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displaying pictures side by side in java

is it possible to display two pictures, next to each other with BufferedImage and Graphics2D ? or should I do it with other method ?
In my code below, I was able to display two images, but the picture 1 overlaps to the picture 2.
package zdjecie;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JPanel;
public class ObrazPanel extends JPanel {
private BufferedImage image;
private BufferedImage image2;
public ObrazPanel() {
super();
File imageFile = new File("C:\\Users\\KostrzewskiT\\eclipse-workspace\\zdjecie\\src\\zdjecie\\java.jpg");
File imageFile2 = new File("C:\\Users\\KostrzewskiT\\eclipse-workspace\\zdjecie\\src\\zdjecie\\java2.jpg");
try {
image = ImageIO.read(imageFile);
image2 = ImageIO.read(imageFile2);
} catch (IOException e) {
System.err.println("Blad odczytu obrazka");
e.printStackTrace();
}
Dimension dimension = new Dimension(image.getWidth(), image.getHeight());
setPreferredSize(dimension);
Dimension dimension2 = new Dimension(image2.getWidth(), image2.getHeight());
setPreferredSize(dimension2);
}
#Override
public void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(image, 0, 0, this);
g2d.drawImage(image2, 200, 200, this);
}
}

You call setPreferredSize twice, which results in the first call doing basically nothing. That means you always have a preferredSize equal to the dimensions of the second image. What you should do is to set the size to new Dimension(image.getWidth() + image2.getWidth(), image2.getHeight()) assuming both have the same height. If that is not the case set the height as the maximum of both images.
Secondly you need to offset the second image from the first image exactly by the width of the first image:
g2d.drawImage(image, 0, 0, this);
g2d.drawImage(image2, image.getWidth(), 0, this);

The logic of the math was incorrect. See the getPreferredSize() method for the correct way to calculate the required width, and the changes to the paintComponent(Graphics) method to place them side-by-side.
An alternative (not examined in this answer) is to put each image into a JLabel, then add the labels to a panel with an appropriate layout.
This is the effect of the changes:
import java.awt.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
import java.net.*;
import javax.imageio.ImageIO;
public class ObrazPanel extends JPanel {
private BufferedImage image;
private BufferedImage image2;
public ObrazPanel() throws MalformedURLException {
super();
URL imageFile = new URL("https://i.stack.imgur.com/7bI1Y.jpg");
URL imageFile2 = new URL("https://i.stack.imgur.com/aH5zB.jpg");
try {
image = ImageIO.read(imageFile);
image2 = ImageIO.read(imageFile2);
} catch (Exception e) {
System.err.println("Blad odczytu obrazka");
e.printStackTrace();
}
}
#Override
public Dimension getPreferredSize() {
int w = image.getWidth() + image2.getWidth();
int h1 = image.getHeight();
int h2 = image2.getHeight();
int h = h1>h2 ? h1 : h2;
return new Dimension(w,h);
}
#Override
public void paintComponent(Graphics g) {
// always best to start with this..
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.drawImage(image, 0, 0, this);
g2d.drawImage(image2, image.getWidth(), 0, this);
}
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (Exception useDefault) {
}
ObrazPanel o;
try {
o = new ObrazPanel();
JFrame f = new JFrame(o.getClass().getSimpleName());
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.setLocationByPlatform(true);
f.setContentPane(o);
f.pack();
f.setMinimumSize(f.getSize());
f.setVisible(true);
} catch (MalformedURLException ex) {
ex.printStackTrace();
}
}
};
SwingUtilities.invokeLater(r);
}
}

