Java Implementation Verification Code function

 PackageCom.verification_code.servlet;ImportJava.awt.Color;ImportJava.awt.Font;ImportJava.awt.Graphics;ImportJava.awt.image.BufferedImage;Importjava.io.IOException;ImportJava.io.OutputStream;ImportJava.util.Random;ImportJavax.imageio.ImageIO;Importjavax.servlet.ServletException;ImportJavax.servlet.http.HttpServlet;Importjavax.servlet.http.HttpServletRequest;ImportJavax.servlet.http.HttpServletResponse; Public classImgservletextendshttpservlet{@Overrideprotected voiddoget (httpservletrequest req, HttpServletResponse resp)throwsservletexception, IOException {//TODO auto-generated Method StubDoPost (REQ,RESP); } @Overrideprotected voidDoPost (httpservletrequest req, HttpServletResponse resp)throwsservletexception, IOException {//TODO auto-generated Method Stub//set the response startResp.setcontenttype ("Image/jpeg"); //Settings page does not cacheResp.setheader ("Pragma", "No-cache"); Resp.setheader ("Cache-control", "No-cache"); Resp.setdateheader ("Expires", 0); OutputStream out=Resp.getoutputstream (); //Set the width height of the picture        intWidth=88,height=20; BufferedImage Image=NewBufferedImage (WIDTH,HEIGHT,BUFFEREDIMAGE.TYPE_INT_RGB); Graphics g=Image.getgraphics (); //Generating Random classesRandom random =NewRandom ();        G.setcolor (Color.White); G.fillrect (0, 0, width, height); //Set FontG.setfont (NewFont ("Times New Roman", font.bold+font.italic,18)); //Draw BorderG.setcolor (Getrandcolor (0, 20));//---2G.drawrect (0, 0, width-1, height-1); //randomly generated interference lines        intCount = 100; intLineWidth = 3;//width of the interference line         for(inti = 0; I < count; i++) {G.setcolor (Getrandcolor (150, 200));//---3            intx = Random.nextint (width-linewidth-1) + 1;//guaranteed to draw within the frame            inty = Random.nextint (height-linewidth-1) + 1; intXL =Random.nextint (linewidth); intYL =Random.nextint (linewidth); G.drawline (x, y, x+ XL, Y +yl); }        //generate random Verification codeString srand= ""; String str[]={"0", "1", "2", "3", "4", "5", "6", "7", "8", "9",                "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"};  for(inti=0;i<4;i++){            intRand = Random.nextint (36); SRand+=Str[rand]; //Set Random ColorsG.setcolor (NewColor (20+random.nextint, 20+random.nextint), 20+random.nextint (110))); //Drawingg.DrawString (Str[rand], 20*i+8, 16); } req.getsession (). SetAttribute ("Verification_code", SRand);        G.dispose (); Imageio.write (Image,"JPEG", out); }     PublicColor Getrandcolor (intFcintBC) {//get random color for a given rangeRandom 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); }}

Page

<script type= "text/javascript" >    function Refresh () {        document.getElementById ("Id_code" ). src= "Image?" +math.random ();         // loginform.code.src= "image?" +math.random ();    }
</script>

Java Implementation Verification Code function