java - drawing your own buffered image on frame

Question

I have a buffered image with the sizes of my frame:

public BufferedImage img;
public static int WIDTH = 800;
public static int HEIGHT = 600;
img=new BufferedImage(WIDTH, HEIGHT,BufferedImage.TYPE_INT_RGB);

How can I draw it so I can see just a black image filling the frame? without using Canvas

I want to use only the drawImage function from graphics without using the paint or paintComponent functions

If it is possible, how can i assign an 1D array [WIDTH*HEIGHT] to that image?

SIMPLY: I want to create an image ,convert the values from an array to pixels (0=black,999999999=lightblue etc.) and draw it to the screen.

EDIT:

This is the code that does not work as expected (it should be a frame with a black drawn image on it) but is just a blank frame.Why the image is not added tot the frame?

  import javax.swing.*;

  import java.awt.Canvas;
  import java.awt.Graphics;
  import java.awt.image.BufferStrategy;
  import java.awt.image.BufferedImage;
  import java.awt.image.DataBufferInt;

  public class test extends Canvas{

public static JFrame frame;
public static int WIDTH = 800;
public static int HEIGHT = 600;

public test(){
    
}

public static void main(String[] a){
    
        test t=new test();
        frame = new JFrame("WINDOW");
        frame.add(t);
        frame.pack();
        frame.setVisible(true);
        frame.setSize(WIDTH, HEIGHT);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        t.start();
    
}

public void start(){
    
    BufferedImage img = new BufferedImage(WIDTH, HEIGHT,BufferedImage.TYPE_INT_RGB);
    int[] pixels = ((DataBufferInt)img.getRaster().getDataBuffer()).getData();
    boolean running=true;
    while(running){
        BufferStrategy bs=this.getBufferStrategy();
        if(bs==null){
            createBufferStrategy(4);
            return;
        }
        for (int i = 0; i < WIDTH * HEIGHT; i++)
            pixels[i] = 0;
        
        Graphics g= bs.getDrawGraphics();
        g.drawImage(img, 0, 0, WIDTH, HEIGHT, null);
        g.dispose();
        bs.show();
        
    }
}}

Answer 1

As far as I understand what you are trying to achieve (which is 'not a lot'), this might give you some tips. The construction of the frame and image still seems untidy to me, but have a look over this.

import java.awt.Graphics;
import java.awt.Image;
import java.awt.image.BufferStrategy;
import java.awt.image.BufferedImage;
import java.awt.image.DataBufferInt;
import javax.swing.*;

public class TestImageDraw {

    public static JFrame frame;
    BufferedImage img;
    public static int WIDTH = 800;
    public static int HEIGHT = 600;

    public TestImageDraw() {
    }

    public static void main(String[] a){

        TestImageDraw t=new TestImageDraw();

        frame = new JFrame("WINDOW");
        frame.setVisible(true);

        t.start();
        frame.add(new JLabel(new ImageIcon(t.getImage())));

        frame.pack();
//      frame.setSize(WIDTH, HEIGHT);
        // Better to DISPOSE than EXIT
        frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    }

    public Image getImage() {
        return img;
    }

    public void start(){

        img = new BufferedImage(WIDTH, HEIGHT,BufferedImage.TYPE_INT_RGB);
        int[] pixels = ((DataBufferInt)img.getRaster().getDataBuffer()).getData();
        boolean running=true;
        while(running){
            BufferStrategy bs=frame.getBufferStrategy();
            if(bs==null){
                frame.createBufferStrategy(4);
                return;
            }
            for (int i = 0; i < WIDTH * HEIGHT; i++)
                pixels[i] = 0;

            Graphics g= bs.getDrawGraphics();
            g.drawImage(img, 0, 0, WIDTH, HEIGHT, null);
            g.dispose();
            bs.show();

        }
    }
}

General Tips

• Please use a consistent and logical indent for code blocks.
• Please learn common Java naming conventions (specifically the case used for the names) for class, method & attribute names & use it consistently.
• Give test classes a meaningful name e.g. TestImageDraw.
• Create and update Swing GUIs on the EDT.
• Don't mix Swing & AWT components without good reason.