I would join the images whenever something changes and draw them to another buffered image. Then I can just redraw the combined image whenever the panel needs to be redrawn.
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.*;
public class SideBySideImagePanel extends JPanel {
private static final long serialVersionUID = 5868633578732134172L;
private BufferedImage left;
private BufferedImage right;
private BufferedImage join;
public SideBySideImagePanel() {
ClassLoader loader = this.getClass().getClassLoader();
BufferedImage left = null, right = null;
try {
left = ImageIO.read(loader.getResourceAsStream("resources/Android.png"));
right = ImageIO.read(loader.getResourceAsStream("resources/Java.png"));
} catch (IOException e) {
e.printStackTrace();
}
this.setLeft(left);
this.setRight(right);
}
public BufferedImage getLeft() {
return left;
}
public void setLeft(BufferedImage left) {
this.left = left;
}
public BufferedImage getRight() {
return right;
}
public void setRight(BufferedImage right) {
this.right = right;
}
#Override
public void invalidate() {
super.invalidate();
join = combineImages(left, right);
setPreferredSize(new Dimension(join.getWidth(), join.getHeight()));
}
#Override
public void paintComponent(Graphics g) {
g.drawImage(join, 0, 0, null);
}
private BufferedImage combineImages(BufferedImage left, BufferedImage right) {
int width = left.getWidth() + right.getWidth();
int height = Math.max(left.getHeight(), right.getHeight());
BufferedImage combined = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
Graphics g = combined.getGraphics();
g.drawImage(left, 0, 0, null);
g.drawImage(right, left.getWidth(), 0, null);
return combined;
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
JFrame frame = new JFrame("Image Joiner");
SideBySideImagePanel panel = new SideBySideImagePanel();
frame.getContentPane().add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.pack();
frame.setVisible(true);
}
});
}
}

I found some errors in your code and I did not got what are you trying to do...
1] Over there you are actually not using the first setup
Dimension dimension = new Dimension(image.getWidth(), image.getHeight());
setPreferredSize(dimension); //not used
Dimension dimension2 = new Dimension(image2.getWidth(), image2.getHeight());
setPreferredSize(dimension2); //because overridden by this
It means, panel is having dimensions same as the image2, you should to set it as follows:
height as max of the heights of both images
width at least as summarize of widths of both pictures (if you want to paint them in same panel, as you are trying)
2] what is the image and image2 datatypes? in the block above you have File but with different naming variables, File class ofcourse dont have width or height argument
I am assuming its Image due usage in Graphics.drawImage, then:
You need to setup preferred size as I mentioned:
height to max value of height from images
width at least as summarize value of each widths
Dimensions things:
Dimension panelDim = new Dimension(image.getWidth() + image2.getWidth(),Math.max(image.getHeight(),image2.getHeight()));
setPreferredSize(panelDim)
Then you can draw images in the original size
- due coordinates are having 0;0 in the left top corner and right bottom is this.getWidth(); this.getHeight()
- check eg. this explanation
- you need to start paint in the left bottom corner and then move to correct position increase "X" as the width of first image
#Override
public void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D) g;
/* public abstract boolean drawImage(Image img,
int x,
int y,
Color bgcolor,
ImageObserver observer)
*/
//start to paint at [0;0]
g2d.drawImage(image, 0, 0, this);
//start to paint just on the right side of first image (offset equals to width of first picture)- next pixel on the same line, on the bottom of the screen
g2d.drawImage(image2,image2.getWidth()+1, 0, this);
}
I didn't had a chance to test it, but it should be like this.
Important things are
you need to have proper dimensions for fitting both images
screen coordinates starts in the left top corner of the screens [0;0]

image.setRGB() not working as intended

I'm trying to make my own, very inefficient "image copier". I'm doing it by reading the pixels from the original image on to an array and then resetting those same pixels in my default BufferedImage. And then repaint the frame. Row by row.
I'm trying to repaint the frame every after each row of pixels has been stored in the array. But the frame only gets updated once; when it finishes storing the pixels.
My code is all over the place, and I'm probably doing a lot of stuff wrong. This is for an assignment and I've been going at it for a while now and would really appreciate some help.
Here is my code:
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;
import java.awt.*;
import javax.swing.JComponent;
import javax.swing.JFrame;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class pixelReloc extends JComponent {
static BufferedImage image,newImg;
static JFrame frame;
public void initialize() {
int width = getSize().width;
int height = getSize().height;
int pixels[];
int index = 0;
int j=0,i=0;
File f = new File("/path/to/file/images/shrek4life.jpg");
try{
image = ImageIO.read(f);
}catch(IOException e){}
System.out.println("checkpoint 1");
image = createResizedCopy(image,500,500,true);
newImg = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_RGB);
pixels = new int[(image.getWidth()) * (image.getHeight())];
System.out.println("checkpoint 2");
for(i= 0; i < newImg.getWidth(); i++){
for(j = 0; j < newImg.getHeight(); j++){
//get the rgb color of the old image
Color c = new Color(image.getRGB(i, j));
int r = c.getRed();
int g = c.getGreen();
int b = c.getBlue();
pixels[index++] = (r<<16) | (g<<8) | b;
}
newImg.setRGB(0, 0, i, j, pixels, 0, 0);
frame.getContentPane().validate();
frame.getContentPane().repaint();
}
System.out.println("checkpoint 4");
//image.setRGB(0, 0, width, height, data, 0, width);
}
public BufferedImage createResizedCopy(BufferedImage originalImage,
int scaledWidth, int scaledHeight,
boolean preserveAlpha)
{
System.out.println("resizing...");
int imageType = preserveAlpha ? BufferedImage.TYPE_INT_RGB : BufferedImage.TYPE_INT_ARGB;
BufferedImage scaledBI = new BufferedImage(scaledWidth, scaledHeight, imageType);
Graphics2D g = scaledBI.createGraphics();
if (preserveAlpha) {
g.setComposite(AlphaComposite.Src);
}
g.drawImage(originalImage, 0, 0, scaledWidth, scaledHeight, null);
g.dispose();
return scaledBI;
}
public void paint(Graphics g) {
if (image == null)
initialize();
g.drawImage(newImg, 0, 0, this);
}
public static void main(String[] args) {
frame = new JFrame("P I X E L S");
frame.getContentPane().add(new pixelReloc ());
frame.setSize(500, 500);
frame.setLocation(100, 100);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
frame.setVisible(true);
}
}
Here is the picture I'm reading the pixels from:
and this is how it's coming out:
The program doesn't give any errors or anything.

