Java Verification Code Learning one

Package Com.sys.web.sesoion;import Java.io.ioexception;import Java.io.printwriter;import Javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;import Java.awt.Graphics; Import Java.awt.image.bufferedimage;import Java.util.random;import Javax.imageio.imageio;import Javax.servlet.http.httpsession;public class Checkcodeservlet extends HttpServlet {public void doget ( HttpServletRequest request, HttpServletResponse response) throws Servletexception, IOException {bufferedimage image = NE W BufferedImage (50,25,BUFFEREDIMAGE.TYPE_INT_RGB); Graphics g = image.getgraphics (); g.DrawString (Token.getnum (), 15,15); Imageio.write (Image, "JPG", Response.getoutputstream ()); Response.setheader ("Expires", "1"); Response.setheader ("Cache-control", "No-cache"); No slow into response.setheader ("Pragma", "no-cache"); }}//is used to generate a random number class token{public static String Getnum () {Random r = new Random (); int num = R.nextint (10000); return num + "";}}

Java Verification Code Learning one