@Action("/validimg")

public String validimg() throws Exception {

        genernateCaptchaImage();

        return null;

}

protected void genernateCaptchaImage() throws IOException {

        response.setHeader("Cache-Control", "no-store");

        response.setHeader("Pragma", "no-cache");

        response.setDateHeader("Expires", 0);

        response.setContentType("image/jpeg");

        ServletOutputStream out = response.getOutputStream();

        try {

            String captchaId = request.getSession(true).getId();

            LOGGER.info("当前生产验证码的sessionId为: "+captchaId);

            BufferedImage challenge = (BufferedImage) CaptchaServiceSingleton.getInstance().getChallengeForID(

                    captchaId, request.getLocale());

            ImageIO.write(challenge, "jpg", out);

            out.flush();

        } catch (CaptchaServiceException e) {

        } finally {

            out.close();

        }

    }

/**

 * JCaptcha的单例

 *

 * @author fuxingxign

 */

public class CaptchaServiceSingleton {

    private static ImageCaptchaService instance = new DefaultManageableImageCaptchaService(

            new FastHashMapCaptchaStore(), new RdImageEngine(), 180, 100000, 75000);

    /*

     * private static ImageCaptchaService instance = new DefaultManageableImageCaptchaService( new

     * FastHashMapCaptchaStore(), new GMailEngine(), 180, 100000 , 75000);

     */

    public static ImageCaptchaService getInstance() {

        return instance;

    }

}

import java.awt.Color;

import java.awt.Font;

import com.octo.captcha.component.image.backgroundgenerator.BackgroundGenerator;

import com.octo.captcha.component.image.backgroundgenerator.UniColorBackgroundGenerator;

import com.octo.captcha.component.image.color.RandomRangeColorGenerator;

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.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.gimpy.GimpyFactory;

public class RdImageEngine extends ListImageCaptchaEngine {

    @Override

    protected void buildInitialFactories() {

        WordGenerator wgen = new RandomWordGenerator("abcdefghijklmnopqrstuvwxyz");

        RandomRangeColorGenerator cgen = new RandomRangeColorGenerator(new int[] { 0, 100 }, new int[] { 0, 100 },

                new int[] { 0, 100 });

        TextPaster textPaster = new RandomTextPaster(Integer.valueOf(4),Integer.valueOf(4), cgen, true);

        BackgroundGenerator backgroundGenerator = new UniColorBackgroundGenerator(Integer.valueOf(80), Integer.valueOf(37),

                Color.WHITE);

        Font[] fontsList = new Font[] { new Font("Arial", 0, 12), new Font("Tahoma", 0, 12),

                new Font("Verdana", 0, 12), };

        FontGenerator fontGenerator = new RandomFontGenerator(Integer.valueOf(26),Integer.valueOf(26), fontsList);

        WordToImage wordToImage = new ComposedWordToImage(fontGenerator, backgroundGenerator, textPaster);

        this.addFactory(new GimpyFactory(wgen, wordToImage));

    }

}