从List 获取数据，并将其放入String对象

Question

我正在制作一个Java简单的应用程序以更好地学习代码，并结合了intellji上的一些GUI我已经有一个主页，我只是尝试制作一个弹出表，其中包含我产品上的所有数据，这是我的tableView代码：

public class ProductTable extends JFrame
{

    private Model.product product;
    private List<product> list;
    public ProductTable() {

        list=product.ProductList();

        //headers for the table

        String[] columns = {"Product Name",
                "Quantity",
                "Expiration day",
                "Need fridge"};
        Object[][] data = new Object[][] {
        };
        //create table with data
        JTable table = new JTable(data, columns);
        //add the table to the frame
        this.add(new JScrollPane(table));
        this.setTitle("ProductList");
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.pack();
        this.setVisible(true);
    }
    public static void main(String[] args)
    {
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                new ProductTable();
            }
        });
    }
}   

关于我拥有的产品类别：

product.name =字符串

product.quantity = int

Product.Expiration_day = String

product.fridge =布尔值

我想加载到字符串对象中

Data = {{product.name，product.quantity，Product.Expiration_day，Product.fridge}，{.....，....，....，...} {..... .........}};

直到我现在放出所有数据，我知道如何知道大小，但我需要将其逐个加载到数据对象中，任何人都可以通过它进行引导吗？！

我的产品代码：

package Model;

import java.sql.*;

import java.util.ArrayList;

import java.util.List;

public class product
{


    private String product_name;
    private Integer product_quantity;
    private String experation_day;
    private boolean fridge = false;
    private boolean matched= false;
    private Connection connection;

    public product()
    {
        this.product_name = "";
        this.product_quantity = 0;
        this.experation_day = "";
    }

    public product(String product_name, Integer product_quantity, String experation_day) {
        this.product_name = product_name;
        this.product_quantity = product_quantity;
        this.experation_day = experation_day;
    }

    public Integer getProduct_quantity() {
        return product_quantity;
    }

    public String getExperation_day() {
        return experation_day;
    }

    public String getProduct_name()
    {
        return product_name;
    }

    public void setProduct_quantity(Integer product_quantity) {
        this.product_quantity = product_quantity;
    }

    public void setExperation_day(String experation_day) {
        this.experation_day = experation_day;
    }

    public void setProduct_name(String product_name)
    {
        this.product_name = product_name;
    }

    public List<product> ProductList() {

        String windownsUserName = System.getProperty("user.name");
        try
        {
            System.out.println("Connecting to a selected database...");
            Connection connection = DriverManager.getConnection("jdbc:sqlite:C:\\Users\\"+windownsUserName+"\\IdeaProjects\\Software-engineer-final-project\\untitled\\src\\DButills\\account.db");
            System.out.println("Connected database successfully...");
            String sqlQuary = "SELECT product_name, product_amount, product_expration_date FROM products";
            PreparedStatement ps = connection.prepareStatement(sqlQuary);
            ResultSet rs = ps.executeQuery();
            {

            }
            List<product> products = new ArrayList<>();
            while (rs.next()) {
                product product = new product();
                product.setProduct_quantity(rs.getInt("product_amount"));
                product.setProduct_name(rs.getString("product_name"));
                product.setExperation_day(rs.getString("product_expration_date"));
                products.add(product);
            }
            return products;

        } catch (SQLException e) {
            System.out.println("Query failed: " + e.getMessage());
            return null;
        }
    }
}

Answer 1

为什么需要String？根据您提供的代码-您需要的是数组Object [] [] []，但使用值填充，因此只需遍历产品列表并填充data以正确的顺序。