java - 将 JFrame.getText() 从一个类成员传递给另一个类成员？

Question

在此代码中，我使用了 3 个类，它们都扩展了 JPanel 类，这些类的实例被添加到 JForm3 类的构造函数中的 JFrame 中。

我想知道是否有办法在 printTextOnConsole() 中显示文本字段中存在的文本(在 TextPanel 类中声明的 JTextField 实例) ButtonPanel 类中的 方法。

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class JForm3 
{
    JFrame frame;
    ButtonPanel bP;
    TextPanel tP;
    LabelPanel lP;
    public JForm3()
    {
        frame = new JFrame("Java Window.");
        bP = new ButtonPanel();
        tP = new TextPanel();
        lP = new LabelPanel();

        frame.setSize(500,100);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.getContentPane().add(BorderLayout.CENTER,tP);
        frame.getContentPane().add(BorderLayout.EAST,bP);
        frame.getContentPane().add(BorderLayout.WEST,lP);

        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
    public static void main(String[] args)
    {
        new JForm3();
    }
}
class ButtonPanel extends JPanel implements ActionListener
{
    JButton quitButton;
    JButton printButton;
    public ButtonPanel()
    {
        quitButton = new JButton("Quit");
        printButton = new JButton("Print");

        quitButton.addActionListener(this);
        printButton.addActionListener(this);


        this.setLayout(new BoxLayout(this,BoxLayout.Y_AXIS));
        this.add(quitButton);
        this.add(printButton);
    }
    public void actionPerformed(ActionEvent event)
    {
        if(event.getSource() == quitButton)
            System.exit(0);
        else
            printTextOnConsole();
    }
    public void printTextOnConsole()
    {

    }
}
class LabelPanel extends JPanel
{
    JLabel label;
    public LabelPanel()
    {
        this.setLayout(new BorderLayout());
        label = new JLabel("Enter Some Text :");
        this.add(BorderLayout.CENTER,label);
        this.setVisible(true);
    }
}
class TextPanel extends JPanel
{
    JTextField textField;
    public TextPanel()
    {
        this.setLayout(new BorderLayout());
        textField = new JTextField("Enter text here");
        this.add(BorderLayout.CENTER,textField);
        this.requestFocus();
        textField.select(0,textField.getText().length());
        this.setVisible(true);
    }

}

Answer 1

使用接口(interface)来松散耦合 JPanels 之间的文本功能。

interface TextRetriever {
   String getText();
}

然后将 TextRetriever (TextPanel) 的实例传递给 ButtonPanel

class ButtonPanel extends JPanel implements ActionListener {
    private TextRetriever textRetriever;

    public ButtonPanel(TextRetriever textRetriever) {
       this.textRetriever = textRetriever
       ...
    }

    public void printTextOnConsole() {
        String text = textRetriever.getText();
    }
}