jcaptcha 验证码程序

package com.yh.web.jcaptcha; import java.awt.Color; import java.awt.Font; import java.awt.image.BufferedImage; import java.io.IOException; import java.io.OutputStream; import java.util.ArrayList; import java.util.Iterator; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.apache.log4j.Logger; import com.octo.captcha.component.image.backgroundgenerator.BackgroundGenerator; import com.octo.captcha.component.image.backgroundgenerator.GradientBackgroundGenerator; import com.octo.captcha.component.image.fontgenerator.FontGenerator; import com.octo.captcha.component.image.fontgenerator.RandomFontGenerator; import com.octo.captcha.component.image.textpaster.RandomTextPaster; import com.octo.captcha.component.image.textpaster.SimpleTextPaster; import com.octo.captcha.component.image.textpaster.TextPaster; import com.octo.captcha.component.image.wordtoimage.ComposedWordToImage; import com.octo.captcha.component.image.wordtoimage.WordToImage; import com.octo.captcha.component.word.wordgenerator.RandomWordGenerator; import com.octo.captcha.component.word.wordgenerator.WordGenerator; import com.octo.captcha.engine.image.ListImageCaptchaEngine; import com.octo.captcha.image.ImageCaptcha; import com.octo.captcha.image.ImageCaptchaFactory; import com.octo.captcha.image.gimpy.GimpyFactory; import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGImageEncoder; public class CaptchaServiceSingleton extends ListImageCaptchaEngine { private static Logger log = Logger.getLogger(CaptchaServiceSingleton.class); private static final Integer MIN_WORD_LENGTH = new Integer(4); private static final Integer MAX_WORD_LENGTH = new Integer(5); private static final Integer IMAGE_WIDTH = new Integer(90); private static final Integer IMAGE_HEIGHT = new Integer(30); private static final Integer MIN_FONT_SIZE = new Integer(12); private static final Integer MAX_FONT_SIZE = new Integer(14); private static final String NUMERIC_CHARS = "23456789";// No numeric 0 private static final String UPPER_ASCII_CHARS = "工要在地一上是中国同民我人有的和主产不ABCDEFGHJKLMNPQRSTXYZ";// No // upper // O I // we dont use the lower characters because it cause dificult in some case, // so that // we must always UPPERCASE the input from user (currently in // OnlineUserImpl) private static final String LOWER_ASCII_CHARS = "abcdefghjkmnpqrstxyz";// No // lower // o i /** * Singleton instance of this class */ private static CaptchaServiceSingleton instance = new CaptchaServiceSingleton(); private ArrayList textPasterList; private ArrayList backgroundGeneratorList; private ArrayList fontGeneratorList; ImageCaptcha imageCaptcha = null; /** * Private constructor to prevent instantiation */ private CaptchaServiceSingleton() { } public static CaptchaServiceSingleton getInstance() { return instance; } protected void buildInitialFactories() { try { textPasterList = new ArrayList(); backgroundGeneratorList = new ArrayList(); fontGeneratorList = new ArrayList(); textPasterList.add(new SimpleTextPaster(MIN_WORD_LENGTH, MAX_WORD_LENGTH, Color.black)); textPasterList.add(new RandomTextPaster(MIN_WORD_LENGTH, MAX_WORD_LENGTH, Color.black)); textPasterList.add(new SimpleTextPaster(MIN_WORD_LENGTH, MAX_WORD_LENGTH, Color.black)); textPasterList.add(new RandomTextPaster(MIN_WORD_LENGTH, MAX_WORD_LENGTH, Color.black)); textPasterList.add(new SimpleTextPaster(MIN_WORD_LENGTH, MAX_WORD_LENGTH, Color.blue)); textPasterList.add(new RandomTextPaster(MIN_WORD_LENGTH, MAX_WORD_LENGTH, Color.blue)); backgroundGeneratorList.add(new GradientBackgroundGenerator( IMAGE_WIDTH, IMAGE_HEIGHT, Color.orange, Color.white)); backgroundGeneratorList.add(new GradientBackgroundGenerator( IMAGE_WIDTH, IMAGE_HEIGHT, Color.white, Color.green)); backgroundGeneratorList.add(new GradientBackgroundGenerator( IMAGE_WIDTH, IMAGE_HEIGHT, Color.gray, Color.white)); backgroundGeneratorList.add(new GradientBackgroundGenerator( IMAGE_WIDTH, IMAGE_HEIGHT, Color.white, Color.orange)); backgroundGeneratorList.add(new GradientBackgroundGenerator( IMAGE_WIDTH, IMAGE_HEIGHT, Color.green, Color.white)); backgroundGeneratorList.add(new GradientBackgroundGenerator( IMAGE_WIDTH, IMAGE_HEIGHT, Color.yellow, Color.white)); backgroundGeneratorList.add(new GradientBackgroundGenerator( IMAGE_WIDTH, IMAGE_HEIGHT, Color.white, Color.magenta)); // fontGeneratorList.add(new // TwistedAndShearedRandomFontGenerator(MIN_FONT_SIZE, // MAX_FONT_SIZE)); // fontGeneratorList.add(new // TwistedRandomFontGenerator(MIN_FONT_SIZE, MAX_FONT_SIZE));// link // character too much Font f = Font.decode("华文细黑"); fontGeneratorList.add(new RandomFontGenerator(MIN_FONT_SIZE, MAX_FONT_SIZE,new Font[]{f}));// to easy to read // fontGeneratorList.add(new // DeformedRandomFontGenerator(MIN_FONT_SIZE, MAX_FONT_SIZE));// to // small font // no char upper O, char lower o and numerric 0 because user cannot // answer WordGenerator words = new RandomWordGenerator(NUMERIC_CHARS + UPPER_ASCII_CHARS); for (Iterator fontIter = fontGeneratorList.iterator(); fontIter .hasNext();) { FontGenerator font = (FontGenerator) fontIter.next(); for (Iterator backIter = backgroundGeneratorList.iterator(); backIter .hasNext();) { BackgroundGenerator back = (BackgroundGenerator) backIter .next(); for (Iterator textIter = textPasterList.iterator(); textIter .hasNext();) { TextPaster parser = (TextPaster) textIter.next(); WordToImage word2image = new ComposedWordToImage(font, back, parser); ImageCaptchaFactory factory = new GimpyFactory(words, word2image); addFactory(factory); } } } } catch (Exception ex) { log.error("产生校验码初始化异常 ＝＝ " + ex); // throw ex; } } /** * Write the captcha image of current user to the servlet response * * @param request * HttpServletRequest * @param response * HttpServletResponse * @throws IOException */ public void writeCaptchaImage(HttpServletRequest request, HttpServletResponse response) throws IOException { imageCaptcha = getNextImageCaptcha(); HttpSession session = request.getSession(); session.setAttribute("imageCaptcha", imageCaptcha); BufferedImage image = (BufferedImage) imageCaptcha.getChallenge(); OutputStream outputStream = null; try { outputStream = response.getOutputStream(); // render the captcha challenge as a JPEG image in the response response.setHeader("Cache-Control", "no-store"); response.setHeader("Pragma", "no-cache"); response.setDateHeader("Expires", 0); response.setContentType("image/jpeg"); JPEGImageEncoder encoder = JPEGCodec .createJPEGEncoder(outputStream); encoder.encode(image); outputStream.flush(); outputStream.close(); outputStream = null;// no close twice } catch (IOException ex) { log.error("产生图片异常 ＝＝ " + ex); throw ex; } finally { if (outputStream != null) { try {