Java tutorial
/* * This library is part of OpenCms - * the Open Source Content Management System * * Copyright (c) Alkacon Software GmbH (http://www.alkacon.com) * * 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. * * For further information about Alkacon Software GmbH, please see the * company website: http://www.alkacon.com * * For further information about OpenCms, please see the * project website: http://www.opencms.org * * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ package org.opencms.flex; import org.opencms.file.CmsObject; import org.opencms.file.CmsResource; import org.opencms.main.CmsLog; import org.opencms.util.CmsRequestUtil; import java.util.List; import java.util.Vector; import javax.servlet.ServletRequest; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.apache.commons.logging.Log; /** * Controller for getting access to the CmsObject, should be used as a * request attribute.<p> * * @since 6.0.0 */ public class CmsFlexController { /** Constant for the controller request attribute name. */ public static final String ATTRIBUTE_NAME = "org.opencms.flex.CmsFlexController"; /** The log object for this class. */ private static final Log LOG = CmsLog.getLog(CmsFlexController.class); /** The CmsFlexCache where the result will be cached in, required for the dispatcher. */ private CmsFlexCache m_cache; /** The wrapped CmsObject provides JSP with access to the core system. */ private CmsObject m_cmsObject; /** List of wrapped RequestContext info object. */ private List<CmsFlexRequestContextInfo> m_flexContextInfoList; /** List of wrapped CmsFlexRequests. */ private List<CmsFlexRequest> m_flexRequestList; /** List of wrapped CmsFlexResponses. */ private List<CmsFlexResponse> m_flexResponseList; /** Indicates if this controller is currently in "forward" mode. */ private boolean m_forwardMode; /** Wrapped top request. */ private HttpServletRequest m_req; /** Wrapped top response. */ private HttpServletResponse m_res; /** The CmsResource that was initialized by the original request, required for URI actions. */ private CmsResource m_resource; /** Indicates if the response should be streamed. */ private boolean m_streaming; /** Exception that was caught during inclusion of sub elements. */ private Throwable m_throwable; /** URI of a VFS resource that caused the exception. */ private String m_throwableResourceUri; /** Indicates if the request is the top request. */ private boolean m_top; /** * Creates a new controller form the old one, exchanging just the provided OpenCms user context.<p> * * @param cms the OpenCms user context for this controller * @param base the base controller */ public CmsFlexController(CmsObject cms, CmsFlexController base) { m_cmsObject = cms; m_resource = base.m_resource; m_cache = base.m_cache; m_req = base.m_req; m_res = base.m_res; m_streaming = base.m_streaming; m_top = base.m_top; m_flexRequestList = base.m_flexRequestList; m_flexResponseList = base.m_flexResponseList; m_flexContextInfoList = base.m_flexContextInfoList; m_forwardMode = base.m_forwardMode; m_throwableResourceUri = base.m_throwableResourceUri; } /** * Default constructor.<p> * * @param cms the initial CmsObject to wrap in the controller * @param resource the file requested * @param cache the instance of the flex cache * @param req the current request * @param res the current response * @param streaming indicates if the response is streaming * @param top indicates if the response is the top response */ public CmsFlexController(CmsObject cms, CmsResource resource, CmsFlexCache cache, HttpServletRequest req, HttpServletResponse res, boolean streaming, boolean top) { m_cmsObject = cms; m_resource = resource; m_cache = cache; m_req = req; m_res = res; m_streaming = streaming; m_top = top; m_flexRequestList = new Vector<CmsFlexRequest>(); m_flexResponseList = new Vector<CmsFlexResponse>(); m_flexContextInfoList = new Vector<CmsFlexRequestContextInfo>(); m_forwardMode = false; m_throwableResourceUri = null; } /** * Returns the wrapped CmsObject form the provided request, or <code>null</code> if the * request is not running inside OpenCms.<p> * * @param req the current request * @return the wrapped CmsObject */ public static CmsObject getCmsObject(ServletRequest req) { CmsFlexController controller = (CmsFlexController) req.getAttribute(ATTRIBUTE_NAME); if (controller != null) { return controller.getCmsObject(); } else { return null; } } /** * Returns the controller from the given request, or <code>null</code> if the * request is not running inside OpenCms.<p> * * @param req the request to get the controller from * * @return the controller from the given request, or <code>null</code> if the request is not running inside OpenCms */ public static CmsFlexController getController(ServletRequest req) { return (CmsFlexController) req.getAttribute(ATTRIBUTE_NAME); } /** * Provides access to a root cause Exception that might have occurred in a complex include scenario.<p> * * @param req the current request * * @return the root cause exception or null if no root cause exception is available * * @see #getThrowable() */ public static Throwable getThrowable(ServletRequest req) { CmsFlexController controller = (CmsFlexController) req.getAttribute(ATTRIBUTE_NAME); if (controller != null) { return controller.getThrowable(); } else { return null; } } /** * Provides access to URI of a VFS resource that caused an exception that might have occurred in a complex include scenario.