Jsp+servlet Implementing verification Code generation

The main use of jsp+servlet to achieve verification code generation

Asynchronous replacement of image address with jquery Ajax technology

BufferedImage implementation of verification code image generation

Servlet Code:

Package Register;import Java.awt.color;import java.awt.font;import java.awt.graphics;import Java.awt.image.bufferedimage;import Java.io.file;import Java.io.ioexception;import Java.util.Random;import Javax.imageio.imageio;import Javax.servlet.servletexception;import Javax.servlet.http.httpservlet;import Javax.servlet.http.httpservletrequest;import Javax.servlet.http.httpservletresponse;import javax.servlet.http.HttpSession;/** * Servlet implementation class GetCode*/ Public classGetCode extends HttpServlet {Private StaticFinalLongSerialversionuid =1L; /** * @see httpservlet#httpservlet ()*/     PublicGetCode () {super (); //TODO auto-generated Constructor stub    }    /** * @see httpservlet#doget (httpservletrequest request, httpservletresponse response)*/    protected voiddoget (httpservletrequest request, httpservletresponse response) throws Servletexception, IOException {//TODO auto-generated Method StubBufferedImage img =NewBufferedImage ( -, -, Bufferedimage.type_int_argb_pre); Graphics g=Img.getgraphics ();                              G.setcolor (Color.gray); G.fillrect (0,0, the, -);        Draw Verification Code Background g.setcolor (Color.White); G.setfont (NewFont ("Song Body", Font.Bold, -)); Random Rand=NewRandom (); String Code="";  for(intI=0;i<4; i++) {//randomly generate 4-bit digital CAPTCHA code+ = Rand.nextint (Ten); } g.drawstring (Code,5, -); Imageio.write (IMG,"PNG",NewFile ("d:/"+code+". PNG"));                 Generate a Captcha picture Response.getwriter (). println (code); Verification code back to foreground}/** * @see httpservlet#dopost (httpservletrequest request, httpservletresponse response)*/    protected voidDoPost (httpservletrequest request, httpservletresponse response) throws Servletexception, IOException {//TODO auto-generated Method Stubdoget (Request,response); }}

Front JSP page:

<%@ page language="Java"Contenttype="text/html; Charset=utf-8"pageencoding="Utf-8"%><! DOCTYPE HTML Public"-//w3c//dtd HTML 4.01 transitional//en" "HTTP://WWW.W3.ORG/TR/HTML4/LOOSE.DTD">"Content-type"Content="text/html; Charset=utf-8"><title>insert title Here</title><script type="Text/javascript"Src="Js/jquery-1.10.2.js"></script><script type="Text/javascript">$ (document). Ready (function () {varCode; $.ajax ({//Receive CAPTCHA URL:"GetCode", type:"POST", Success:function (data, textstatus) {code=$.trim (data); $("img"). attr ({src:"d:/"+code+". PNG"});            Change Captcha Address}, Error:function (XMLHttpRequest, Textstatus, Errorthrown) {}}); $("#img"). Click (function () {//img tag to bind a point click event, click Change Picture $.ajax ({url:"GetCode", type:"POST", Success:function (data, textstatus) {code=$.trim (data); $("img"). attr ({src:"d:/"+code+". PNG"});    }, Error:function (XMLHttpRequest, Textstatus, Errorthrown) {}});    }); $("#code"). blur (function () {//To determine if the input verification code and the generated consistencyif($("#code"). val ()! =code) {            $("#code"). CSS ("Background-color","#F00"); }        Else{            $("#code"). CSS ("Background-color","#0f0");    }                }); });</script>"#">Account&nbsp;&nbsp;&nbsp;&nbsp; No. <input type="text"Name="username"Id="username"/><br><br>Dense&nbsp;&nbsp;&nbsp;&nbsp; Code <input type="Password"Name="Password"Id="Password"/><br><br>Verification Code<input type="text"Name="Code"Id="Code"/>"img"Src="#"><br><br> <input type="Submit"Value="Register"> </form></body>
Jsp+servlet Implementing verification Code generation