssignmentOneTest {

    public static void main(String[] args) {
        Scanner kb = new Scanner(System.in);

        // System.out.printf("$%4.2f for each %s ", price, item);
        // System.out.printf("
The total is: $%4.2f ", total);

        // process for item one
        System.out.println("Please enter in your first item");
        String item = kb.nextLine();
        System.out.println("Please enter the quantity for this item");
        int quantity = Integer.parseInt(kb.nextLine());
        System.out.println("Please enter in the price of your item");
        double price = Double.parseDouble(kb.nextLine());

        // process for item two
        System.out.println("Please enter in your second item");
        String item2 = kb.nextLine();
        System.out.println("Please enter the quantity for this item");
        int quantity2 = Integer.parseInt(kb.nextLine());
        System.out.print("Please enter in the price of your item");
        double price2 = Double.parseDouble(kb.nextLine());
        double total2 = quantity2 * price2;
        // System.out.printf("$%4.2f for each %s ", price2, item2);
        // System.out.printf("
The total is: $%4.2f ", total2);

        // process for item three
        System.out.println("Please enter in your third item");
        String item3 = kb.nextLine();
        System.out.println("Please enter the quantity for this item");
        int quantity3 = Integer.parseInt(kb.nextLine());
        System.out.println("Please enter in the price of your item");
        double price3 = Double.parseDouble(kb.nextLine());
        double total3 = quantity3 * price3;
        // System.out.printf("$%4.2f for each %s ", price3, item3);
        // System.out.printf("
The total is: $%4.2f ", total3);

        double total = quantity * price;

        double grandTotal = total + total2 + total3;
        double salesTax = grandTotal * (.0625);
        double grandTotalTaxed = grandTotal + salesTax;

        String amount = "Quantity";
        String amount1 = "Price";
        String amount2 = "Total";
        String taxSign = "%";

        System.out.printf("
Your bill: ");
        System.out.printf("

Item");
        System.out.printf("%30s", amount);
        // System.out.printf("
%s %25d %16.2f %11.2f", item, quantity, price,
        // total);
        // System.out.printf("
%s %25d %16.2f %11.2f", item2,quantity2, price2,
        // total2);
        // System.out.printf("
%s %25d %16.2f %11.2f", item3,quantity3, price3,
        // total3);

        System.out.printf("
%s", item);
        System.out.printf("%30d", quantity);
        System.out.printf("
%s", item2);
        System.out.printf("
%s", item3);

        System.out.printf("


Subtotal %47.2f", grandTotal);
        System.out.printf("
6.25 %s sales tax %39.2f", taxSign, salesTax);
        System.out.printf("
Total %50.2f", grandTotalTaxed);    
    }
}

如果我输入更长的商品名称，则会移动数量，价格和总数的位置。我的问题是，如何使用printf创建一个有限宽度的设置起点，请帮忙。