Posted by Andriy on Sep 13, 2012; 2:41pm
URL: https://forum.jogamp.org/Make-screenshot-of-work-display-tp4026085p4026154.html

Good, this is code:
package test;

import java.awt.Frame;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.media.opengl.*;
import javax.media.opengl.awt.GLCanvas;
import com.jogamp.opengl.util.*;
import com.jogamp.opengl.util.awt.Screenshot;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;

public class JOGLCapture implements GLEventListener {

    private double theta = 0;
    private double s = 0;
    private double c = 0;

    public static void main(String[] args) {
        GLProfile glp = GLProfile.getDefault();
        GLCapabilities caps = new GLCapabilities(glp);
        GLCanvas canvas = new GLCanvas(caps);

        Frame frame = new Frame("AWT Window Test");
        frame.setSize(300, 300);
        frame.add(canvas);
        frame.setVisible(true);

        frame.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });

        canvas.addGLEventListener(new JOGLCapture());

        FPSAnimator animator = new FPSAnimator(canvas, 60);
        animator.add(canvas);
        animator.start();
    }

    @Override
    public void display(GLAutoDrawable drawable) {
        update();
        render(drawable);
          try
            {
                        BufferedImage tScreenshot = Screenshot.readToBufferedImage(0,0, 600, 600, false);
                        File tScreenCaptureImageFile = new File("/home/android/hello.png");
                        ImageIO.write(tScreenshot, "png", tScreenCaptureImageFile);
                        System.exit(0);
            }
            catch (IOException ioe)
            {
                System.out.println (ioe.getMessage ());
            }
    }

    @Override
    public void dispose(GLAutoDrawable drawable) {
    }

    @Override
    public void init(GLAutoDrawable drawable) {
    }

    @Override
    public void reshape(GLAutoDrawable drawable, int x, int y, int w, int h) {
    }

    private void update() {
        theta += 0.01;
        s = Math.sin(theta);
        c = Math.cos(theta);
    }

    private void render(GLAutoDrawable drawable) {
        GL2 gl = drawable.getGL().getGL2();

        gl.glClear(GL.GL_COLOR_BUFFER_BIT);

        // draw a triangle filling the window
        gl.glBegin(GL.GL_TRIANGLES);
        gl.glColor3f(1, 0, 0);
        gl.glVertex2d(-c, -c);
        gl.glColor3f(0, 1, 0);
        gl.glVertex2d(0, c);
        gl.glColor3f(0, 0, 1);
        gl.glVertex2d(s, -s);
        gl.glEnd();
    }
}

I have only a screen of java frame, and what about all desktop screenshot??