Java tutorial
/** * This file is part of "Metamesh RFS Driver for OpenCms". * * "Metamesh RFS Driver for OpenCms" 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. * "Metamesh RFS Driver for OpenCms" 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 "Metamesh RFS Driver for OpenCms". * If not, see <http://www.gnu.org/licenses/>. * * * Copyright (c) Stephan Hartmann (http://www.metamesh.com) * */ package com.metamesh.opencms.rfs; import org.opencms.file.CmsFile; import org.opencms.file.CmsObject; import org.opencms.file.CmsResource; import org.opencms.flex.CmsFlexController; import org.opencms.loader.I_CmsResourceLoader; import org.opencms.loader.Messages; import org.opencms.main.CmsException; import org.opencms.main.CmsLog; import org.opencms.main.OpenCms; import org.opencms.util.CmsRequestUtil; import org.opencms.util.CmsStringUtil; import org.opencms.workplace.CmsWorkplaceManager; import java.io.FileInputStream; import java.io.IOException; import java.util.Collections; import java.util.Iterator; import java.util.Locale; import java.util.Map; import java.util.TreeMap; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.collections.ExtendedProperties; public class RfsFileLoader implements I_CmsResourceLoader { /** The id of this loader. */ public static final int RESOURCE_LOADER_ID = 45538; /** The maximum age for dumped contents in the clients cache. */ private static long m_clientCacheMaxAge; /** The resource loader configuration. */ private Map m_configuration; /** * The constructor of the class is empty and does nothing.<p> */ public RfsFileLoader() { m_configuration = new TreeMap(); } /** * @see org.opencms.configuration.I_CmsConfigurationParameterHandler#addConfigurationParameter(java.lang.String, java.lang.String) */ public void addConfigurationParameter(String paramName, String paramValue) { m_configuration.put(paramName, paramValue); } /** * Destroy this ResourceLoder, this is a NOOP so far.<p> */ public void destroy() { // NOOP } /** * @see org.opencms.loader.I_CmsResourceLoader#dump(org.opencms.file.CmsObject, org.opencms.file.CmsResource, java.lang.String, java.util.Locale, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) */ public byte[] dump(CmsObject cms, CmsResource resource, String element, Locale locale, HttpServletRequest req, HttpServletResponse res) throws CmsException { return cms.readFile(resource).getContents(); } /** * @see org.opencms.loader.I_CmsResourceLoader#export(org.opencms.file.CmsObject, org.opencms.file.CmsResource, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) */ public byte[] export(CmsObject cms, CmsResource resource, HttpServletRequest req, HttpServletResponse res) throws IOException, CmsException { CmsFile file = cms.readFile(resource); // if no request and response are given, the resource only must be exported and no // output must be generated if ((req != null) && (res != null)) { // overwrite headers if set as default for (Iterator i = OpenCms.getStaticExportManager().getExportHeaders().listIterator(); i.hasNext();) { String header = (String) i.next(); // set header only if format is "key: value" String[] parts = CmsStringUtil.splitAsArray(header, ':'); if (parts.length == 2) { res.setHeader(parts[0], parts[1]); } } load(cms, file, req, res); } return file.getContents(); } /** * Will always return <code>null</code> since this loader does not * need to be configured.<p> * * @see org.opencms.configuration.I_CmsConfigurationParameterHandler#getConfiguration() */ public Map getConfiguration() { // return the configuration in an immutable form return Collections.unmodifiableMap(m_configuration); } /** * @see org.opencms.loader.I_CmsResourceLoader#getLoaderId() */ public int getLoaderId() { return RESOURCE_LOADER_ID; } public String getResourceLoaderInfo() { return "RFS File Loader"; } /** * @see org.opencms.configuration.I_CmsConfigurationParameterHandler#initConfiguration() */ public void initConfiguration() { ExtendedProperties config = new ExtendedProperties(); config.putAll(m_configuration); String maxAge = config.getString("client.cache.maxage"); if (maxAge == null) { m_clientCacheMaxAge = -1; } else { m_clientCacheMaxAge = Long.parseLong(maxAge); } if (CmsLog.INIT.isInfoEnabled()) { if (maxAge != null) { CmsLog.INIT.info(Messages.get().getBundle().key(Messages.INIT_CLIENT_CACHE_MAX_AGE_1, maxAge)); } CmsLog.INIT.info( Messages.get().getBundle().key(Messages.INIT_LOADER_INITIALIZED_1, this.getClass().getName())); } } /** * @see org.opencms.loader.I_CmsResourceLoader#isStaticExportEnabled() */ public boolean isStaticExportEnabled() { return false; } /** * @see org.opencms.loader.I_CmsResourceLoader#isStaticExportProcessable() */ public boolean isStaticExportProcessable() { return false; } /** * @see org.opencms.loader.I_CmsResourceLoader#isUsableForTemplates() */ public boolean isUsableForTemplates() { return false; } /** * @see org.opencms.loader.I_CmsResourceLoader#isUsingUriWhenLoadingTemplate() */ public boolean isUsingUriWhenLoadingTemplate() { return false; } /** * @see org.opencms.loader.I_CmsResourceLoader#load(org.opencms.file.CmsObject, org.opencms.file.CmsResource, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse) */ public void load(CmsObject cms, CmsResource resource, HttpServletRequest req, HttpServletResponse res) throws IOException, CmsException { if (canSendLastModifiedHeader(resource, req, res)) { // no further processing required return; } // set response status to "200 - OK" (required for static export "on-demand") res.setStatus(HttpServletResponse.SC_OK); // set content length header res.setContentLength(resource.getLength()); if (CmsWorkplaceManager.isWorkplaceUser(req)) { // prevent caching for Workplace users res.setDateHeader(CmsRequestUtil.HEADER_LAST_MODIFIED, System.currentTimeMillis()); CmsRequestUtil.setNoCacheHeaders(res); } else { // set date last modified header res.setDateHeader(CmsRequestUtil.HEADER_LAST_MODIFIED, resource.getDateLastModified()); // set "Expires" only if cache control is not already set if (!res.containsHeader(CmsRequestUtil.HEADER_CACHE_CONTROL)) { long expireTime = resource.getDateExpired(); if (expireTime == CmsResource.DATE_EXPIRED_DEFAULT) { expireTime--; // flex controller will automatically reduce this to a reasonable value } // now set "Expires" header CmsFlexController.setDateExpiresHeader(res, expireTime, m_clientCacheMaxAge); } } service(cms, resource, req, res); } /** * @see org.opencms.loader.I_CmsResourceLoader#service(org.opencms.file.CmsObject, org.opencms.file.CmsResource, javax.servlet.ServletRequest, javax.servlet.ServletResponse) */ public void service(CmsObject cms, CmsResource resource, ServletRequest req, ServletResponse res) throws CmsException, IOException { RfsFile rfsFile = (RfsFile) resource; FileInputStream fis = null; try { fis = new FileInputStream(rfsFile.getRfsPath()); byte[] buffy = new byte[4096]; int bytesRead; while ((bytesRead = fis.read(buffy)) >= 0) { res.getOutputStream().write(buffy, 0, bytesRead); res.getOutputStream().flush(); } } finally { if (fis != null) { fis.close(); } } } /** * Checks if the requested resource must be send to the client by checking the "If-Modified-Since" http header.<p> * * If the resource has not been modified, the "304 - not modified" * header is send to the client and <code>true</code> * is returned, otherwise nothing is send and <code>false</code> is returned.<p> * * @param resource the resource to check * @param req the current request * @param res the current response * * @return <code>true</code> if the "304 - not modified" header has been send to the client */ protected boolean canSendLastModifiedHeader(CmsResource resource, HttpServletRequest req, HttpServletResponse res) { // resource state must be unchanged if (resource.getState().isUnchanged() // the request must not have been send by a workplace user (we can't use "304 - not modified" in workplace && !CmsWorkplaceManager.isWorkplaceUser(req) // last modified header must match the time form the resource && CmsFlexController.isNotModifiedSince(req, resource.getDateLastModified())) { long now = System.currentTimeMillis(); if ((resource.getDateReleased() < now) && (resource.getDateExpired() > now)) { // resource is available and not expired CmsFlexController.setDateExpiresHeader(res, resource.getDateExpired(), m_clientCacheMaxAge); // set status 304 - not modified res.setStatus(HttpServletResponse.SC_NOT_MODIFIED); return true; } } return false; } }