import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.font.LineMetrics;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;



// Image scaling :http://helpdesk.objects.com.au/java/how-do-i-scale-a-bufferedimage 
public class ImageServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
	
	Logger logger = Logger.getLogger(ImageServlet.class.getName());
       
	protected Font loadFont() throws  IOException {
		File fontFile= new File( getServletContext().getRealPath("/Comic_Sans_MS.ttf") );
		logger.info( "Font:" + fontFile.getAbsolutePath() );

		Font font = null;
		try {
			font = Font.createFont(Font.TRUETYPE_FONT, fontFile);
		} catch (Exception ex) {
			logger.log(Level.SEVERE, "Font load failed", ex);
		}
		
		
		return font.deriveFont(48.0f);
	}

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		final int width = 400;
		final int height = 400;
		BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		
		Graphics2D gfx = bufferedImage.createGraphics();
		gfx.setColor( Color.white ); 
		gfx.fillRect(0, 0, width, height); //Graphics2D has many various drawing methods
		gfx.setColor( Color.blue );
		gfx.fillOval(10, 10, width-20, height-20);
		gfx.setColor( Color.black );
		
		/////////////////////
		///Text draw section
		String text = "Text to draw";
		Font f = loadFont();
		gfx.setFont( f );		
		Rectangle2D bounds = f.getStringBounds(text, gfx.getFontRenderContext());
		int textX = (int) (width-bounds.getWidth())/2;
		
		
		logger.info("bWidth=" + bounds.getWidth() + ", bHeight=" + bounds.getHeight());
		
		
		gfx.drawString(text, textX, 210);//note that the Y denotes the text's baseline !
		
		
		
		gfx.dispose(); //dispose when we are done with drawing
		
		
		//Downscale image to create a smoother looking one
		BufferedImage smallImage = new BufferedImage(width/2, height/2, BufferedImage.TYPE_INT_RGB);
		gfx = smallImage.createGraphics();
		gfx.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
		gfx.drawImage(bufferedImage, 0, 0, width/2, height/2, null);
		gfx.dispose();
		
		
		
		response.setContentType("image/png");
		ImageIO.write(smallImage, "png", response.getOutputStream() ); // use imageio.read to load a file to a bufferedimage
		
	}

}