Java-How to draw pixels on a screen

Question

What is the best way to simply print pixels onto a screen in Java, either through a simple loop or an array?

Answer 1

You can use a BufferedImage and display it on a JLabel. Something like:

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.List;
import javax.swing.*;

public class SSCCE extends JPanel
{
    public SSCCE()
    {
        int size = 300;
        BufferedImage bi = new BufferedImage(size, size, BufferedImage.TYPE_INT_RGB);
        ImageIcon icon = new ImageIcon( bi );
        add( new JLabel(icon) );

        for (int y = 0; y < size; y += 5)
        {
            for (int x = 0; x < size; x++)
            {
                Color color = (y % 2 == 0) ? Color.RED : Color.GREEN;
                int colorValue = color.getRGB();
                bi.setRGB(x, y, colorValue);
                bi.setRGB(x, y + 1, colorValue);
                bi.setRGB(x, y + 2, colorValue);
                bi.setRGB(x, y + 3, colorValue);
                bi.setRGB(x, y + 4, colorValue);
            }
        }
    }

    private static void createAndShowGUI()
    {
        JFrame frame = new JFrame("SSCCE");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add( new SSCCE() );
        frame.setLocationByPlatform( true );
        frame.pack();
        frame.setVisible( true );
    }

    public static void main(String[] args)
    {
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                createAndShowGUI();
            }
        });
    }
}

Or you can create a custom component and implement the paintComponent(...) method using methods from the Graphics class:

Graphics.fillRect(...);
Graphics.fillOval(...);
etc..

Read the section from the Swing tutorial on Custom Painting for more information and examples to get your started. Don't forget to read the Graphics API for other Graphics methods.