Thread: Newb Java Problem - non-static method cannot be accessed from static context

Any Java Gurus out there that can help a newbie?

I'm trying to create a program to write a png and jpeg file from an image I create. I'm getting the usual "non-static method cannot be accessed by static context" error. I know the general explanation is that I'm trying to access a method without creating a new instance of it. However, I thought one of my alternate solutions would solve the problem - but they don''t.

Here's the code:

import java.awt.image.BufferedImage;
import java.io.*;
import java.awt.Graphics2D;
import java.awt.image.RenderedImage;
import javax.imageio.ImageIO;
import java.awt.Color;
 
 
public class WriteText_PicTest {
 
    public RenderedImage myCreateImage()
        {
        int width = 100; int height = 100;
 
        // Create a buffered image in which to draw
        BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
 
        // Create a graphics contents on the buffered image
        Graphics2D g2d = bufferedImage.createGraphics();
 
        // Draw graphics
 
        g2d.setColor(Color.white);
        g2d.fillRect(0, 0, width, height);
        g2d.setColor(Color.black);
        g2d.fillOval(0, 0, width, height);
 
        // Graphics context no longer needed so dispose it
        g2d.dispose();
        return bufferedImage;
    }
 
        public static void main (String args[])
    {
 
        // Create an image to save
 
RenderedImage rendImage = myCreateImage();
 
// Write generated image to a file
 
        try {
            // Save as PNG File
            File file = new File("newimage.png");
            ImageIO.write(rendImage, "png", file);
 
            // Save as JPEG
            file = new File("newimage.jpg");
            ImageIO.write(rendImage, "jpg", file);
 
        } catch (IOException e) { }
    }
 
    // Returns a generated image.
 
 
}

Here's what I've tried (and what has failed). It says it cannot find the symbol myCreateImage

changing:

RenderedImage rendImage = myCreateImage();

to

RenderedImage rendImage = new myCreateImage();

or

RenderedImage rendImage = new rendImage.myCreateImage();

or

RenderedImage rendImage = rendImage.myCreateImage();

Any help anyone could give me (especially an explantion why a new instance isn't created) would be appreciated.

That did the trick, HelloWorld.

Do you happen to know why the method needs to be static?

Do you happen to know why the method needs to be static?

That's why I posted a link.

Man, that is the one problem that almost everyone has when they start Java. It is a very confusing error when you first start. It took me forever to even understand what it meant when I first started.

I've never had the problem, but I was taught that.

Sorry BRT93! Let me know if this is should be asked in the Java theory forum.

I followed the links and have a couple of questions to make sure I understand it correctly.

Do all methods within a Class with a "main" block have to be static? And, any methods created as part of other objects do not need to be static. However, if an instance of that object is created in the main block the method is accessed by fully qualifying the reference (e.g. Bicycles.numberOfBicycles).

If so, why can't a main directly reference a method within it's own class? Is it just one of those java things?

AUSSIEMCGR - thank you so much. I'm sure I read that somewhere, but it didn't sink in until you explained it. Thanks again.

i'm going to do some reading and I might be back. I'm trying to figure out when a method wouldn't have to be static.

Thanks again!

@TedVon, sorry that I didn't respond. I was on a road trip. Thank you very much AussieMCGR for finishing the topic.