Java tutorial
/** * This file Copyright (c) 2003-2012 Magnolia International * Ltd. (http://www.magnolia-cms.com). All rights reserved. * * * This file is dual-licensed under both the Magnolia * Network Agreement and the GNU General Public License. * You may elect to use one or the other of these licenses. * * This file is distributed in the hope that it will be * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the * implied warranty of MERCHANTABILITY or FITNESS FOR A * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT. * Redistribution, except as permitted by whichever of the GPL * or MNA you select, is prohibited. * * 1. For the GPL license (GPL), you can redistribute and/or * modify this file under the terms of the GNU General * Public License, Version 3, as published by the Free Software * Foundation. You should have received a copy of the GNU * General Public License, Version 3 along with this program; * if not, write to the Free Software Foundation, Inc., 51 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * 2. For the Magnolia Network Agreement (MNA), this file * and the accompanying materials are made available under the * terms of the MNA which accompanies this distribution, and * is available at http://www.magnolia-cms.com/mna.html * * Any modifications to this file must keep this entire header * intact. * */ package info.magnolia.rendering.engine; import info.magnolia.cms.core.AggregationState; import info.magnolia.cms.filters.AbstractMgnlFilter; import info.magnolia.context.MgnlContext; import info.magnolia.jcr.wrapper.ChannelVisibilityContentDecorator; import info.magnolia.registry.RegistrationException; import info.magnolia.rendering.template.TemplateDefinition; import info.magnolia.rendering.template.registry.TemplateDefinitionRegistry; import java.io.IOException; import java.io.InputStream; import java.util.Collections; import javax.jcr.Node; import javax.jcr.Property; import javax.jcr.RepositoryException; import javax.jcr.Session; import javax.servlet.FilterChain; import javax.servlet.ServletException; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.io.IOUtils; import org.apache.commons.lang.StringUtils; import org.apache.commons.lang.math.NumberUtils; import org.apache.jackrabbit.JcrConstants; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Filter responsible for rendering the current aggregation state, * by delegating to the appropriate TemplateRenderer or by serving * binary content. */ public class RenderingFilter extends AbstractMgnlFilter { private static final Logger log = LoggerFactory.getLogger(RenderingFilter.class); private final RenderingEngine renderingEngine; private final TemplateDefinitionRegistry templateDefinitionRegistry; public RenderingFilter(RenderingEngine renderingEngine, TemplateDefinitionRegistry templateDefinitionRegistry) { this.renderingEngine = renderingEngine; this.templateDefinitionRegistry = templateDefinitionRegistry; } @Override public void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException { final AggregationState aggregationState = MgnlContext.getAggregationState(); String templateName = aggregationState.getTemplateName(); if (StringUtils.isNotEmpty(templateName)) { try { // don't reset any existing status code, see MAGNOLIA-2005 // response.setStatus(HttpServletResponse.SC_OK); if (response != MgnlContext.getWebContext().getResponse()) { log.warn("Context response not synced. This may lead to discrepancies in rendering."); } Node content = aggregationState.getMainContent().getJCRNode(); // if the content isn't visible output a 404 if (!isVisible(content, request, response, aggregationState)) { if (!response.isCommitted()) { response.sendError(HttpServletResponse.SC_NOT_FOUND); } else { log.info("Unable to redirect to 404 page for {}, response is already committed", request.getRequestURI()); } return; } render(content, templateName, response); try { response.flushBuffer(); } catch (IOException e) { // don't log at error level since tomcat typically throws a // org.apache.catalina.connector.ClientAbortException if the user stops loading the page log.debug("Exception flushing response " + e.getClass().getName() + ": " + e.getMessage(), e); } } catch (RenderException e) { // TODO better handling of rendering exception // TODO dlipp: why not move this section up to the actual call to render() -> that's the only place where a RenderException could occur... log.error(e.getMessage(), e); throw new ServletException(e); } catch (Exception