RoundedBorder.java

import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.geom.Line2D;
import javax.swing.border.AbstractBorder;

public class RoundedBorder extends AbstractBorder {

public RoundedBorder(Color c, int g) {
    color = c;
    gap = g;
}

@Override
public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
    super.paintBorder(c, g, x, y, width, height);
    Graphics2D g2d;
    if (g instanceof Graphics2D) {
        g2d = (Graphics2D) g;
        g2d.setColor(color);
        System.out.println(x + y);
        g2d.draw(new Line2D.Double((double)x, (double)y + 10, (double)x + 3, (double)y + 3));
        g2d.draw(new Line2D.Double((double)x + 3, (double)y + 3, (double)x + 10, (double)y));
        g2d.draw(new Line2D.Double((double)x + 10, (double)y, (double)x + 30, (double)y));
        g2d.draw(new Line2D.Double((double)x + 30, (double)y, (double)x + 33, (double)y + 2));
        g2d.draw(new Line2D.Double((double)x + 33, (double)y + 2, (double)x + 36, (double)y + 8));
        g2d.draw(new Line2D.Double((double)x + 36, (double)y + 8, (double)x + 36, (double)y + 28));
        g2d.draw(new Line2D.Double((double)x + 36, (double)y + 28, (double)x + 34, (double)y + 31));
        g2d.draw(new Line2D.Double((double)x + 34, (double)y + 31, (double)x + 32, (double)y + 33));
        g2d.draw(new Line2D.Double((double)x + 32, (double)y + 33, (double)x + 6, (double)y + 33));
        g2d.draw(new Line2D.Double((double)x + 6, (double)y + 33, (double)x + 3, (double)y + 31));
        g2d.draw(new Line2D.Double((double)x + 3, (double)y + 31, (double)x, (double)y + 27));
        g2d.draw(new Line2D.Double((double)x, (double)y + 27, (double)x, (double)y + 10));
    }
}

@Override
public Insets getBorderInsets(Component c) {
    return (getBorderInsets(c, new Insets(gap, gap, gap, gap)));
}

@Override
public Insets getBorderInsets(Component c, Insets insets) {
    insets.left = insets.top = insets.right = insets.bottom = gap;
    return insets;
}

@Override
public boolean isBorderOpaque() {
    return true;
}

// Variable declarations
private final Color color;
private final int gap;
}