Re: Detecting overridden methods..

From:

Andrew Thompson <andrewthommo@gmail.com>

Newsgroups:

comp.lang.java.programmer

Date:

Mon, 1 Jun 2009 23:25:21 -0700 (PDT)

Message-ID:

<990ae208-9343-45d9-9bf5-e56aff29df5b@n21g2000vba.googlegroups.com>

On Jun 2, 3:50 pm, Mark Space <marksp...@sbc.global.net> wrote:

Andrew Thompson wrote:

Are there better ways to detect if an arbitrary Swing applet
overrides paint(Graphics)?

(Or any method, of any class, for that matter.)

Wouldn't you be able to get this with reflection and
getDeclaredMethod()?

I mistakenly thought that would not work, since
both the applet and it's subclass should have access
to the Method. But my initial assumption was wrong,
as this code supports. Comment out the overridden
method to see an NSME stacktrace.

<sscce>
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JApplet;
import javax.swing.JOptionPane;
import java.lang.reflect.*;

public class TestAppletOverride extends JApplet {

  public void start() {
    try {
      Method testAppletPaint =
        this.
        getClass().
        getDeclaredMethod("paint", Graphics.class);

      JOptionPane.showMessageDialog(
        this,
        testAppletPaint.getDeclaringClass());
    } catch(NoSuchMethodException nsme) {
      nsme.printStackTrace();
    }
  }

  @Override
  public void paint(Graphics g) {
    g.setColor(Color.YELLOW);
    g.fillRect(0,0,getWidth(),getHeight());
  }
}
</sscce>

That is one nasty hack, straight out the door. :-)

Thanks!

--
Andrew T.
pscode.org