Java Point1

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.Controller;

public class ImageController implements Controller {

 public ModelAndView handleRequest( HttpServletRequest request,HttpServletResponse response ) throws Exception {
   // 在内存中绘图:

        String code = String.valueOf((int)(Math.random() * 9000) + 1000);

        BufferedImage image = new BufferedImage

            (100, 50, BufferedImage. TYPE_INT_RGB);

        Graphics2D g = image.createGraphics();

        g.setColor(Color.GRAY);

        g.fillRect(0, 0, 100, 50);

        g.setColor(Color.RED);

        g.drawRect(0, 0, 99, 49);

        g.setColor(Color.BLACK);

        g.drawString(code, 20, 20);

        g.dispose();

        image.flush();

        // 设置ContentType:

        response.setContentType("image/jpeg");

        response.setHeader("Cache-Control", "no-cache");

        // 输出到ServletOutputStream:

        ServletOutputStream output = response.getOutputStream();

        ImageIO.write(image, "jpeg", output);

        return null;

    }

}