BufferStrategy in windowed mode causes constant intense white screen flicker

I put this code together based on a lot of examples I found around here on stackoverflow. When I run the program the entire screen flickers intensely. I'm sure there is something simple I'm overlooking, but so far have been unable to track down a solution. I've been debugging this for a couple hours mostly with the help of online forum reading, so I figured it was time to ask the audience.

public class Screen extends JComponent {

    @Override
    public Dimension getPreferredSize(){
        Dimension tempDimension = Toolkit.getDefaultToolkit().getScreenSize();
        return tempDimension;
    }

    @Override
    protected void paintComponent(Graphics g) {

        super.paintComponent(g);
        Graphics2D g2D = (Graphics2D)bufferStrategy.getDrawGraphics();
        g2D.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER)); //sprites overlap instead of overwrite
        if(game==null){
            drawSplash(g2D);
        }else{
            drawBoard(g2D);
        }
        g2D.dispose();
        bufferStrategy.show();
    }
}

If any additional code is required, I can provide it. Thank you for your help, stackoverflow!