Online book Store Project study notes-006 CAPTCHA function

I. Methods of Use

In 1.jsp

1       <tr>2         <td>&nbsp;</td>3         <td>4           class = "Verifycodeimg" ></span >5         </td>6         <td><a href= "javascript: _changeverifycode ()" > Change </a></td>7       </tr>8       <tr>

Configuring Servlets in 2.web.xml

1   <!--generate verification code-2   <servlet>3       <servlet-name>verifycodeservlet</ Servlet-name>4       <servlet-class>cn.itcast.vcode.servlet.verifycodeservlet</ servlet-class>5   </servlet>6   <servlet-mapping>7        <servlet-name>VerifyCodeServlet</servlet-name>8       <url-pattern>/ Verifycodeservlet</url-pattern>9   </servlet-mapping>

Second, code codes

1.verifycodeservlet.java

1  PackageCn.itcast.vcode.servlet;2 3 ImportJava.awt.image.BufferedImage;4 Importjava.io.IOException;5 6 Importjavax.servlet.ServletException;7 ImportJavax.servlet.http.HttpServlet;8 Importjavax.servlet.http.HttpServletRequest;9 ImportJavax.servlet.http.HttpServletResponse;Ten  One ImportCn.itcast.vcode.utils.VerifyCode; A  -@SuppressWarnings ("Serial") -  Public classVerifycodeservletextendsHttpServlet { the      Public voiddoget (httpservletrequest request, httpservletresponse response) -             throwsservletexception, IOException { -Verifycode VC =NewVerifycode (); -BufferedImage image = Vc.getimage ();//Get a one-time verification code picture +         //The method must be called after the GetImage () method. - //System.out.println (Vc.gettext ());//get text on a picture +Verifycode.output (image, Response.getoutputstream ());//write the picture into the specified stream A          at         //Save the text in session to prepare for Loginservlet validation -Request.getsession (). SetAttribute ("Vcode", Vc.gettext ()); -     } -}

2.verifycode.java

1  Packagecn.itcast.vcode.utils;2 3 ImportJava.awt.BasicStroke;4 ImportJava.awt.Color;5 ImportJava.awt.Font;6 ImportJava.awt.Graphics2D;7 ImportJava.awt.image.BufferedImage;8 Importjava.io.IOException;9 ImportJava.io.OutputStream;Ten ImportJava.util.Random; One  A ImportJavax.imageio.ImageIO; -  -  Public classVerifycode { the     Private intW = 70; -     Private intH = 35; -      PrivateRandom r =NewRandom (); -      //{"Arial", "Chinese Italic", "Black Body", "Chinese New Wei", "Chinese Script", "Microsoft Ya Hei", "italics _gb2312"} +     PrivateString[] FontNames = {"Arial", "Chinese Italic", "Black Body", "Microsoft Jas", "italics _gb2312"}; -     PrivateString codes = "23456789abcdefghjkmnopqrstuvwxyzABCDEFGHJKMNPQRSTUVWXYZ"; +     PrivateColor BgColor =NewColor (255, 255, 255); A     PrivateString text; at      -     PrivateColor Randomcolor () { -         intRed = R.nextint (150); -         intGreen = R.nextint (150); -         intBlue = R.nextint (150); -         return NewColor (red, green, blue); in     } -      to     PrivateFont Randomfont () { +         intindex =R.nextint (fontnames.length); -String FontName =Fontnames[index]; the         intstyle = R.nextint (4); *         intSize = R.nextint (5) + 24;  $         return NewFont (fontname, style, size);Panax Notoginseng     } -      the     Private voidDrawLine (bufferedimage image) { +         intnum = 3; Agraphics2d g2 =(graphics2d) image.getgraphics (); the          for(inti = 0; i < num; i++) { +             intX1 =R.nextint (w); -             intY1 =r.nextint (h); $             intx2 =R.nextint (w); $             inty2 =r.nextint (h); -G2.setstroke (NewBasicstroke (1.5F));  - G2.setcolor (color.blue); the g2.drawline (x1, y1, x2, y2); -         }Wuyi     } the      -     Private CharRandomchar () { Wu         intindex =R.nextint (Codes.length ()); -         returnCodes.charat (index); About     } $      -     Privatebufferedimage createimage () { -BufferedImage image =NewBufferedImage (W, H, Bufferedimage.type_int_rgb); -graphics2d g2 =(graphics2d) image.getgraphics (); AG2.setcolor ( This. BgColor); +G2.fillrect (0, 0, W, h); the          returnimage; -     } $      the      Publicbufferedimage getImage () { theBufferedImage image =createimage (); thegraphics2d g2 =(graphics2d) image.getgraphics (); theStringBuilder SB =NewStringBuilder (); -         //Draw 4 characters into a picture in          for(inti = 0; I < 4; i++)  { theString s = Randomchar () + "";  the Sb.append (s); About             floatx = i * 1.0F * W/4;  the G2.setfont (Randomfont ()); the G2.setcolor (Randomcolor ()); theG2.drawstring (S, x, h-5);  +         } -          This. Text =sb.tostring (); the drawLine (image);Bayi         returnimage;  the     } the      -      PublicString GetText () { -         returntext; the     } the      the      Public Static voidoutput (bufferedimage image, outputstream out) the                 throwsIOException { -Imageio.write (Image, "JPEG", out); the     } the}

Web Book Mall Project study notes-006 CAPTCHA function