Java tutorial
/** * Copyright (C) 2011 JTalks.org Team * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * This library 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 * Lesser General Public License for more details. * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ package org.jtalks.jcommune.plugin.kaptcha; import com.google.code.kaptcha.Constants; import com.google.code.kaptcha.Producer; import com.google.code.kaptcha.impl.DefaultKaptcha; import com.google.code.kaptcha.util.Config; import com.google.common.collect.ImmutableMap; import org.apache.commons.lang.StringUtils; import org.apache.velocity.app.VelocityEngine; import org.apache.velocity.tools.generic.DateTool; import org.jtalks.jcommune.model.dto.UserDto; import org.springframework.security.core.context.SecurityContextHolder; import org.springframework.ui.velocity.VelocityEngineUtils; import org.springframework.web.context.request.RequestAttributes; import org.springframework.web.context.request.RequestContextHolder; import org.springframework.web.context.request.ServletRequestAttributes; import javax.imageio.ImageIO; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import java.awt.image.BufferedImage; import java.io.IOException; import java.util.*; /** * Serves for processing basic captcha functionality, such as refresh captcha, validate captcha and get captcha as html. * * @author Andrey Pogorelov */ public class KaptchaPluginService { private static final String CAPTCHA_LABEL = "captchaLabel"; private static final String ALT_CAPTCHA = "altCaptcha"; private static final String ALT_REFRESH_CAPTCHA = "altRefreshCaptcha"; private static final String CAPTCHA_PLUGIN_ID = "captchaPluginId"; private static final String BASE_URL = "baseUrl"; private static final String FORM_ELEMENT_ID = "formElementId"; private static final String PLUGIN_PREFIX = "plugin-"; private static final String DATE = "date"; private Producer captchaProducer; public KaptchaPluginService(int width, int height, int length, String possibleSymbols) { captchaProducer = createCaptchaProducer(width, height, length, possibleSymbols); } /** * Get plugin input element id for registration form. * * @param pluginId plugin id * @return form element id */ private String getFormElementId(String pluginId) { return PLUGIN_PREFIX + pluginId; } /** * Get plugin field name for registration form. * * @param pluginId plugin id * @return field name */ private String getFormFieldName(String pluginId) { return "userDto.captchas['" + (PLUGIN_PREFIX + pluginId) + "']"; } /** * Validates captcha value. * * @param userDto user container with captcha * @param pluginId plugin id * @return validation errors */ public Map<String, String> validateCaptcha(UserDto userDto, Long pluginId) { String captcha = userDto.getCaptchas().get(getFormElementId(String.valueOf(pluginId))); if (!isValid(captcha)) { ResourceBundle resourceBundle = ResourceBundle.getBundle("org.jtalks.jcommune.plugin.kaptcha.messages", userDto.getLanguage().getLocale()); String fieldName = getFormFieldName(String.valueOf(pluginId)); return new ImmutableMap.Builder<String, String>() .put(fieldName, resourceBundle.getString("validation.captcha.wrong")).build(); } return new HashMap<>(); } /** * Checks if specified captcha value is the same as a captcha showed to user. * * @param value submitted captcha value * @return success */ private boolean isValid(String value) { String sessionCaptchaId = (String) getSession().getAttribute(Constants.KAPTCHA_SESSION_KEY); return sessionCaptchaId != null && StringUtils.equals(sessionCaptchaId, value); } protected Properties getProperties() { Properties properties = new Properties(); properties.put("resource.loader", "jar"); properties.put("jar.resource.loader.class", "org.apache.velocity.runtime.resource.loader.JarResourceLoader"); String jarPath = this.getClass().getProtectionDomain().getCodeSource().getLocation().getPath(); properties.put("jar.resource.loader.path", "jar:file:" + jarPath); properties.put("runtime.log.logsystem.class", "org.apache.velocity.runtime.log.NullLogSystem"); return properties; } public String getHtml(HttpServletRequest request, String pluginId, Locale locale) { SecurityContextHolder.getContext(); ResourceBundle resourceBundle = ResourceBundle.getBundle("org.jtalks.jcommune.plugin.kaptcha.messages", locale); VelocityEngine engine = new VelocityEngine(getProperties()); engine.init(); Map<String, Object> model = new HashMap<>(); model.put(CAPTCHA_LABEL, resourceBundle.getObject("label.tip.captcha")); model.put(ALT_CAPTCHA, resourceBundle.getObject("alt.captcha.image")); model.put(ALT_REFRESH_CAPTCHA, resourceBundle.getObject("alt.captcha.update")); model.put(CAPTCHA_PLUGIN_ID, pluginId); model.put(FORM_ELEMENT_ID, getFormElementId(pluginId)); model.put(BASE_URL, getDeploymentRootUrl(request)); model.put(DATE, new DateTool()); return VelocityEngineUtils.mergeTemplateIntoString(engine, "org/jtalks/jcommune/plugin/kaptcha/template/captcha.vm", "UTF-8", model); } private Producer createCaptchaProducer(int width, int height, int length, String possibleSymbols) { Properties props = new Properties(); props.setProperty("kaptcha.textproducer.char.string", possibleSymbols); props.setProperty("kaptcha.textproducer.char.length", String.valueOf(length)); props.setProperty("kaptcha.image.width", String.valueOf(width)); props.setProperty("kaptcha.image.height", String.valueOf(height)); Config conf = new Config(props); DefaultKaptcha captcha = new DefaultKaptcha(); captcha.setConfig(conf); return captcha; } protected Producer getCaptchaProducer() { return this.captchaProducer; } /** * Refresh captcha image on registration form. * * @param request http request * @param response http response * @throws IOException */ public void refreshCaptchaImage(HttpServletRequest request, HttpServletResponse response) throws IOException { ServletOutputStream out = response.getOutputStream(); response.setContentType("image/jpeg"); String capText = getCaptchaProducer().createText(); request.getSession().setAttribute(Constants.KAPTCHA_SESSION_KEY, capText); BufferedImage bi = getCaptchaProducer().createImage(capText); ImageIO.write(bi, "jpg", out); out.flush(); } /** * Returns current deployment root with port (if required) for using as label link, for example. * * @return current deployment root with port, e.g. "http://myhost.com:8080/myforum" or "http://myhost.com/myforum" */ protected String getDeploymentRootUrl(HttpServletRequest request) { StringBuilder urlBuilder = new StringBuilder().append(request.getScheme()).append("://") .append(request.getServerName()); if (request.getServerPort() != 80) { urlBuilder.append(":").append(request.getServerPort()); } urlBuilder.append(request.getContextPath()); return urlBuilder.toString(); } /** * Remove current captcha in session */ public void removeCurrentCaptcha() { getSession().removeAttribute(Constants.KAPTCHA_SESSION_KEY); } private HttpSession getSession() { RequestAttributes attributes = RequestContextHolder.currentRequestAttributes(); return ((ServletRequestAttributes) attributes).getRequest().getSession(); } }