JSP学习笔记05-response

response.getOutputStream()

实例：验证码

public class CheckCode extends HttpServlet {

    /**
     *
     */
    private static final long serialVersionUID = 1L;
   
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        this.doPost(req, resp);
    }

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
       
        ServletContext sc = this.getServletContext();
        HttpSession session = req.getSession();
        resp.setContentType("image/jpeg");
        Random r = new Random();
        String i = String.valueOf(r.nextInt(10000));
        BufferedImage image = new BufferedImage(50, 20, BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        g.fillRect(0, 0, 50, 20);
        g.setColor(new Color(0,0,0));
        //g.setColor(new Color(255,0,0));
        g.setFont(new Font("Arial Black", Font.PLAIN, 15));
        g.drawString(i, 10, 13);
        g.dispose();
        ImageIO.write(image, "jpg", resp.getOutputStream());
        session.setAttribute("checkCode", i);
    }

   
}

response.sendRedirct();

response.addCookie()

request.getCookies()