Bordas Coloridas

/*
* JDK 20
*
* @Author:Oner
*
*/

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

public class BordasExp2 extends JFrame {

    public BordasExp2() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setPreferredSize(new Dimension(300, 100));
        setLayout(new GridLayout(1, 2));

        JButton botaoLinhaChanfro = createButton("Linha Chanfro", LineBorder.createBlackLineBorder());
        JButton botaoArcoIris = createButton("Arco-Iris", createRainbowBorder());

        setLocationRelativeTo(null);
        add(botaoArcoIris);
        add(botaoLinhaChanfro);
        pack();
    }

    private JButton createButton(String text, Border border) {
        JButton button = new JButton(text);
        button.setBorder(border);
        return button;
    }

    private Border createRainbowBorder() {
        Border[] colorBorders = {
                BorderFactory.createLineBorder(Color.orange),
                BorderFactory.createLineBorder(Color.yellow),
                BorderFactory.createLineBorder(Color.green),
                BorderFactory.createLineBorder(Color.blue),
                BorderFactory.createLineBorder(Color.magenta)
        };

        CompoundBorder compoundBorder = new CompoundBorder(Color.red != null ? BorderFactory.createLineBorder(Color.red) : null, colorBorders[0]);

        for (int i = 1; i < colorBorders.length; i++) {
            compoundBorder = new CompoundBorder(colorBorders[i], compoundBorder);
        }

        return compoundBorder;
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(() -> {
            BordasExp2 bordasExp2 = new BordasExp2();
            bordasExp2.setVisible(true);
        });
    }
}