How can I create an image with Java?

Question

I would like to create a gif image of a filled red circle on a green background. What is the easiest way to do it in Java?

Answer 1

Create a BufferedImage and then write it to a file with ImageIO.write(image, "gif", fileName).

Answer 2

If you already have an image file or image URL, then you can use Toolkit to get an Image:

Image img = Toolkit.getDefaultToolkit().createImage(filename);

If you need to construct a new image raster and paint into the image, then you can use BufferedImage. You can paint onto a BufferedImage, by calling its createGraphics function and painting on the graphics object. To save the BufferedImage into a GIF, you can use the ImageIO class to write out the image.

Answer 3

The best way is to generate a BufferedImage:

BufferedImage img = new BufferedImage(int width, int height, int imageType) 
// you can find the Types variables in the api

Then, generated the Graphics2D of this image, this object allows you to set a background and to draw shapes:

Graphics2D g = img.createGraphics();
g.setBackground(Color color) ; //Find how to built this object look at the java api
g.draw(Shape s);
g.dispose(); //don't forget it!!!

To built the image:

File file = new File(dir, name);
try{
  ImageIO.write(img, "gif", file);
}catch(IOException e){
  e.printStackTrace();
}