scrollPane.setViewportView(table)

这段代码的作用是将一个表格（table）添加到一个滚动面板（scrollPane）中，并使其可以滚动显示。通常情况下，当一个表格的数据比较多时，我们希望它能够在一个固定大小的区域内显示，而不是让它的大小随着数据的增加而不断扩大。这时就可以使用滚动面板来实现这个功能。通过将表格添加到滚动面板中，当表格的数据超出可视区域时，用户就可以通过滚动面板来查看剩余的数据。

相关问题

报错default table modeol cannot be resolved to be a type，下面是tablemodel的代码， JScrollPane scrollPane = new JScrollPane(); scrollPane.setBounds(10, 270, 414, 90); contentPane.add(scrollPane); expressTable = new JTable(); expressTable.setModel(new DefaultTableModel( new Object[][] {}, new String[] {"快递单号", "类别/物品", "金额", "寄件人", "收件人"} // added columns for tracking number, sender, and receiver )); tableModel = (DefaultTableModel) expressTable.getModel(); scrollPane.setViewportView(expressTable);能否封装这段代码，并在receiveexpressframe中调用

你可以将这段代码封装到一个方法中，并在`ReceiveExpressFrame`类中调用该方法。以下是封装后的代码：

public class SearchExpress {
    private DefaultTableModel tableModel;
    private JTable expressTable;

    public void setupExpressTable(JScrollPane scrollPane, JPanel contentPane) {
        scrollPane.setBounds(10, 270, 414, 90);
        contentPane.add(scrollPane);

        expressTable = new JTable();
        expressTable.setModel(new DefaultTableModel(
                new Object[][] {},
                new String[] {"快递单号", "类别/物品", "金额", "寄件人", "收件人"}
        ));
        tableModel = (DefaultTableModel) expressTable.getModel();
        scrollPane.setViewportView(expressTable);
    }

    public DefaultTableModel getTableModel() {
        return tableModel;
    }

    public JTable getExpressTable() {
        return expressTable;
    }
}

在`SearchExpress`类中，我们将原始代码封装到了`setupExpressTable`方法中。该方法接受一个`JScrollPane`和一个`JPanel`作为参数，用于设置表格的位置并添加到面板中。同时，我们添加了两个getter方法，用于获取表格的`DefaultTableModel`和`JTable`实例。

然后，在`ReceiveExpressFrame`类中，你可以创建一个`SearchExpress`对象，并调用`setupExpressTable`方法来设置表格：

public class ReceiveExpressFrame extends JFrame {
    private SearchExpress searchExpress;

    public ReceiveExpressFrame() {
        searchExpress = new SearchExpress();

        // 创建 JScrollPane 和 JPanel 实例
        JScrollPane scrollPane = new JScrollPane();
        JPanel contentPane = new JPanel();

        // 调用 setupExpressTable 方法设置表格
        searchExpress.setupExpressTable(scrollPane, contentPane);

        // 其他代码...
    }

    // 其他方法...
}

这样，你可以在`ReceiveExpressFrame`类中调用`searchExpress.getTableModel()`和`searchExpress.getExpressTable()`方法来获得表格的`DefaultTableModel`和`JTable`实例，以便后续操作。

