如何通过set方法创建并将不同类型的新对象存储到特定的Array列表中？

Question

我正在为小工具商店创建一个GUI，用于存储小工具（例如手机和MP3播放器）的详细信息，但我不知道如何将这些详细信息的值作为类型的新对象存储到其中。小工具类型的ArrayList。

我做了很多次试验和错误，但是不能确定我是否真正在进步。

import java.util.ArrayList;
import java.awt.event.*;
import javax.swing.*;
public class GadgetShop implements ActionListener
{
    // instance variables - replace the example below with your own
    private JTextField modelTextField;
    private JTextField priceTextField;
    private JTextField weightTextField;
    private JTextField sizeTextField;
    private JTextField initialCreditTextField;
    private JButton addMobileButton;
    private JFrame frame;
    private ArrayList<Gadget> gadgets;

    /**
     * The GUI is created in the constructor.
     */
    public GadgetShop()
    {
        // initialise instance variables

        ArrayList<Gadget> gadgets = new ArrayList<Gadget>();

        frame = new JFrame("The Gadget Shop");
        Container contentPane = frame.getContentPane();
        contentPane.setLayout(new FlowLayout());

        modelTextField = new JTextField(15);
        contentPane.add(modelTextField);

        priceTextField = new JTextField(15);
        contentPane.add(priceTextField);

        weightTextField = new JTextField(15);
        contentPane.add(weightTextField);

        sizeTextField = new JTextField(15);
        contentPane.add(sizeTextField);

        initialCreditTextField = new JTextField(15);
        contentPane.add(initialCreditTextField);

        addMobileButton = new JButton("Add Mobile");
        contentPane.add(addMobileButton);
        addMobileButton.addActionListener(this);

        frame.pack();
        frame.setVisible(true);
    }

    /**
     * The main method allows the program to be run without BlueJ.
     */ 
    public static void main(String[] args)
    {
        GadgetShop calculator = new GadgetShop();
    }

    /**
     * Find which button triggered the event and call the appropriate method.
     */
    public void actionPerformed(ActionEvent event)
    {
        String command = event.getActionCommand();
        if (command.equals("Add Mobile")) {
            addMobile();
        }
    }

下面是对象详细信息的getMethods

    public String getModel()
    {
        String model
           = modelTextField.getText();
        return model;
    }

    public String getSize()
    {
        String size
           = sizeTextField.getText();
        return size;
    }

    public int getWeight()
    {
        int weight
           = Integer.parseInt(weightTextField.getText());
        return weight;
    }

    public double getPrice()
    {
        double price
           = Double.parseDouble(priceTextField.getText());
        return price;
    }

    public int getCredit()
    {
        int credit
           = Integer.parseInt(initialCreditTextField.getText());
        return credit;
    }

下面是我的setMethod，用于将Mobile类型的对象存储到我认为是错误的Gadget ArrayList中

    public void addMobile()
    {
        String mobile =
           getModel();    //Is this how I call the get Methods??
           getPrice();
           getWeight();
           getSize();
           getCredit();
        gadgets = new Mobile();
        gadgets.add(mobile);   //I get an error with the .add part
    }

}

我期望出现错误，因为我不确定我是否首先正确地创建了ArrayList。