e) { // TODO dlipp: there's no other checked exceptions thrown in the code above - is it correct to react like that??? log.error(e.getMessage(), e); if (!response.isCommitted()) { response.setContentType("text/html"); } throw new RuntimeException(e); } } else { // direct request handleResourceRequest(aggregationState, request, response); } // TODO don't make it a dead end // currently we can't process the chain because there is no content/nop servlet // chain.doFilter(request, response); } protected boolean isVisible(Node content, HttpServletRequest request, HttpServletResponse response, AggregationState aggregationState) { // if there's a channel set test if the content is excluded for the current channel if (aggregationState.getChannel() != null) { String currentChannel = aggregationState.getChannel().getName(); if (StringUtils.isNotEmpty(currentChannel) && !currentChannel.equalsIgnoreCase("all")) { ChannelVisibilityContentDecorator decorator = new ChannelVisibilityContentDecorator(currentChannel); return decorator.evaluateNode(content); } } return true; } protected void render(Node content, String templateName, HttpServletResponse response) throws RenderException { TemplateDefinition templateDefinition; try { templateDefinition = templateDefinitionRegistry.getTemplateDefinition(templateName); } catch (RegistrationException e) { throw new RenderException(e); } renderingEngine.render(content, templateDefinition, Collections.<String, Object>emptyMap(), new ResponseOutputProvider(response)); } /** * Get the requested resource and copy it to the ServletOutputStream, bit by bit. * @param request HttpServletRequest as given by the servlet container * @param response HttpServletResponse as given by the servlet container * @throws IOException standard servlet exception */ protected void handleResourceRequest(AggregationState aggregationState, HttpServletRequest request, HttpServletResponse response) throws IOException { final String resourceHandle = aggregationState.getHandle(); log.debug("handleResourceRequest, resourceHandle=\"{}\"", resourceHandle); if (StringUtils.isNotEmpty(resourceHandle)) { InputStream is = null; try { Session session = MgnlContext.getJCRSession(aggregationState.getRepository()); is = getNodedataAsStream(resourceHandle, session, response); if (null != is) { // don't reset any existing status code, see MAGNOLIA-2005 // response.setStatus(HttpServletResponse.SC_OK); sendUnCompressed(is, response); IOUtils.closeQuietly(is); return; } } catch (IOException e) { // don't log at error level since tomcat tipically throws a // org.apache.catalina.connector.ClientAbortException if the user stops loading the page log.debug("Exception while dispatching resource " + e.getClass().getName() + ": " + e.getMessage(), e); return; } catch (Exception e) { log.error("Exception while dispatching resource " + e.getClass().getName() + ": " + e.getMessage(), e); return; } finally { IOUtils.closeQuietly(is); } } log.debug("Resource not found, redirecting request for [{}] to 404 URI", request.getRequestURI()); if (!response.isCommitted()) { response.sendError(HttpServletResponse.SC_NOT_FOUND); } else { log.info("Unable to redirect to 404 page for {}, response is already committed", request.getRequestURI()); } } /** * Send data as is. * @param is Input stream for the resource * @param response HttpServletResponse as received by the service method * @throws IOException standard servlet exception */ private void sendUnCompressed(InputStream is, HttpServletResponse response) throws IOException { ServletOutputStream os = response.getOutputStream(); byte[] buffer = new byte[8192]; int read; while ((read = is.read(buffer)) > 0) { os.write(buffer, 0, read); } os.flush(); IOUtils.closeQuietly(os); } private InputStream getNodedataAsStream(String path, Session session, HttpServletResponse res) { log.debug("getNodedataAstream for path \"{}\"", path); try { Node atom = session.getNode(path); if (atom != null) { if (atom.hasProperty(JcrConstants.JCR_DATA)) { Property sizeProperty = atom.getProperty("size"); String sizeString = sizeProperty == null ? "" : sizeProperty.getString(); if (NumberUtils.isNumber(sizeString)) { res.setContentLength(Integer.parseInt(sizeString)); } Property streamProperty = atom.getProperty(JcrConstants.JCR_DATA); return streamProperty.getStream(); } } log.warn("Resource not found: [{}]", path); } catch (RepositoryException e) { log.error("RepositoryException while reading Resource [" + path + "]", e); } return null; } }