<p> * * @param req the current request * * @return to URI of a VFS resource that caused an exception, or <code>null</code> * * @see #getThrowableResourceUri() */ public static String getThrowableResourceUri(ServletRequest req) { CmsFlexController controller = (CmsFlexController) req.getAttribute(ATTRIBUTE_NAME); if (controller != null) { return controller.getThrowableResourceUri(); } else { return null; } } /** * Checks if the provided request is running in OpenCms and the current users project is the online project.<p> * * @param req the current request * * @return <code>true</code> if the request is running in OpenCms and the current users project is * the online project, <code>false</code> otherwise */ public static boolean isCmsOnlineRequest(ServletRequest req) { if (req == null) { return false; } return getController(req).getCmsObject().getRequestContext().getCurrentProject().isOnlineProject(); } /** * Checks if the provided request is running in OpenCms.<p> * * @param req the current request * * @return <code>true</code> if the request is running in OpenCms, <code>false</code> otherwise */ public static boolean isCmsRequest(ServletRequest req) { return ((req != null) && (req.getAttribute(ATTRIBUTE_NAME) != null)); } /** * Checks if the request has the "If-Modified-Since" header set, and if so, * if the header date value is equal to the provided last modification date.<p> * * @param req the request to set the "If-Modified-Since" date header from * @param dateLastModified the date to compare the header with * * @return <code>true</code> if the header is set and the header date is equal to the provided date */ public static boolean isNotModifiedSince(HttpServletRequest req, long dateLastModified) { // check if the request contains a last modified header try { long lastModifiedHeader = req.getDateHeader(CmsRequestUtil.HEADER_IF_MODIFIED_SINCE); // if last modified header is set (> -1), compare it to the requested resource return ((lastModifiedHeader > -1) && (((dateLastModified / 1000) * 1000) == lastModifiedHeader)); } catch (Exception ex) { // some clients (e.g. User-Agent: BlackBerry7290/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/111) // send an invalid "If-Modified-Since" header (e.g. in german locale) // which breaks with http://www.w3.org/Protocols/rfc2616/rfc2616-sec3.html // this has to be caught because the subsequent request for the 500 error handler // would run into the same exception. LOG.warn(Messages.get().getBundle().key(Messages.ERR_HEADER_IFMODIFIEDSINCE_FORMAT_3, new Object[] { CmsRequestUtil.HEADER_IF_MODIFIED_SINCE, req.getHeader(CmsRequestUtil.HEADER_USER_AGENT), req.getHeader(CmsRequestUtil.HEADER_IF_MODIFIED_SINCE) })); } return false; } /** * Removes the controller attribute from a request.<p> * * @param req the request to remove the controller from */ public static void removeController(ServletRequest req) { CmsFlexController controller = (CmsFlexController) req.getAttribute(ATTRIBUTE_NAME); if (controller != null) { controller.clear(); } } /** * Stores the given controller in the given request (using a request attribute).<p> * * @param req the request where to store the controller in * @param controller the controller to store */ public static void setController(ServletRequest req, CmsFlexController controller) { req.setAttribute(CmsFlexController.ATTRIBUTE_NAME, controller); } /** * Sets the <code>Expires</code> date header for a given http request.<p> * * Also sets the <code>cache-control: max-age</code> header to the time of the expiration. * A certain upper limit is imposed on the expiration date parameter to ensure the resources are * not cached to long in proxies. This can be controlled by the <code>maxAge</code> parameter. * If <code>maxAge</code> is lower then 0, then a default max age of 86400000 msec (1 day) is used.<p> * * @param res the response to set the "Expires" date header for * @param maxAge maximum amount of time in milliseconds the response remains valid * @param dateExpires the date to set (if this is not in the future, it is ignored) */ public static void setDateExpiresHeader(HttpServletResponse res, long dateExpires, long maxAge) { long now = System.currentTimeMillis(); if ((dateExpires > now) && (dateExpires != CmsResource.DATE_EXPIRED_DEFAULT)) { // important: many caches (browsers or proxy) use the "Expires" header // to avoid re-loading of pages that are not expired // while this is right in general, no changes before the expiration date // will be displayed // therefore it is better to not use an expiration to far in the future // if no valid max age is set, restrict it to 24 hrs if (maxAge < 0L) { maxAge = 86400000; } if ((dateExpires - now) > maxAge) { // set "Expires" header max one day into the future dateExpires = now + maxAge; } res.setDateHeader(CmsRequestUtil.HEADER_EXPIRES, dateExpires); // setting the "Expires" header only is not sufficient - even expired documents seems to be cached // therefore, the "cache-control: max-age" is also set res.setHeader(CmsRequestUtil.HEADER_CACHE_CONTROL, CmsRequestUtil.HEADER_VALUE_MAX_AGE + (maxAge / 1000L)); } } /** * Sets the "last modified" date header for a given http request.