JComboBox -箭头和标签之间的填充/间距

import javax.swing.*;
import javax.swing.border.EmptyBorder;

public class ComboBoxExample {
    public static void main(String[] args) {
        JFrame frame = new JFrame("JComboBox Example");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // 创建一个JComboBox对象
        JComboBox<String> comboBox = new JComboBox<>();
        comboBox.addItem("Option 1");
        comboBox.addItem("Option 2");
        comboBox.addItem("Option 3");

        // 设置填充/间距
        comboBox.setBorder(new EmptyBorder(5, 10, 5, 10));

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