使用JCaptcha組件生成驗證碼
以下為項目中所用代碼，文筆有限，直接上代碼。
所需jar包：
是否需要其他依賴包，不詳
web.xml
<servlet>
<servlet-name>Jcaptcha</servlet-name>
<servlet-class>com.bkgd.cms.servlet.JcaptchaServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>Jcaptcha</servlet-name>
<url-pattern>/captcha.svl</url-pattern>
</servlet-mapping> 需要一個服務類 生成Image
package com.bkgd.cms.servlet;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.apache.commons.io.output.ByteArrayOutputStream;
import org.apache.log4j.Logger;
import com.octo.captcha.service.CaptchaServiceException;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
@SuppressWarnings("serial")
public class JcaptchaServlet extends HttpServlet {
public static final String CAPTCHA_IMAGE_FORMAT = "jpeg";
private static final Logger log = Logger.getLogger(JcaptchaServlet.class);
@Override
public void init() throws ServletException {
}
/**
* @step1 本方法使用Jcaptcha工具生成img圖片，并輸出到客戶端
* @step2 將來在用戶提交的action中插入下面語句進行驗證碼的校驗：Boolean isResponseCorrect =
* captchaService.validateResponseForID( captchaId, "");
**/
@Override
protected void doGet(HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException {
byte[] captchaChallengeAsJpeg = null;
ByteArrayOutputStream jpegOutputStream = new ByteArrayOutputStream();
try {
// 借助于HttpSession ID存儲Captcha ID，開發者也可以借助于其他惟一值
String captchaId = request.getSession().getId();
// 獲得GMailEngine使用的圖片內容
BufferedImage challenge = JCaptchaServiceSingleton.getInstance().getImageChallengeForID(captchaId, request.getLocale());
// 輸出JPEG格式
JPEGImageEncoder jpegEncoder = JPEGCodec.createJPEGEncoder(jpegOutputStream);
jpegEncoder.encode(challenge);
} catch (IllegalArgumentException e) {
log.error(e);
response.sendError(HttpServletResponse.SC_NOT_FOUND);
return;
} catch (CaptchaServiceException e) {
log.error(e);
response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
return;
}
captchaChallengeAsJpeg = jpegOutputStream.toByteArray();
response.setHeader("Cache-Control", "no-store");
response.setHeader("Pragma", "no-cache");
response.setDateHeader("Expires", 0);
// 輸出JPEG圖片
response.setContentType("image/jpeg");
ServletOutputStream responseOutputStream = response.getOutputStream();
responseOutputStream.write(captchaChallengeAsJpeg);
responseOutputStream.flush();
responseOutputStream.close();
}
} JCaptchaServiceSingleton
package com.bkgd.cms.servlet;
import com.octo.captcha.service.captchastore.FastHashMapCaptchaStore;
import com.octo.captcha.service.image.DefaultManageableImageCaptchaService;
import com.octo.captcha.service.image.ImageCaptchaService;
public class JCaptchaServiceSingleton {
private static ImageCaptchaService imageCaptchaService = new DefaultManageableImageCaptchaService(
new FastHashMapCaptchaStore(), new GMailEngine(), 180, 100000,
75000);
public static ImageCaptchaService getInstance() {
return imageCaptchaService;
}
} 驗證碼樣式的圖片引擎GMailEngine
package com.bkgd.cms.servlet;
import java.awt.Color;
import java.awt.Font;
import java.awt.image.ImageFilter;
import com.octo.captcha.component.image.backgroundgenerator.BackgroundGenerator;
import com.octo.captcha.component.image.backgroundgenerator.UniColorBackgroundGenerator;
import com.octo.captcha.component.image.color.RandomListColorGenerator;
import com.octo.captcha.component.image.deformation.ImageDeformation;
import com.octo.captcha.component.image.deformation.ImageDeformationByFilters;
import com.octo.captcha.component.image.fontgenerator.FontGenerator;
import com.octo.captcha.component.image.fontgenerator.RandomFontGenerator;
import com.octo.captcha.component.image.textpaster.DecoratedRandomTextPaster;
import com.octo.captcha.component.image.textpaster.TextPaster;
import com.octo.captcha.component.image.textpaster.textdecorator.TextDecorator;
import com.octo.captcha.component.image.wordtoimage.DeformedComposedWordToImage;
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;
/**
* 仿照JCaptcha2.0編寫GMail驗證碼樣式的圖片引擎.
*/
public class GMailEngine extends ListImageCaptchaEngine {
@Override
protected void buildInitialFactories() {
int minWordLength = 4;
int maxWordLength = 4;
int fontSize = 26;
int imageWidth = 110;
int imageHeight = 50;
//在頁面上將顯示的內容
WordGenerator dictionnaryWords = new RandomWordGenerator("1234567890");
TextPaster randomPaster = new DecoratedRandomTextPaster(minWordLength,
maxWordLength, new RandomListColorGenerator(
new Color[] { new Color(0, 0, 0) }),
new TextDecorator[] {});
BackgroundGenerator background = new UniColorBackgroundGenerator(
imageWidth, imageHeight, Color.white);
FontGenerator font = new RandomFontGenerator(fontSize, fontSize,
new Font[] { new Font("nyala", Font.BOLD, fontSize),
new Font("Bell MT", Font.PLAIN, fontSize),
new Font("Credit valley", Font.BOLD, fontSize) });
ImageDeformation postDef = new ImageDeformationByFilters(new ImageFilter[] {});
ImageDeformation backDef = new ImageDeformationByFilters(new ImageFilter[] {});
ImageDeformation textDef = new ImageDeformationByFilters(new ImageFilter[] {});
WordToImage word2image = new DeformedComposedWordToImage(font,
background, randomPaster, backDef, textDef, postDef);
addFactory(new GimpyFactory(dictionnaryWords, word2image));
}
} 前臺JSP
后臺Action驗證
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