The basic answer to your question is, you're blocking the Event Dispatching Thread.
Swing is both single threaded and NOT thread safe. This means you can't run long running or blocking operations from within the EDT AND you should't not update the UI or some state the UI depends on from outside the EDT.
I recommend that you start by having a look at Concurrency in Swing.
This leaves with three basic options:
Use another Thread. This is problematic as you need to ensure that any state that the UI relies on is only updated from within the context of the EDT
Use a SwingWorker. This is basically the previous option, but with built in management which allows you to publish updates which are process'ed on the EDT
Use a Swing Timer. In your case, this is probably not the best solution, but it is the simplest.
For example
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.SwingWorker;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new PixelReloc());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class Pixel {
private int x, y;
private int color;
public Pixel(int x, int y, int color) {
this.x = x;
this.y = y;
this.color = color;
}
public int getX() {
return x;
}
public int getY() {
return y;
}
public int getColor() {
return color;
}
}
public class PixelReloc extends JComponent {
private BufferedImage image;
private BufferedImage newImg;
public PixelReloc() {
SwingWorker<Integer[], List<Pixel>> worker = new SwingWorker<Integer[], List<Pixel>>() {
Integer pixels[];
#Override
protected Integer[] doInBackground() throws Exception {
pixels = new Integer[image.getWidth() * image.getHeight()];
int index = 0;
List<Pixel> pixies = new ArrayList<>(image.getWidth());
for (int y = 0; y < image.getHeight(); y++) {
for (int x = 0; x < image.getWidth(); x++) {
int color = image.getRGB(x, y);
pixels[index++] = color;
pixies.add(new Pixel(x, y, color));
}
publish(new ArrayList<Pixel>(pixies));
pixies = new ArrayList<>(image.getWidth());
Thread.sleep(100);
}
return pixels;
}
#Override
protected void process(List<List<Pixel>> chunks) {
for (List<Pixel> pixels : chunks) {
for (Pixel pixel : pixels) {
newImg.setRGB(pixel.getX(), pixel.getY(), pixel.getColor());
}
}
repaint();
}
};
File f = new File("/Volumes/Big Fat Extension/Dropbox/MegaTokyo/chaotic_megatokyo_by_fredrin-d9k84so.jpg");
try {
image = ImageIO.read(f);
} catch (IOException e) {
}
System.out.println("checkpoint 1");
image = createResizedCopy(image, 200, 200, true);
newImg = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_ARGB);
worker.execute();
// pixels = new int[(image.getWidth()) * (image.getHeight())];
// System.out.println("checkpoint 2");
// for (i = 0; i < newImg.getWidth(); i++) {
// for (j = 0; j < newImg.getHeight(); j++) {
// //get the rgb color of the old image
// Color c = new Color(image.getRGB(i, j));
// int r = c.getRed();
// int g = c.getGreen();
// int b = c.getBlue();
// pixels[index++] = (r << 16) | (g << 8) | b;
// }
// }
// System.out.println("checkpoint 4");
//image.setRGB(0, 0, width, height, data, 0, width);
}
#Override
public Dimension getPreferredSize() {
return image == null ? new Dimension(200, 200) : new Dimension(image.getWidth(), image.getHeight());
}
public BufferedImage createResizedCopy(BufferedImage originalImage,
int scaledWidth, int scaledHeight,
boolean preserveAlpha) {
System.out.println("resizing...");
Image scaled = originalImage.getScaledInstance(scaledWidth, -1, Image.SCALE_SMOOTH);
BufferedImage scaledBI = new BufferedImage(scaled.getWidth(null), scaled.getHeight(null), BufferedImage.TYPE_INT_ARGB);
Graphics2D g = scaledBI.createGraphics();
g.drawImage(scaled, 0, 0, null);
g.dispose();
return scaledBI;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(newImg, 0, 0, this);
}
}
}
The Thread.sleep in the SwingWorker is intended to do two things:
Give time for the EDT to process the results from the process call and
Slow down the worker so that the results can be updated on the UI.
In my testing without it, the image was pretty much updated instantly.
I also recommend you take the time to better understand the paint process in Swing, start by having a look at:
Performing Custom Painting
Painting in AWT and Swing
The scaling mechanism you were using (and the one I've implemented) aren't the best solutions. I recommend having look at:
Java: maintaining aspect ratio of JPanel background image
Quality of Image after resize very low -- Java
for some better ideas.