Button sendButton = new JButton("发出"); sendButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { String customer = customerTextField.getText(); String paymentStr = paymentTextField.getText(); String getperson = receiverTextField.getText(); String sendperson = senderTextField.getText(); String trackingNumber = trackingNumberTextField.getText(); // get tracking number from new text field if (customer.isEmpty() || paymentStr.isEmpty()) { return; } double payment = Double.parseDouble(paymentStr); totalIncome += payment; tableModel.addRow(new Object[]{trackingNumber, customer,payment,sendperson,getperson}); // add tracking number to table customerTextField.setText(""); paymentTextField.setText(""); trackingNumberTextField.setText(""); receiverTextField.setText(""); senderTextField.setText("");; trackingNumberTextField.setText(""); // clear tracking number text field try { BufferedWriter writer = new BufferedWriter(new FileWriter("sendexpress.txt", true)); writer.write(trackingNumber + ", "+ customer + ", " + payment + ", " + sendperson + ", " + getperson); writer.newLine(); writer.close(); } catch (IOException ex) { ex.printStackTrace(); } } });和xpressTable = new JTable(); expressTable.setModel(new DefaultTableModel( new Object[][] {}, new String[] {"快递单号", "类别/物品", "金额", "寄件人", "收件人"} // added columns for tracking number, sender, and receiver )); tableModel = (DefaultTableModel) expressTable.getModel(); scrollPane.setViewportView(expressTable);单独封装成两个类

您的代码可以封装成两个类，一个是用于创建界面和处理按钮点击事件的类，另一个是用于管理数据和文件操作的类。

第一个类可以命名为`ExpressForm`，其中包含以下内容：

import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

public class ExpressForm {
    private JTextField customerTextField;
    private JTextField paymentTextField;
    private JTextField senderTextField;
    private JTextField receiverTextField;
    private JTextField trackingNumberTextField;
    private JButton sendButton;
    private JTable expressTable;
    private JScrollPane scrollPane;

    private DefaultTableModel tableModel;
    private double totalIncome;

    public ExpressForm() {
        sendButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                String customer = customerTextField.getText();
                String paymentStr = paymentTextField.getText();
                String getperson = receiverTextField.getText();
                String sendperson = senderTextField.getText();
                String trackingNumber = trackingNumberTextField.getText();

                if (customer.isEmpty() || paymentStr.isEmpty()) {
                    return;
                }
                double payment = Double.parseDouble(paymentStr);
                totalIncome += payment;
                tableModel.addRow(new Object[]{trackingNumber, customer, payment, sendperson, getperson});
                customerTextField.setText("");
                paymentTextField.setText("");
                trackingNumberTextField.setText("");
                receiverTextField.setText("");
                senderTextField.setText("");
                trackingNumberTextField.setText("");

                try {
                    BufferedWriter writer = new BufferedWriter(new FileWriter("sendexpress.txt", true));
                    writer.write(trackingNumber + ",   " + customer + ",   " + payment + ",   " + sendperson + ",   " + getperson);
                    writer.newLine();
                    writer.close();
                } catch (IOException ex) {
                    ex.printStackTrace();
                }
            }
        });
    }

    public static void main(String[] args) {
        JFrame frame = new JFrame("Express Form");
        frame.setContentPane(new ExpressForm().scrollPane);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
    }
}

第二个类可以命名为`ExpressManager`，用于管理数据和文件操作：

import javax.swing.table.DefaultTableModel;

public class ExpressManager {
    private DefaultTableModel tableModel;
    private double totalIncome;

    public ExpressManager(DefaultTableModel tableModel) {
        this.tableModel = tableModel;
        this.totalIncome = 0.0;
    }

    // 添加数据到表格和文件
    public void addData(String trackingNumber, String customer, double payment, String sendperson, String getperson) {
        totalIncome += payment;
        tableModel.addRow(new Object[]{trackingNumber, customer, payment, sendperson, getperson});

        try {
            BufferedWriter writer = new BufferedWriter(new FileWriter("sendexpress.txt", true));
            writer.write(trackingNumber + ",   " + customer + ",   " + payment + ",   " + sendperson + ",   " + getperson);
            writer.newLine();
            writer.close();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

    // 获取总收入
    public double getTotalIncome() {
        return totalIncome;
    }
}

您可以将第一个类的`main`方法作为入口点运行，这样就可以创建一个包含界面和按钮点击事件处理的窗口。第二个类用于数据管理和文件操作，可以在第一个类的按钮点击事件中调用相应的方法来添加数据到表格和文件。

请注意，这只是一个简单的示例，您可能需要根据实际需求进行适当的修改和调整。