🚀 go-pugleaf

I have a NullPointerException error when the program executes the "g =
imagen.getGraphics()" sentence
in the constructor. This is not an applet. It's an application.
I tried this code alone with an Init method and occured the same error.
Can anybody help me with this?
thank you very much.


import java.io.*;
import java.awt.*;
import java.awt.Graphics;

public class MarcaGeneralCanvas extends Canvas {
  int fila, width, height;
  Image imagen;
  Graphics g;

  public MarcaGeneralCanvas(Marca marca) {
     imagen = this.createImage(400, 400);
     g = imagen.getGraphics();
.......
   }


  public void paint (Graphics g2) {
     g2.drawImage(Imagen,.....)
  .. ...
  }