You made a couple of mistakes, the first one is using 0 as scansize which should be the width of the image, also in the same line you should use the width and height instead of i and j.
newImg.setRGB(0, 0, image.getWidth(), image.getHeight(), pixels, 0, image.getWidth());
There is one other mistake which I will let you find on your own, it should be obvious after you see the image with the above fixed line.

How to edit the pixels in a BufferedImage?

After scouring the internet for days, I found a Question that seemed to address my goal. (I'm trying to draw/edit an individual pixel in an image, and render it.) In said question, The ask-er requested code for a Black BufferedImage. The top Answer provided that code, and appears to work beautifully, until you try to change it to something other than black. Here's the Code:
package myProjectPackage;
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 Copypasta {
public static JFrame frame;
BufferedImage img;
public static int WIDTH = 500;
public static int HEIGHT = 500;
public Copypasta() {
}
public static void main(String[] a){
Copypasta t=new Copypasta();
frame = new JFrame("WINDOW");
frame.setVisible(true);
t.start();
frame.add(new JLabel(new ImageIcon(t.getImage())));
frame.pack();
// 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; //This is what i've been trying to change.
Graphics g= bs.getDrawGraphics();
g.drawImage(img, 0, 0, WIDTH, HEIGHT, null);
g.dispose();
bs.show();
}
}
}
I Apologize for the indentation errors. I promise it looks right in the editor.
When set to BufferedImage type ARGB, the black background disappears, causing me to believe that the start function isn't drawing to the Image at all, or the drawn image is not being drawn on the screen. Either way, There is something that I don't understand. If you have the time, I would appreciate some help Identifying What is going wrong, if not an explanation of why. Thank you all,
-Navi.
Link to Original Question: drawing your own buffered image on frame

Several things jump out, the use of BufferStrategy is probably overkill. Unless you absolutely must have control over the paint process, you really don't need it. Using a BufferStrategy also precludes the use of Swing based components which might or might not be an issue.
Trying to manipulate the pixel data directly is probably also a little overkill, instead you can use BufferedImage.setRGB(int, int, int), which allows you to set the color of the pixel at the specified x/y position, for example...
img = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < img.getWidth(); x++) {
for (int y = 0; y < img.getHeight(); y++) {
img.setRGB(x, y, Color.RED.getRGB());
}
}
But, even this is a little overkill, the same thing can be achieved by using the provided 2D Graphics API...
Graphics2D g2d = img.createGraphics();
g2d.setColor(Color.RED);
g2d.fillRect(0, 0, img.getWidth(), img.getHeight());
g2d.dispose();
Which you will probably find is faster (not just from a coding point of view).
Take a look at:
Performing Custom Painting
Painting in AWT and Swing
2D Graphics
For more details...
Working example...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestImage1 {
public static void main(String[] args) {
new TestImage1();
}
public TestImage1() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private BufferedImage img;
public TestPane() {
img = new BufferedImage(100, 100, BufferedImage.TYPE_INT_RGB);
//for (int x = 0; x < img.getWidth(); x++) {
// for (int y = 0; y < img.getHeight(); y++) {
// img.setRGB(x, y, Color.RED.getRGB());
// }
//}
Graphics2D g2d = img.createGraphics();
g2d.setColor(Color.RED);
g2d.fillRect(0, 0, img.getWidth(), img.getHeight());
g2d.dispose();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(img, 0, 0, this);
g2d.dispose();
}
}
}

