Java production image Verification Code

[Java] import javax. servlet. servletException; import javax. servlet. servletOutputStream; import javax. servlet. http. httpServlet; import javax. servlet. http. httpServletRequest; import javax. servlet. http. httpServletResponse; import javax. servlet. http. httpSession; import org. apache. log4j. logger; import com. ailk. bboss. constants. constants; import com. ailk. bboss. util. imageCode; import com.sun.image.codec.jp Eg. export codec; import com.sun.image.codec.jpeg. JPEGImageEncoder;/*** generate random Verification Code */www.2cto. compublic class ValidateCodeServlet extends HttpServlet {private static final long serialVersionUID =-protected; protected void service (HttpServletRequest req, HttpServletResponse response) throws ServletException, java. io. IOException {HttpSession session = req. getSession (); ImageCode image = ne W ImageCode (); // Save the four-digit verification code to the Session. // Disable image caching. Response. setHeader ("Pragma", "no-cache"); response. setHeader ("Cache-Control", "no-cache"); response. setDateHeader ("Expires", 0); response. setContentType ("image/jpeg"); // output the image to the Servlet output stream. ServletOutputStream outStream = response. getOutputStream (); required imageencoder encoder = required codec. createJPEGEncoder (outStream); encoder. encode (image. creatImage (); outStream. close (); session. setAttribute (Constants. VALIDATE_CODE, image. getStrRand (); Logger. getLogger (this. getClass ()). info ("image code =" + image. getStrRand () + "cc") ;}} [java] <pre name = "code" class = "java"> import java. awt. color; import java. awt. font; import java. awt. graphics; import java. awt. geom. affineTransform; import java. awt. image. bufferedImage; import java. util. random; public class ImageCode {private String strRand = ""; public final Color [] defCols = {Color. WHITE, Color. BLACK}; private static String [] CHARS = getChars (); public final Font [] defFonts = {new Font ("", Font. BOLD, 18), new Font ("", Font. BOLD, 18), new Font ("", Font. BOLD, 18), new Font ("", Font. BOLD, 18), new Font ("rom7", Font. BOLD, 18)}; private Font getFont (int I) {Random random = new Random (new Double (Math. random () * 10000 * (I + 1 )). longValue (); int a = random. nextInt (defFonts. length); AffineTransform trans = new AffineTransform (); trans. scale (1 + random. nextFloat () * 0.2, 0.95 + random. nextFloat () * 0.65); return defFonts [a]. deriveFont (trans);} public BufferedImage creatImage () {int width = 75, height = 20; BufferedImage image = new BufferedImage (width, height, BufferedImage. TYPE_INT_RGB); Graphics g = image. getGraphics (); Random random = new Random (); g. setColor (new Color (202,255,255); g. fillRect (0, 0, width, height); String arr [] = CHARS; Random rm = new Random (new Double (Math. random () * 10000*59 ). longValue (); g. setColor (Color. BLACK); for (int I = 0; I <4; I ++) {String rand = arr [rm. nextInt (arr. length)]; strRand + = rand; g. setFont (getFont (I); if (I = 0) g. drawString (rand, 2 + random. nextInt (2), 20); else g. drawString (rand, 16 * I + 2 + random. nextInt (3), 20);} g. dispose (); return image;} public String getStrRand () {return strRand;} public void setStrRand (String strRand) {this. strRand = strRand;} www.2cto.com private static String [] getChars () {String [] chars = null; chars = new String [] {"2", "3 ", "4", "5", "6", "7", "8", "9", "A", "B", "D", "E ", "F", "G", "H", "J", "K", "L", "M", "N", "P", "R ", "S", "U", "V", "X", "Y", "Z"}; return chars ;}} </pre> <br> <pre> </pre>