Java tutorial
/** * ========================================================================================== * = JAHIA'S DUAL LICENSING - IMPORTANT INFORMATION = * ========================================================================================== * * http://www.jahia.com * * Copyright (C) 2002-2017 Jahia Solutions Group SA. All rights reserved. * * THIS FILE IS AVAILABLE UNDER TWO DIFFERENT LICENSES: * 1/GPL OR 2/JSEL * * 1/ GPL * ================================================================================== * * IF YOU DECIDE TO CHOOSE THE GPL LICENSE, YOU MUST COMPLY WITH THE FOLLOWING TERMS: * * 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/>. * * * 2/ JSEL - Commercial and Supported Versions of the program * =================================================================================== * * IF YOU DECIDE TO CHOOSE THE JSEL LICENSE, YOU MUST COMPLY WITH THE FOLLOWING TERMS: * * Alternatively, commercial and supported versions of the program - also known as * Enterprise Distributions - must be used in accordance with the terms and conditions * contained in a separate written agreement between you and Jahia Solutions Group SA. * * If you are unsure which license is appropriate for your use, * please contact the sales department at sales@jahia.com. */ package org.jahia.services.notification; import java.util.List; import java.util.regex.Pattern; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import net.htmlparser.jericho.Attribute; import net.htmlparser.jericho.Attributes; import net.htmlparser.jericho.Element; import net.htmlparser.jericho.HTMLElementName; import net.htmlparser.jericho.OutputDocument; import net.htmlparser.jericho.Source; import net.htmlparser.jericho.StartTag; import org.apache.commons.io.IOUtils; import org.apache.commons.lang.StringUtils; import org.slf4j.Logger; import org.jahia.data.templates.JahiaTemplatesPackage; import org.jahia.registries.ServicesRegistry; import org.jahia.services.render.RenderContext; import org.jahia.services.render.Resource; import org.jahia.services.render.filter.HtmlTagAttributeTraverser; import org.jahia.services.render.filter.HtmlTagAttributeTraverser.HtmlTagAttributeVisitor; /** * Service used to "externalizes" the HTML document content by converting all * local URLs into absolute, inlining external CSS styles, and rewriting URLs in * CSS. * * @author Sergiy Shyrkov */ public class HtmlExternalizationService { protected static final Pattern CSS_URL_PATTERN = Pattern.compile("url *\\( *\"?([^\\:\" )]*)\"? *\\)"); private static final Logger logger = org.slf4j.LoggerFactory.getLogger(HtmlExternalizationService.class); private HttpClientService httpClientService; private boolean inlineCss = true; private boolean removeExternalScripts = true; private boolean removeInlinedScripts = true; private boolean rewriteUrls = true; private boolean rewriteUrlsInCss = true; private HtmlTagAttributeTraverser urlTraverser; private boolean useServletContextResources = true; public String externalize(String sourceContent, RenderContext renderContext) { return externalize(sourceContent, renderContext.getURLGenerator().getServer(), renderContext.getRequest(), renderContext.getResponse()); } public String externalize(String sourceContent, String serverUrl) { return externalize(sourceContent, serverUrl, null, null); } public String externalize(String sourceContent, String serverUrl, HttpServletRequest request, HttpServletResponse response) { String out = sourceContent; long timer = System.currentTimeMillis(); if (removeExternalScripts || removeInlinedScripts) { out = removeJavaScript(out); } if (inlineCss) { // process CSS out = processCss(out, serverUrl, request, response); } if (rewriteUrls) { // process URLs out = rewriteUrls(out, serverUrl); if (logger.isDebugEnabled()) { logger.debug("...done processing URLs in " + (System.currentTimeMillis() - timer) + " ms"); } } if (logger.isDebugEnabled()) { logger.info("...done externalizing output content in " + (System.currentTimeMillis() - timer) + " ms"); } return out; } protected String processCss(String previousOut, String serverUrl, HttpServletRequest request, HttpServletResponse response) { Source source = new Source(previousOut); OutputDocument document = new OutputDocument(source); StringBuilder sb = new StringBuilder(); List<StartTag> linkStartTags = source.getAllStartTags(HTMLElementName.LINK); for (StartTag linkTag : linkStartTags) { Attributes attributes = linkTag.getAttributes(); String rel = attributes.getValue("rel"); if (rel == null || !"stylesheet".equalsIgnoreCase(rel)) { continue; } String href = attributes.getValue("href"); if (href == null) { continue; } String styleSheetContent = null; try { if (useServletContextResources || request == null || response == null) { if (request != null && StringUtils.startsWith(href, request.getContextPath())) { href = StringUtils.substringAfter(href, request.getContextPath()); } if (href.startsWith("/modules/")) { String after = StringUtils.substringAfter(href, "/modules/"); String module = StringUtils.substringBefore(after, "/"); JahiaTemplatesPackage pack = ServicesRegistry.getInstance().getJahiaTemplateManagerService() .getTemplatePackageById(module); if (pack != null) { String prefix = "/modules/" + module; if (!href.startsWith(prefix)) { href = prefix + "/" + StringUtils.substringAfter(after, "/"); } styleSheetContent = StringUtils.join(IOUtils.readLines( pack.getResource(StringUtils.substringAfter(after, "/")).getInputStream()), '\n'); } } else { styleSheetContent = httpClientService.getResourceAsString(href); } } else { styleSheetContent = httpClientService.getResourceAsString(href, request, response); } } catch (Exception e) { logger.warn("Unable to retrieve resource content for " + href + ".Cause: " + e.getMessage(), e); } if (StringUtils.isNotEmpty(styleSheetContent)) { sb.setLength(0); sb.append("<style"); Attribute typeAttribute = attributes.get("type"); if (typeAttribute != null) { sb.append(' ').append(typeAttribute); } if (rewriteUrlsInCss) { String baseUrl = HttpClientService.isAbsoluteUrl(href) ? href : serverUrl + href; baseUrl = StringUtils.substringBeforeLast(baseUrl, "/") + "/"; styleSheetContent = rewriteCssUrls(styleSheetContent, baseUrl); } sb.append(">\n"); if (request != null && Boolean.valueOf(request.getParameter("debug"))) { sb.append("/* ").append(href).append(" */\n"); } sb.append(styleSheetContent).append("\n</style>"); document.replace(linkTag, sb.toString()); } } return document.toString(); } protected String removeJavaScript(String out) { Source source = new Source(out); OutputDocument document = new OutputDocument(source); List<Element> scriptTags = source.getAllElements(HTMLElementName.SCRIPT); for (Element scriptElement : scriptTags) { boolean doRemove = false; if (removeExternalScripts && removeInlinedScripts) { doRemove = true; } else { String srcAttr = scriptElement.getAttributeValue("src"); doRemove = removeExternalScripts && StringUtils.isNotEmpty(srcAttr) || removeInlinedScripts && StringUtils.isEmpty(srcAttr); } if (doRemove) { document.remove(scriptElement); } } return document.toString(); } /** * Replaces the relative URLs in CSS content into absolute form. * * @param cssContent the original CSS content * @param urlBase the base URL to use for rewriting * @return the rewritten CSS content */ protected String rewriteCssUrls(String cssContent, String urlBase) { return CSS_URL_PATTERN.matcher(cssContent).replaceAll("url(\"" + urlBase + "$1\")"); } protected String rewriteUrls(String source, final String serverUrl) { return urlTraverser.traverse(source, new HtmlTagAttributeVisitor() { public String visit(String url, RenderContext context, String tagName, String attrName, Resource resource) { return StringUtils.isNotEmpty(url) && url.startsWith("/") ? serverUrl + url : url; } }); } /** * @param httpClientService the httpClientService to set */ public void setHttpClientService(HttpClientService httpClientService) { this.httpClientService = httpClientService; } /** * @param inlineCss the inlineCss to set */ public void setInlineCss(boolean inlineCss) { this.inlineCss = inlineCss; } /** * @param removeExternalScripts the removeExternalScripts to set */ public void setRemoveExternalScripts(boolean removeExternalScripts) { this.removeExternalScripts = removeExternalScripts; } /** * @param removeInlinedScripts the removeInlinedScripts to set */ public void setRemoveInlinedScripts(boolean removeInlinedScripts) { this.removeInlinedScripts = removeInlinedScripts; } /** * @param rewriteUrls the rewriteUrls to set */ public void setRewriteUrls(boolean rewriteUrls) { this.rewriteUrls = rewriteUrls; } /** * @param rewriteUrlsInCss the rewriteUrlsInCss to set */ public void setRewriteUrlsInCss(boolean rewriteUrlsInCss) { this.rewriteUrlsInCss = rewriteUrlsInCss; } /** * @param urlTraverser the urlTraverser to set */ public void setUrlTraverser(HtmlTagAttributeTraverser urlTraverser) { this.urlTraverser = urlTraverser; } /** * @param useServletContextResources the useServletContextResources to set */ public void setUseServletContextResources(boolean useServletContextResources) { this.useServletContextResources = useServletContextResources; } }