Unable Take screenshot of JFrame Java Swing

I have tried to save the JFrame as an image using the following approach.
try
{
BufferedImage image = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);
this.paint(image.getGraphics());
ImageIO.write(image,"png", new File("Test.png"));
}
catch(Exception exception)
{
//code
System.out.print("Exception unable to write image");
}
I am trying to save a screenshot as follows:
I would like to have even the title in my screenshot
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class DividedSquare {
public static void main(String[] args) {
new DividedSquare();
}
public DividedSquare() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private TriangleShape baseTriangle;
private Color[] colors;
public TestPane() {
colors = new Color[]{Color.RED, Color.GREEN, Color.BLUE, Color.MAGENTA};
}
#Override
public void invalidate() {
super.invalidate();
baseTriangle = new TriangleShape(
new Point(0, 0),
new Point(getWidth(), 0),
new Point(getWidth() / 2, getHeight() / 2));
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
String text[] = new String[]{
"123.123",
"456.789",
"012.315",
"678.921"
};
FontMetrics fm = g2d.getFontMetrics();
double angel = 0;
for (int index = 0; index < 4; index++) {
g2d.setColor(colors[index]);
Path2D rotated = rotate(baseTriangle, angel);
g2d.fill(rotated);
Rectangle bounds = rotated.getBounds();
int x = bounds.x + ((bounds.width - fm.stringWidth(text[0])) / 2);
int y = bounds.y + (((bounds.height - fm.getHeight()) / 2) + fm.getAscent());
g2d.setColor(Color.WHITE);
g2d.drawString(text[index], x, y);
angel += 90;
}
g2d.setColor(Color.BLACK);
g2d.drawLine(0, 0, getWidth(), getHeight());
g2d.drawLine(getWidth(), 0, 0, getHeight());
g2d.dispose();
try
{
BufferedImage image = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_RGB);
frame.paint(image.getGraphics());
ImageIO.write(image,"png", new File("Practice.png"));
}
catch(Exception exception)
{
//code
System.out.print("Exception to write image");
}
}
public Path2D rotate(TriangleShape shape, double angel) {
Rectangle bounds = shape.getBounds();
int x = bounds.width / 2;
int y = bounds.width / 2;
return new Path2D.Float(shape, AffineTransform.getRotateInstance(
Math.toRadians(angel),
x,
y));
}
}
public class TriangleShape extends Path2D.Double {
public TriangleShape(Point2D... points) {
moveTo(points[0].getX(), points[0].getY());
lineTo(points[1].getX(), points[1].getY());
lineTo(points[2].getX(), points[2].getY());
closePath();
}
}
}
But I the image does not get created. I am unable to understand why.
I looked at this but am unable to understand how to incorporate it in my case.
Edit
Based on comments, I tried using robot class but am unable to know where to call this function from. If I call this function from the paint() method, I am unable to get the colors and text.
void screenshot()
{
try
{
Robot robot = new Robot();
// Capture the screen shot of the area of the screen defined by the rectangle
Point p = frame.getLocationOnScreen();
System.out.print("point" + p);
BufferedImage bi=robot.createScreenCapture(new Rectangle((int)p.getX(),(int)p.getY(),frame.getWidth(),frame.getHeight()));
ImageIO.write(bi, "png", new File("imageTest.png"));
}
catch(Exception exception)
{
//code
System.out.print("Exception to write image");
}
}

There are at least two ways you might achieve this...
You Could...
Use Robot to capture a screen shot. For example
The problem with this is it takes a little effort to target the component you want to capture. It also only captures a rectangular area, so if the component is transparent, Robot won't respect this...
You Could...
Use printAll to render the component to your own Graphics context, typically from a BufferedImage
printAll allows you to print a component, because the intention is not to print this to the screen, printAll disables double buffering, making it more efficient to use when you don't want to render the component to the screen, such printing it to a printer...
Forexample

