Java Graphics Verification Code

JSP that generated the verification code:

1<%@ page contenttype= "image/jpeg" language= "Java"Import= "java.util.*,java.awt.*,java.awt.image.*,javax.imageio.*" pageencoding= "Utf-8"%>2 3<%!4Color Getrandcolor (intFcintBC) {5Random random =NewRandom ();6     if(FC > 255){7FC = 255;8     }9     if(BC < 255){TenBC = 255; One     } A     intr = FC +random.nextint (bc-FC); -     intg = FC +random.nextint (bc-FC); -     intb = FC +random.nextint (bc-FC); the  -  -     return NewColor (r,g,b); -   } +%> -  +<% A   //Settings page does not cache atResponse.setheader ("Pragma", "No-cache"); -Response.setheader ("Cache-control", "No-catch"); -Response.setdateheader ("Expires", 0); -  -   //Create an image in memory -   intwidth = 60; in   intHeight = 42; -BufferedImage image =NewBufferedImage (WIDTH,HEIGHT,BUFFEREDIMAGE.TYPE_INT_RGB); to  +   //Creating Images -Graphics g =image.getgraphics (); the   //Generating Random objects *Random random =NewRandom (); $   //Set Background colorPanax NotoginsengG.setcolor (Getrandcolor (200,250)); -G.fillrect (0,0, width,height); the   //Set Font +G.setfont (NewFont ("Tines Nev Roman", font.plain,24)); A   //randomly generated interference lines the +G.setcolor (Getrandcolor (160,200)); -    for(inti = 0; I < 255; i++){ $     intx =random.nextint (width); $     inty =random.nextint (height); -     intXL = Random.nextint (12); -     intYL = Random.nextint (12); theG.drawline (x, Y, X+XL, y+yl); -   }WuyiG.setcolor (Getrandcolor (65,105)); the    for(inti = 0; I < 4; i++){ -     intx =random.nextint (width); Wu     inty =random.nextint (height); -     intXL = Random.nextint (12); About     intYL = Random.nextint (12); $G.drawline (x, Y, X+XL, y+yl); -   } -  -   //randomly generated authentication code, 4 digits AString SRand = ""; +    for(inti = 0; I < 4; i++){ theString rand = string.valueof (Random.nextint (10)); -SRand + =Rand; $     //Display the authentication code to the image theG.setcolor (NewColor (+ random.nextint, + random.nextint), + random.nextint (110))); theg.DrawString (Rand,13*i+6,25+random.nextint (10)); the   } theSession.setattribute ("RCode", SRand); -   //Image Effective in g.dispose (); the   //output image to page theImageio.write (Image, "JPEG", Response.getoutputstream ()); About out.clear (); theout =pagecontext.pushbody (); the%>

Front Reference:

<id= "Cknumber"  src= "Loginaction!getnumber.iol"/>  <type= "text"  name= "Code"  class  = "Ta_login_inputneed_notice"/>

Click on the image to refresh the verification code:

Principle: Use jquery to modify the SRC attribute of img, Note: src should be different from before .

Method: Randomly generate a parameter after the link so that the link is not the same as before, I am here by time to generate.

                <script>                    $ (document). Ready (function  () {                        $ ("#ckNumber"). Click (  function  () {                            varnew Date (). GetTime () + ' a ' + math.random ();                            $ (this). attr (' src ', $ (this). attr (' src ') + append)                    })                 </script>

Background verification (for reference only):

if (!request.getparameter ("code"). Equals ( this

Java Graphics Verification Code