Java tutorial
/* * Symphony - A modern community (forum/SNS/blog) platform written in Java. * Copyright (C) 2012-2016, b3log.org & hacpai.com * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package org.b3log.symphony.processor; import java.io.BufferedInputStream; import java.io.File; import java.io.FileOutputStream; import java.io.InputStream; import java.io.OutputStream; import java.net.URL; import java.util.Enumeration; import java.util.Random; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import org.apache.commons.io.IOUtils; import org.apache.commons.lang.StringUtils; import org.b3log.latke.Latkes; import org.b3log.latke.RuntimeEnv; import org.b3log.latke.image.Image; import org.b3log.latke.image.ImageService; import org.b3log.latke.image.ImageServiceFactory; import org.b3log.latke.logging.Level; import org.b3log.latke.logging.Logger; import org.b3log.latke.servlet.HTTPRequestContext; import org.b3log.latke.servlet.HTTPRequestMethod; import org.b3log.latke.servlet.annotation.RequestProcessing; import org.b3log.latke.servlet.annotation.RequestProcessor; import org.b3log.latke.servlet.renderer.PNGRenderer; import org.b3log.symphony.SymphonyServletListener; import org.b3log.symphony.model.Common; import org.json.JSONObject; /** * Captcha processor. * * <p> * Checkout <a href="http://toy-code.googlecode.com/svn/trunk/CaptchaGenerator"> * the sample captcha generator</a> for more details. * </p> * * @author <a href="http://88250.b3log.org">Liang Ding</a> * @version 1.2.0.5, Nov 1, 2016 * @since 0.2.2 */ @RequestProcessor public class CaptchaProcessor { /** * Logger. */ private static final Logger LOGGER = Logger.getLogger(CaptchaProcessor.class.getName()); /** * Images service. */ private static final ImageService IMAGE_SERVICE = ImageServiceFactory.getImageService(); /** * Key of captcha. */ public static final String CAPTCHA = "captcha"; /** * Captchas. */ private Image[] captchas; /** * Count of static captchas. */ private static final int CAPTCHA_COUNT = 100; /** * Gets captcha. * * @param context the specified context */ @RequestProcessing(value = "/captcha", method = HTTPRequestMethod.GET) public void get(final HTTPRequestContext context) { final PNGRenderer renderer = new PNGRenderer(); context.setRenderer(renderer); if (null == captchas) { loadCaptchas(); } try { final HttpServletRequest request = context.getRequest(); final HttpServletResponse response = context.getResponse(); final Random random = new Random(); final int index = random.nextInt(CAPTCHA_COUNT); final Image captchaImg = captchas[index]; final String captcha = captchaImg.getName(); final HttpSession httpSession = request.getSession(false); if (null != httpSession) { LOGGER.log(Level.DEBUG, "Captcha[{0}] for session[id={1}]", new Object[] { captcha, httpSession.getId() }); httpSession.setAttribute(CAPTCHA, captcha); } response.setHeader("Pragma", "no-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); renderer.setImage(captchaImg); } catch (final Exception e) { LOGGER.log(Level.ERROR, e.getMessage(), e); } } /** * Gets captcha for login. * * @param context the specified context */ @RequestProcessing(value = "/captcha/login", method = HTTPRequestMethod.GET) public void getLoginCaptcha(final HTTPRequestContext context) { if (null == captchas) { loadCaptchas(); } try { final HttpServletRequest request = context.getRequest(); final HttpServletResponse response = context.getResponse(); final String userId = request.getParameter(Common.NEED_CAPTCHA); if (StringUtils.isBlank(userId)) { return; } final JSONObject wrong = LoginProcessor.WRONG_PWD_TRIES.get(userId); if (null == wrong) { return; } if (wrong.optInt(Common.WRON_COUNT) < 3) { return; } final PNGRenderer renderer = new PNGRenderer(); context.setRenderer(renderer); final Random random = new Random(); final int index = random.nextInt(CAPTCHA_COUNT); final Image captchaImg = captchas[index]; final String captcha = captchaImg.getName(); wrong.put(CAPTCHA, captcha); response.setHeader("Pragma", "no-cache"); response.setHeader("Cache-Control", "no-cache"); response.setDateHeader("Expires", 0); renderer.setImage(captchaImg); } catch (final Exception e) { LOGGER.log(Level.ERROR, e.getMessage(), e); } } /** * Loads captcha. */ private synchronized void loadCaptchas() { LOGGER.trace("Loading captchas...."); try { captchas = new Image[CAPTCHA_COUNT]; ZipFile zipFile; if (RuntimeEnv.LOCAL == Latkes.getRuntimeEnv()) { final InputStream inputStream = SymphonyServletListener.class.getClassLoader() .getResourceAsStream("captcha_static.zip"); final File file = File.createTempFile("b3log_captcha_static", null); final OutputStream outputStream = new FileOutputStream(file); IOUtils.copy(inputStream, outputStream); zipFile = new ZipFile(file); IOUtils.closeQuietly(inputStream); IOUtils.closeQuietly(outputStream); } else { final URL captchaURL = SymphonyServletListener.class.getClassLoader() .getResource("captcha_static.zip"); zipFile = new ZipFile(captchaURL.getFile()); } final Enumeration<? extends ZipEntry> entries = zipFile.entries(); int i = 0; while (entries.hasMoreElements()) { final ZipEntry entry = entries.nextElement(); final BufferedInputStream bufferedInputStream = new BufferedInputStream( zipFile.getInputStream(entry)); final byte[] captchaCharData = new byte[bufferedInputStream.available()]; bufferedInputStream.read(captchaCharData); bufferedInputStream.close(); final Image image = IMAGE_SERVICE.makeImage(captchaCharData); image.setName(entry.getName().substring(0, entry.getName().lastIndexOf('.'))); captchas[i] = image; i++; } zipFile.close(); } catch (final Exception e) { LOGGER.error("Can not load captchs!"); throw new IllegalStateException(e); } LOGGER.trace("Loaded captch images"); } }