决定批发商或零售商的价格

Question

这是我上大学的第一年，我用我自己的基本知识设计了一个代码。我设计了一个程序来计算批发商或零售商的商品价格。特殊客户如果点击按钮，也会得到特别的折扣。请看一看我的代码，并给我任何反馈，我如何实现它。如果你认为我做得很好，请告诉我。

import java.awt.Dimension;
import java.text.NumberFormat;
import java.util.ArrayList;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTextArea;

public class packingcompany extends JPanel {

    JTable jt;

    public packingcompany() {
        String[] columns = {"Wholesalers No.Units", "Wholesalers(£)", "Retailers No.Units", "Retailers (£)"};

        String[][] data = {{"1-6", "£50", "1-4", "£60"},
        {"7-11", "£40", "5-9", "£50"},
        {"12-21", "£30", "10-15", "£40"},
        {"22-60", "£20", "16-50", "£30"},
        {"60+", "£15", "50+", "£25"}};

        jt = new JTable(data, columns) {
            public boolean isCellEditable(int data, int columns) {
                return false;
            }
        };

        jt.setPreferredScrollableViewportSize(new Dimension(550, 80));
        jt.setFillsViewportHeight(true);

        JScrollPane jps = new JScrollPane(jt);
        add(jps);
    }

    public static void main(String[] args) {
        JFrame jf = new JFrame();
        packingcompany t = new packingcompany();
        jf.setTitle("The Packing Company");
        jf.setSize(600, 150);
        jf.setVisible(true);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.add(t);

        String input, sinput, result;
        int option, spec;
        int wsquantity = 0, rtquantity = 0;
        double wstotal = 0, rttotal = 0, special;

        JTextArea display = new JTextArea();       //stating that i want a JText area   
        NumberFormat money = NumberFormat.getCurrencyInstance();
        do {
            ArrayList<String> buttonChoice = new ArrayList<String>();
            buttonChoice.add("Wholesalers");
            buttonChoice.add("Retailers");
            buttonChoice.add("Exit");

            Object[] options = buttonChoice.toArray(); // i am turning the arraylist to objects 

            option = JOptionPane.showOptionDialog(null, "Select Type of Service", "The Packing Company",
                    JOptionPane.PLAIN_MESSAGE, JOptionPane.QUESTION_MESSAGE,
                    null, options, buttonChoice.get(0));

            switch (option) {

                case 0:

                    do {
                        sinput = JOptionPane.showInputDialog("Enter The Quantity You Require:");
                        try {
                            wsquantity = Integer.parseInt(sinput);
                        } catch (Exception nfe) {
                            JOptionPane.showMessageDialog(null, "We are not sure what you entered or did.");
                        }

                        if (wsquantity <= 6) {
                            wstotal = wsquantity * 50;
                        } else if (wsquantity <= 11) {
                            wstotal = wsquantity * 40;
                        } else if (wsquantity <= 21) {
                            wstotal = wsquantity * 30;
                        } else if (wsquantity <= 60) {
                            wstotal = wsquantity * 20;
                        } else if (wsquantity <= 500) {
                            wstotal = wsquantity * 15;
                        }

                        if (wsquantity > 500) {
                            JOptionPane.showMessageDialog(null, "We apologies but you can not order more than 500 units with us at once.");

                        }

                    } while (wsquantity > 500);

                    ArrayList<String> Special = new ArrayList<String>();
                    Special.add("Special Customer");
                    Special.add("Standard Customer");

                    Object[] specials = Special.toArray(); // i am turning the arraylist to objects 

                    spec = JOptionPane.showOptionDialog(null, "Which are you?", "The Packing Company",
                            JOptionPane.PLAIN_MESSAGE, JOptionPane.QUESTION_MESSAGE,
                            null, specials, Special.get(0));

                    if (spec == 0) {
                        special = wstotal - (wstotal / 100 * 10);
                        result = "                      The Packing Company for Wholesalers"
                                + "\n------------------------------------------------------------------------"
                                + "------------------"
                                + "\n\nYou Ordered " + wsquantity
                                + " Units" + "\nOriginal Price: " + money.format(wstotal) + "\n\nTotal for our Special Customers : " + money.format(special);
                        JOptionPane.showMessageDialog(null, result);
                        break;
                    } else if (spec == 1) {

