Generate Random Captcha Tool class

Generate Random Verification code

 PackageCom.web;//Validation code Generation processing classImportJava.awt.BasicStroke;ImportJava.awt.Color;ImportJava.awt.Font;ImportJava.awt.Graphics;ImportJava.awt.Graphics2D;ImportJava.awt.geom.AffineTransform;ImportJava.awt.geom.Line2D;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;Importjavax.servlet.http.HttpSession;Importcom.tools.MD5; Public classPicturecheckcodeextendshttpservlet{Private Static Final LongSerialversionuid = 1L; PrivateRandom rand=NewRandom (); /*** Generate random colors * *@paramstart [int] *@paramend [INT] *@returnColor [Object]*/     PublicColor Getrandcolor (intStartintend) {        intRandnum; if(start>255) start=255; if(end>255) end=255; if(start>end) randnum=start-end; Elserandnum=end-start; intr=start+Rand.nextint (Randnum); intg=start+Rand.nextint (Randnum); intb=start+Rand.nextint (Randnum); return NewColor (R,G,B); }            /*** coloring \ Rotation \ Zoom * *@paramWord text *@paramg Picture Object*/     Public voidColoredandrotation (String Word,intI,graphics g) {        /**Coloring **/G.setcolor (NewColor (20+rand.nextint, 20+rand.nextint), 20+rand.nextint (110))); /**Rotation **/graphics2d g2d=(graphics2d) G; AffineTransform Trans=NewAffineTransform (); Trans.rotate (Rand.nextint (*3.14/180,15*i+8,7)); /**Zoom **/        floatScalesize=rand.nextfloat () +0.8f; if(scalesize>1f) scalesize=1f;        Trans.scale (Scalesize, scalesize);        G2d.settransform (trans); g.DrawString (Word,15*i+20,20); }        /*** Generate 100 lines of interference * *@paramG2d *@paramWidth *@paramHeight*/     Public voidGetrandline (Graphics2D g2d,intWidthintheight) {         for(inti=0;i<100;i++){            intX=rand.nextint (width-1); intY=rand.nextint (height-1); intZ=rand.nextint (6) +1; intW=rand.nextint (12) +1; Basicstroke BS=NewBasicstroke (2f,basicstroke.cap_butt,basicstroke.join_bevel); Line2D Line=NewLine2d.double (x,y,x+z,y+W);            G2d.setstroke (BS);        G2d.draw (line); }    }        /*** Get Random text * *@paramlength [int] captcha size *@paramg [Graphics] Picture Object *@returnString * @case1: A-Z * @case2: Chinese * @default: 0-9*/@SuppressWarnings ("Unused")     PublicString Getrandword (intLength,graphics g) {String Finalword= "", firstword= ""; intTempint=0; String[] Array={                "0", "1", "2", "3",                "4", "5", "6", "7",                "8", "9", "a", "B",                "C", "D", "E", "F"};  for(inti=0;i<length;i++){            Switch(Rand.nextint (2)){                 Case1: Tempint=rand.nextint (26) +65; FirstWord=string.valueof ((Char) tempint);  Break; /*Case 2:int R1,R2,R3,R4; String Strh,strl;//high&low R1=rand.nextint (3) +11;                        Front closed rear open [11,14] if (r1==13) {r2=rand.nextint (7);                        }else{R2=rand.nextint (16);                        } r3=rand.nextint (6) +10;                        if (r3==10) {r4=rand.nextint (15) +1;                        }else if (r3==15) {r4=rand.nextint (15);                        }else{R4=rand.nextint (16);                        } STRH=ARRAY[R1]+ARRAY[R2];                                                STRL=ARRAY[R3]+ARRAY[R4];                        Byte[] Bytes=new byte[2];                        Bytes[0]= (Byte) (Integer.parseint (strh,16)); Bytes[1]= (Byte) (InteGer.parseint (strl,16));                        Firstword=new String (bytes); Break*/                default: Tempint=rand.nextint (10) +48; FirstWord=string.valueof ((Char) tempint);  Break; } Finalword+=FirstWord;  This. Coloredandrotation (Firstword,i, G); }                returnFinalword; }    protected voidService (HttpServletRequest request, httpservletresponse response)throwsservletexception, IOException {//setting does not cache picturesResponse.setheader ("Pragma", "No-cache"); Response.setheader ("Cache-control", "No-cache"); Response.setdateheader ("Expires", 0); //Create a pictureResponse.setcontenttype ("Image/jpeg"); intwidth=100; intHeight=40; BufferedImage Image=NewBufferedImage (WIDTH,HEIGHT,BUFFEREDIMAGE.TYPE_INT_RGB); Graphics g=Image.getgraphics (); Graphics2D g2d=(graphics2d) G; Font Mfont=NewFont ("Arial", font.bold,22); G.setcolor ( This. Getrandcolor (200,250)); G.fillrect (0, 0, width, height);        G.setfont (Mfont); G.setcolor ( This. Getrandcolor (180,200));  This. Getrandline (g2d, width, height); String Randcode= This. Getrandword (4, G); HttpSession Session=request.getsession (); Session.setattribute ("Randcode", Md5.code (Randcode.tolowercase ()));                G.dispose (); Imageio.write (Image,"JPEG", Response.getoutputstream ()); }}

Generate Random Captcha Tool class