When trying to draw a string with alpha composite mode "clear", nothing is drawn (or rather removed), when RenderingHints.KEY_TEXT_ANTIALIASING, is set to RenderingHints.VALUE_TEXT_ANTIALIAS_ON.

Demo code
=========

import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;

public class CompositeDemo {

    public static void main(final String[] args) {
        final ImageIcon imageIconWithAntiAliasing = createIcon(true);
        final ImageIcon imageIconWithoutAntiAliasing = createIcon(false);
        final JFrame frame = new JFrame();
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(new FlowLayout());
        frame.getContentPane().add(new JLabel(imageIconWithAntiAliasing));
        frame.getContentPane().add(new JLabel(imageIconWithoutAntiAliasing));
        SwingUtilities.invokeLater(() -> {
            frame.setSize(250, 100);
            frame.setVisible(true);
        });
    }

    private static ImageIcon createIcon(final boolean textAntiAlias) {
        final BufferedImage image = new BufferedImage(100, 50, BufferedImage.TYPE_INT_ARGB);
        final Graphics2D g = (Graphics2D)image.getGraphics();
        if (textAntiAlias) {
            g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
        }

        g.setColor(Color.BLACK);
        g.drawRect(0, 0, 99, 49);
        g.setColor(Color.RED);
        g.fillRect(0, 0, 50, 50);
        g.setComposite(AlphaComposite.Clear);
        g.setColor(Color.BLUE);
        g.drawString("sdfegergerwgrtwgtrw", 0, 25);

        return new ImageIcon(image);
    }
}

A screenshot is attached. The text should be visible in both labels, but is only visible in the one without text anti-aliasing.

Workaround:
Change the AlphaComposite rule to AlphaComposite.DstOut.