/**Servlet that dynamically genererates a jpeg image.
* Internet Programming 2 - Course
* @author Martin Carlsson
*/
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import java.awt.*;
import java.awt.image.*;
import java.util.*;
import com.sun.image.codec.jpeg.JPEGCodec;
import java.text.*;

public class GenerateGraphics extends HttpServlet {
    
    private int yPos = 40, xPos = 40, TEXT_SIZE = 24;
        
    public void doGet(HttpServletRequest req, HttpServletResponse res) throws IOException, ServletException {
      
        System.setProperty("java.awt.headless", "true");
        BufferedImage buffImg = new BufferedImage(250,100,BufferedImage.TYPE_INT_RGB);  
        Graphics2D g = buffImg.createGraphics();// draw3DRect(int x, int y, int width, int height, boolean raised) 
        g.setFont(new Font("Serif", Font.ITALIC,TEXT_SIZE)); 
        g.setColor(Color.RED);
        DateFormat f = DateFormat.getTimeInstance();
        g.drawString("Dynamic clock",xPos,yPos);
        g.setColor(Color.GREEN);        
        g.drawString(f.format(new Date()),xPos,yPos*2);
        
        //Encodes ands sends the buffered image
        ServletOutputStream sOs = res.getOutputStream();
        res.setContentType("image/jpeg");
        JPEGCodec.createJPEGEncoder(sOs).encode(buffImg);
        sOs.close();
    }
} // End class GenerateGraphics