You can use Robot to capture screenshot. But it not gives Jframe Screenshot. We need to give correct coordinates and refer the frame. gFrame is my frame name and below code works for only Jframe area screenshot.
try {
Robot cap=new Robot();
Rectangle rec=new Rectangle(gFrame.getX(),gFrame.getY(),gFrame.getWidth(),gFrame.getHeight());
BufferedImage screenshot=cap.createScreenCapture(rec);
ImageIO.write(screenshot, "JPG",
new File("C:\\Users\\ruwan\\Downloads\\screenshot.jpg");
} catch (Exception e) {
e.printStackTrace();
}

Having trouble displaying graphics in Swing

I've been trying to visually simulate a traffic problem, but for some reason I get only blank output in my swing window. Instead of a constantly-moving picture with vehicles, I get only a grey screen.
My drawing class looks as follows:
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JPanel;
public class RoadNetwork extends JPanel {
BufferedImage tempicon = ImageIO.read(getClass().getResource("Truck.png"));
BufferedImage truckicon = new BufferedImage(tempicon.getWidth(), tempicon.getHeight(), BufferedImage.TYPE_INT_ARGB);
public RoadNetwork() throws IOException {
repaint();
}
protected void paintComponent (Graphics g) {
super.paintComponent(g);
g.clearRect(0, 0, 600, 600); // insert window size parameters here
for (int i = 0; i < AMEC.vehiclecounter; i++) {
if (AMEC.vehicle[i].spawned == true && AMEC.vehicle[i].finished == false) { // if the truck is somewhere on the plant
g.drawImage(truckicon, AMEC.getcoord(i)[0], AMEC.getcoord(i)[1], this);
}
}
g.drawImage(truckicon, 100, 100, this);
}
}
The call to the class in my main function is done as follows:
RoadNetwork roadnetwork = new RoadNetwork();
roadnetwork.setVisible(true);
JFrame frame = new JFrame();
frame.add(roadnetwork);
frame.setSize(600, 600);
frame.setVisible(true);
Then, with every iteration of my simulation, I call
roadnetwork.repaint();
What am I missing?

BufferedImage tempicon = ImageIO.read(getClass().getResource("Truck.png"));
BufferedImage truckicon = new BufferedImage(tempicon.getWidth(), tempicon.getHeight(), BufferedImage.TYPE_INT_ARGB);
At the end of the 2nd code line, truckicon is still completely invisible (since it is a transparent image that we have drawn nothing to). Try instead.
BufferedImage truckicon = ImageIO.read(getClass().getResource("Truck.png"));

I hate not knowing why something works. But I remember going through the Graphics totorial and seeing them do this in the constructor where they seem to draw the second image
BufferedImage img = ImageIO.read(imageSrc);
int w = img.getWidth(null);
int h = img.getHeight(null);
BufferedImage bi = new
BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics g = bi.getGraphics();
g.drawImage(img, 0, 0, null);
Here's the fix I made. I wish I could give more explanation, but feel free to check out the tutorial I linked
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class RoadNetwork extends JPanel {
BufferedImage tempicon;
BufferedImage truckicon;
public RoadNetwork() throws IOException {
tempicon = ImageIO.read(getClass().getResource("resources/stack_reverse.png"));
int w = tempicon.getWidth(null);
int h = tempicon.getHeight(null);
truckicon = new
BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics g = truckicon.getGraphics();
g.drawImage(tempicon, 0, 0, null);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
//g.clearRect(0, 0, 600, 600); // insert window size parameters here
// for (int i = 0; i < AMEC.vehiclecounter; i++) {
// if (AMEC.vehicle[i].spawned == true && AMEC.vehicle[i].finished ==
// false) { // if the truck is somewhere on the plant
// g.drawImage(truckicon, AMEC.getcoord(i)[0], AMEC.getcoord(i)[1],
// this);
// }
// }
g.drawImage(truckicon, 100, 100, this);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable(){
public void run() {
try {
RoadNetwork roadnetwork = new RoadNetwork();
roadnetwork.setVisible(true);
JFrame frame = new JFrame();
frame.add(roadnetwork);
frame.setSize(600, 600);
frame.setVisible(true);
} catch (IOException es) {
es.printStackTrace();
}
}
});
}
}
Also, I was going to suggest #AndrewThompson's answer, but because I didn't know the reason you were using two BufferedImages, I didn't want to suggest it. You may have been trying to do what the tutorial was doing.