Jsp-5 Generate verification code and verify

Jsp-5 Generate verification code and verify

The last code is still the base

index.jsp

Added Verification code column

Note that his servlet is a new imageservlet.

And in the middle of a JS code to refresh the verification code

<%@ page language= "java" contenttype= "text/html; Charset=utf-8 "pageencoding= "UTF-8"%><%String Path=Request.getcontextpath (); String BasePath= Request.getscheme () + "://" +request.getservername () + ":" +request.getserverport () +path;%><! DOCTYPE HTML PUBLIC "-//w3c//dtd HTML 4.01 transitional//en" "Http://www.w3.org/TR/html4/loose.dtd" >String username=""; String Password="";//Remove CookiesCookie [] cookie=request.getcookies (); for(inti=0;i<cookie.length;i++){  if(Cookie[i].getname (). Equals ("username") ) {username=Cookie[i].getvalue (); }  if(Cookie[i].getname (). Equals ("Password") ) {Password=Cookie[i].getvalue (); }}%><script type= "Text/javascript" >//can't see the click events of overloaded picturesfunctionReloadcode () {varTime=NewDate (). GetTime (); document.getElementById ("Imagecode"). src= "<%= Request.getcontextpath ()%>/imageservlet?d=" +Time ;}</script><form action= "<%=basepath%>/login.do" method= "POST" > <table border=0 cellpadding=0 Cellspacing=0 style= "margin:auto;border-collapse:separate; border-spacing:10px; "            > <tr align= "center" > <td colspan= "2" > <label> login </label> </td> </tr> <tr> <td>User name:</td> <td> <input type= "text" name= "username" value= "<%=username%>" > </td> </tr> <tr> <td>Password:</td> <td> <input type= "password" name= "password" value= "<%=password%>"            ; </td> </tr> <tr> <td>Verification Code:</td> <td> <input type= "text" name= "Checkcode"/> /imageservlet "/><a href=" Javascript:reloadcode (); "                > Can't see clearly </a><br> </td> </tr> <tr> <td>            <input type= "checkbox" Name= "Ischeck" > Remember me? </td> <td> &nbsp;&nbsp;<a href= "<%=basepath%>/toregister.do" > Registration &                lt;/a> </td> </tr> <tr align= "center" > <td> <input type= "Submit" value= "Login" > </td> <td> <input type= "Reset" value= "Reset" > </td> </tr> </table></form></body>
Imageservlet class
Or that one, in theory, someone must have written the bag for us.
But I didn't find it.
ha haha haha ha ha haha
 Packagecom.javaweb.action;ImportJava.awt.Color;ImportJava.awt.Graphics;ImportJava.awt.image.BufferedImage;Importjava.io.IOException;ImportJava.util.Random;ImportJavax.imageio.ImageIO;Importjavax.servlet.ServletException;ImportJavax.servlet.http.HttpServlet;Importjavax.servlet.http.HttpServletRequest;ImportJavax.servlet.http.HttpServletResponse; Public classImageservletextendshttpservlet{/**     *      */    Private Static Final LongSerialversionuid = 54354321L; @Overrideprotected voidDoget (httpservletrequest req, HttpServletResponse resp)throwsservletexception, IOException {//TODO auto-generated Method StubdoPost (req, resp); }     Public voidDoPost (httpservletrequest request,httpservletresponse response)throwsioexception{//This method implements the verification code generationBufferedImage bi=NewBufferedImage (22,BUFFEREDIMAGE.TYPE_INT_RGB);//Creating an image bufferGraphics G=bi.getgraphics ();//Create a canvas from a bufferColor c=NewColor (200,150,255);//Create color         /** Draw a rectangle based on the background*/G.setcolor (c);//add a background color to the canvasG.fillrect (0, 0, 68,22);//FillRect: Fills the specified rectangle                  Char[] ch= "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789". ToCharArray ();//an array converted to a character typeRandom r=NewRandom (); intlen=ch.length; intIndex//index is used to store random numbersStringBuffer sb=NewStringBuffer ();  for(inti=0;i<4;i++) {Index=r.nextint (len);//Generate random numbersG.setcolor (NewColor (R.nextint), R.nextint (188), R.nextint (255));//Set Colorg.DrawString (ch[index]+ "", (i*15) +3, 18);//draw numbers and positions of numberssb.append (Ch[index]); } request.getsession (). SetAttribute ("Piccode", sb.tostring ());//keep numbers in session for later useImageio.write (BI, "JPG", Response.getoutputstream ());//Output Picture    }}
Xml
Do not forget to register the new servlet statically
<?XML version= "1.0" encoding= "UTF-8"?><Web-appXmlns:xsi= "Http://www.w3.org/2001/XMLSchema-instance"xmlns= "Http://java.sun.com/xml/ns/javaee"xsi:schemalocation= "Http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"ID= "webapp_id"version= "3.0">  <Display-name>Servlet_sql_mvc_cookie</Display-name>  <welcome-file-list>    <Welcome-file>index.jsp</Welcome-file>  </welcome-file-list>    <servlet>      <Servlet-name>Servletsqlmvccookie</Servlet-name>      <Servlet-class>Com.javaweb.action.ServletSqlMvcCookie</Servlet-class>  </servlet>  <servlet-mapping>      <Servlet-name>Servletsqlmvccookie</Servlet-name>      <Url-pattern>*.do</Url-pattern>  </servlet-mapping>  <servlet>        <Servlet-name>Imageservlet</Servlet-name>        <Servlet-class>Com.javaweb.action.ImageServlet</Servlet-class></servlet><servlet-mapping>        <Servlet-name>Imageservlet</Servlet-name>        <Url-pattern>/imageservlet</Url-pattern></servlet-mapping></Web-app>
Finally, just change the login method
 Public voidLogin (httpservletrequest req, HttpServletResponse resp)throwsservletexception, ioexception {User User=NewUser (); String username=req.getparameter ("username");        User.setusername (username); String Password=req.getparameter ("Password");                User.setpassword (password); String Piccode= (String) req.getsession (). getattribute ("Piccode"); String Checkcode=req.getparameter ("Checkcode");//Take value//checkcode=checkcode.touppercase (); //converts all characters to uppercase (this statement can be used to verify that the code is case-insensitive)Resp.setcontenttype ("TEXT/HTML;CHARSET=GBK");//Solve garbled problems                if(Checkcode.equals (Piccode)) {User use=userservive.login (user); if(use!=NULL) {String [] ischeck=req.getparametervalues ("Ischeck"); if(ischeck!=NULL&& "true". Equals (ischeck[0])){                    //Add cookie InformationCookie usernamecookie=NewCookie ("username"), username); Cookie Passwordcookie=NewCookie ("password"), password); Usernamecookie.setmaxage (60*60*24*1);//DayPasswordcookie.setmaxage (60*60*24*1);                    Resp.addcookie (Usernamecookie);                Resp.addcookie (Passwordcookie); } resp.sendredirect ("Loginsuccess.jsp"); }Else{resp.sendredirect ("Loginfail.jsp"); }        }Else{resp.sendredirect ("Loginfail.jsp"); }    }
The verification code is wrong.
Jsp-5 Generate verification code and verify