                        result = "                      The Packing Company for Wholesalers"
                                + "\n------------------------------------------------------------------------"
                                + "------------------"
                                + "\n\nYou Ordered " + wsquantity
                                + " Units" + "\nTotal: " + money.format(wstotal)
                                + "\n\n\n\nWant to find out how you can become a Special Customer?" + "\nCall Us Now! 0800 3453456";
                        JOptionPane.showMessageDialog(null, result);
                        break;
                    }
                case 1:
                    do {
                        sinput = JOptionPane.showInputDialog("Enter The Quantity You Require:");
                        try {
                            rtquantity = Integer.parseInt(sinput);
                        } catch (Exception nfe) {
                            JOptionPane.showMessageDialog(null, "We are not sure what you entered.");
                        }
                        if (rtquantity <= 4) {
                            rttotal = rtquantity * 60;
                        } else if (rtquantity <= 9) {
                            rttotal = rtquantity * 50;
                        } else if (rtquantity <= 15) {
                            rttotal = rtquantity * 40;
                        } else if (rtquantity <= 50) {
                            rttotal = rtquantity * 30;
                        } else if (rtquantity <= 500) {
                            rttotal = rtquantity * 25;
                        }

                        if (rtquantity > 500) {
                            JOptionPane.showMessageDialog(null, "We apologies but you can not order more than 500 units with us at once.");

                        }
                        special = rttotal - (rttotal / 100 * 10);

                    } while (rtquantity > 500);

                    ArrayList<String> Special2 = new ArrayList<String>();
                    Special2.add("Special Customer");
                    Special2.add("Standard Customer");

                    Object[] specials2 = Special2.toArray(); // i am turning the arraylist to objects 

                    spec = JOptionPane.showOptionDialog(null, "Which are you?", "The Packing Company",
                            JOptionPane.PLAIN_MESSAGE, JOptionPane.QUESTION_MESSAGE,
                            null, specials2, Special2.get(0));

                    if (spec == 0) {
                        special = rttotal - (rttotal / 100 * 10);
                        result = "                      The Packing Company for Wholesalers"
                                + "\n------------------------------------------------------------------------"
                                + "------------------"
                                + "\n\nYou Ordered " + rtquantity
                                + " Units" + "\nOriginal Price: " + money.format(rttotal) + "\n\nTotal for our Special Customers : " + money.format(special);
                        JOptionPane.showMessageDialog(null, result);
                        break;

                    } else if (spec == 1) {
                        result = "                       The Packing Company for Retailers"
                                + "\n------------------------------------------------------------------------"
                                + "------------------"
                                + "\n\nYou Ordered " + rtquantity
                                + " Units" + "\nTotal: " + money.format(rttotal)
                                + "\n\n\n\nWant to find out how you can become a Special Customer?" + "\nCall Us Now! 0800 3453456";
                        JOptionPane.showMessageDialog(null, result);
                        break;
                    }
                case 2:
                    JOptionPane.showMessageDialog(null, "Thank you for your services." + "\nThe Packing Company");
                    System.exit(0);
            }
        } while (option != 2);
    }
}

Answer 1

几点意见：

• 类名的约定是camel大小写，第一个单词大写；例如PackingCompany而不是packingcompany -有关java命名约定的详细信息，请参阅这里。
• 无论如何，你的打包公司课程对我来说做得太多了；对于面向对象的设计，你应该试着遵循单一责任原则。
• 与其依赖于spec和option的神奇数字，不如使用枚举