If nothing better comes along, you might look at fillArc. This is
especially easy if you already know the angle of the line.

I didn't find any either.

.ed

--
www.EdmundKirwan.com - Home of The Fractal Class Composition.

package com.edmundkirwan.frac.view.gui.grid;
import java.awt.Point;
import java.awt.Graphics2D;
import java.awt.Polygon;
import java.awt.Dimension;
import com.edmundkirwan.frac.ir1.Options;
import com.edmundkirwan.frac.view.gui.ir1.Connection;
import com.edmundkirwan.frac.view.gui.ir1.RealEstateManager;

/**
* This class is a connection's arrow head pointing east. The arrow head
* itself will be a filled triangle.
*/
class FullEastArrowHead extends CommonArrowHead {

   /**
    * Constructor - stores the tip of the arrow head.
    *
    * @param tipCoords coordinates of the arrow head tip
    * @param connection connection that owns this arrow head
    */
   FullEastArrowHead(Point tipCoords, Connection connection) {
    super(tipCoords, connection);
   }

   /**
    * Draws the arrow head into the given graphical context.
    *
    * @param graphics2D graphics context
    */
   public void draw(Graphics2D graphics2D) {
    RealEstateManager realEstateManager =
       guiRegistry.getDrawFacade().getRealEstateManager();
    Dimension directoryDimension = realEstateManager.
       getDirectoryDimension(connection.getSourceNode());
    double height = directoryDimension.getHeight();

    // Establish the basic size of the arrow head
    int arrowHeadLength = (int)
       (height / Options.ARROW_HEAD_RATIO_TO_DIRECTORY_HEIGHT);
    Polygon poly = new Polygon();
    int x = (int)tipCoords.getX();
    int y = (int)tipCoords.getY();
    x = realEstateManager.getScreenXPosition(x);
    y = realEstateManager.getScreenYPosition(y);
    int startX = x;
    int startY = y;
    poly.addPoint(startX, startY);
    x = x - (arrowHeadLength / 2);
    y = y - (arrowHeadLength / 2);
    poly.addPoint(x, y);
    y = y + arrowHeadLength;
    poly.addPoint(x, y);
    poly.addPoint(startX, startY);
    draw(graphics2D, poly);
   }
}

you can define shape of appropriate form and then use Graphics2D methods
fill(Shape) and draw(Shape)
in com.imagero.gui.swing.Shapes.java I defined some basic shapes (triangles,
arrows, circles, rectangles, twin and quad arrows).
There are also an applet which uses it:
http://jgui.imagero.com/examples/JShape/

here is an arrow looking at north:

   public static Area createArrow(int width, int height, int length, int
direction) {
       int arrowStart = Math.abs(length - height);
       int lineWidth = width / 3;
               return new Area(new Polygon(
                       new int[]{lineWidth, lineWidth, 0, width / 2, width,
width - lineWidth, width - lineWidth},
                       new int[]{0, arrowStart, arrowStart, length,
arrowStart, arrowStart, 0},
                       7));
}
you can use AffineTransforn tomake it looking at any direction.