"Spring" based on SPRINGMVC's image verification code function implementation

Background implementation code:

Imgcontroller.java file

 PackageCn.shop.controller;ImportJava.awt.Color;ImportJava.awt.Font;ImportJava.awt.Graphics;ImportJava.awt.image.BufferedImage;Importjava.io.IOException;ImportJava.util.HashMap;ImportJava.util.Map;ImportJava.util.Random;ImportJavax.imageio.ImageIO;Importjavax.servlet.http.HttpServletRequest;ImportJavax.servlet.http.HttpServletResponse;Importjavax.servlet.http.HttpSession;ImportOrg.springframework.stereotype.Controller;Importorg.springframework.web.bind.annotation.RequestMapping;ImportOrg.springframework.web.bind.annotation.ResponseBody;ImportCom.google.gson.Gson; @Controller Public classImgcontroller {@RequestMapping ({"Authcode.htgo"})     Public voidGetauthcode (httpservletrequest request, HttpServletResponse response,httpsession session)throwsIOException {intwidth = 63; intHeight = 37; Random Random=NewRandom (); //Set Response header information//Disable CachingResponse.setheader ("Pragma", "No-cache"); Response.setheader ("Cache-control", "No-cache"); Response.setdateheader ("Expires", 0); //Generate buffer Image classBufferedImage image =NewBufferedImage (width, height, 1); //the graphics that produce the image class are used for drawing operationsGraphics g =Image.getgraphics (); //style of the graphics classG.setcolor ( This. Getrandcolor (200, 250)); G.setfont (NewFont ("Times New Roman", 0,28)); G.fillrect (0, 0, width, height); //Draw Interference Lines         for(inti=0;i<40;i++) {G.setcolor ( This. Getrandcolor (130, 200)); intx =random.nextint (width); inty =random.nextint (height); intX1 = Random.nextint (12); intY1 = Random.nextint (12); G.drawline (x, y, x+ x1, y +y1); }        //Drawing charactersString Strcode = "";  for(inti=0;i<4;i++) {String rand= String.valueof (Random.nextint (10)); Strcode= Strcode +Rand; G.setcolor (NewColor (20+random.nextint, 20+random.nextint), 20+random.nextint (110))); g.DrawString (Rand,13*i+6, 28); }        //saving characters to the session for verification of the front endSession.setattribute ("Strcode", Strcode);        G.dispose (); Imageio.write (Image,"JPEG", Response.getoutputstream ());    Response.getoutputstream (). Flush (); }        //Create colorColor Getrandcolor (intFcintBC) {Random random=NewRandom (); if(fc>255) FC= 255; if(bc>255) BC= 255; intr = FC + random.nextint (BC-FC); intg = FC + random.nextint (BC-FC); intB = fc + random.nextint (BC-FC); return NewColor (R,G,B); }    /*** Verify that the user's verification code is correct *@paramvalue user-entered verification code *@paramRequest HttpServletRequest Object *@returna string of type strings. The format is:<br/> * {"res",boolean},<br/> * If {"res", true}, indicating successful validation <br/&     Gt * If {"res", false} indicates that the validation failed*/@RequestMapping ("Validate.htgo") @ResponseBody Publicstring Validate (string Value,httpservletrequest request) {string Valuecode= (String) request.getsession (). getattribute ("Strcode"); Map Map=NewHashMap (); if(valuecode!=NULL){            if(Valuecode.equals (value)) {Map.put ("Res",true); return NewGson (). ToJson (map); }} map.put ("Res",false); return NewGson (). ToJson (map); }}

Imgcontroller.java

Front-End Part code:

    <Divclass= "Form-group">Verification Code:<inputID= "Authcode"name= "Authcode"type= "text"/>        <!--here the value of the SRC attribute of the IMG tag is the request address of the background implementation picture Captcha method -        <label><imgtype= "image"src= "Authcode.do"ID= "Codeimage"onclick= "Chagecode ()"title= "The picture is not clear?" Click to re-get verification Code "style= "Cursor:pointer;"/></label>        <label><aonclick= "Chagecode ()">Another one.</a></label>    </Div>

To achieve the click image Update JS Method:

    function Chagecode () {        $ (' #codeImage '). attr (' src ', ' authcode.do?abc= ' +math.random ());   Add math.random after linking to ensure that a new verification code is generated each time to avoid caching problems.     }

When the form is submitted, it can be verified by Ajax and the user's input is correct:

$.post (  "validate.do",  {"value": $ ("#code_input"). Val ()},  function  (res) {      if(res.res) {          alert ("validation succeeded");       } Else {          alert ("validation failed");
Refresh Verification Code Picture
$ ("#codeImage"). Trigger ("click");       }  },  "JSON");

"Spring" based on SPRINGMVC's image verification code function implementation