<p> * * @param res the response to set the "last modified" date header for * @param dateLastModified the date to set (if this is lower then 0, the current time is set) */ public static void setDateLastModifiedHeader(HttpServletResponse res, long dateLastModified) { if (dateLastModified > -1) { // set date last modified header (precision is only second, not millisecond res.setDateHeader(CmsRequestUtil.HEADER_LAST_MODIFIED, (dateLastModified / 1000) * 1000); } else { // this resource can not be optimized for "last modified", use current time as header res.setDateHeader(CmsRequestUtil.HEADER_LAST_MODIFIED, System.currentTimeMillis()); } } /** * Clears all data of this controller.<p> */ public void clear() { if (m_flexRequestList != null) { m_flexRequestList.clear(); } m_flexRequestList = null; if (m_flexResponseList != null) { m_flexResponseList.clear(); } m_flexResponseList = null; if (m_req != null) { m_req.removeAttribute(ATTRIBUTE_NAME); } m_req = null; m_res = null; m_cmsObject = null; m_resource = null; m_cache = null; m_throwable = null; } /** * Returns the CmsFlexCache instance where all results from this request will be cached in.<p> * * This is public so that pages like the Flex Cache Administration page * have a way to access the cache object.<p> * * @return the CmsFlexCache instance where all results from this request will be cached in */ public CmsFlexCache getCmsCache() { return m_cache; } /** * Returns the wrapped CmsObject.<p> * * @return the wrapped CmsObject */ public CmsObject getCmsObject() { return m_cmsObject; } /** * This method provides access to the top-level CmsResource of the request * which is of a type that supports the FlexCache, * i.e. usually the CmsFile that is identical to the file uri requested by the user, * not he current included element.<p> * * @return the requested top-level CmsFile */ public CmsResource getCmsResource() { return m_resource; } /** * Returns the current flex request.<p> * * @return the current flex request */ public CmsFlexRequest getCurrentRequest() { return m_flexRequestList.get(m_flexRequestList.size() - 1); } /** * Returns the current flex response.<p> * * @return the current flex response */ public CmsFlexResponse getCurrentResponse() { return m_flexResponseList.get(m_flexResponseList.size() - 1); } /** * Returns the combined "expires" date for all resources read during this request.<p> * * @return the combined "expires" date for all resources read during this request */ public long getDateExpires() { int pos = m_flexContextInfoList.size() - 1; if (pos < 0) { // ensure a valid position is used return CmsResource.DATE_EXPIRED_DEFAULT; } return (m_flexContextInfoList.get(pos)).getDateExpires(); } /** * Returns the combined "last modified" date for all resources read during this request.<p> * * @return the combined "last modified" date for all resources read during this request */ public long getDateLastModified() { int pos = m_flexContextInfoList.size() - 1; if (pos < 0) { // ensure a valid position is used return CmsResource.DATE_RELEASED_DEFAULT; } return (m_flexContextInfoList.get(pos)).getDateLastModified(); } /** * Returns the size of the response stack.<p> * * @return the size of the response stack */ public int getResponseStackSize() { return m_flexResponseList.size(); } /** * Returns an exception (Throwable) that was caught during inclusion of sub elements, * or null if no exceptions where thrown in sub elements.<p> * * @return an exception (Throwable) that was caught during inclusion of sub elements */ public Throwable getThrowable() { return m_throwable; } /** * Returns the URI of a VFS resource that caused the exception that was caught during inclusion of sub elements, * might return null if no URI information was available for the exception.<p> * * @return the URI of a VFS resource that caused the exception that was caught during inclusion of sub elements */ public String getThrowableResourceUri() { return m_throwableResourceUri; } /** * Returns the current http request.<p> * * @return the current http request */ public HttpServletRequest getTopRequest() { return m_req; } /** * Returns the current http response.<p> * * @return the current http response */ public HttpServletResponse getTopResponse() { return m_res; } /** * Returns <code>true</code> if the controller does not yet contain any requests.<p> * * @return <code>true</code> if the controller does not yet contain any requests */ public boolean isEmptyRequestList() { return (m_flexRequestList != null) && m_flexRequestList.isEmpty(); } /** * Returns <code>true</code> if this controller is currently in "forward" mode.<p> * * @return <code>true</code> if this controller is currently in "forward" mode */ public boolean isForwardMode() { return m_forwardMode; } /** * Returns <code>true</code> if the generated output of the response should * be written to the stream directly.<p> * * @return <code>true</code> if the generated output of the response should be written to the stream directly */ public boolean isStreaming() { return m_streaming; } /** * Returns <code>true</code> if this controller was generated as top level controller.<p> * * If a resource (e.g. a JSP) is processed and it's content is included in * another resource, then this will be <code>false</code>. * * @return <code>true</code> if this controller was generated as top level controller * * @see org.opencms.loader.I_CmsResourceLoader#dump(CmsObject, CmsResource, String, java.util.Locale, HttpServletRequest, HttpServletResponse) * @see org.opencms.jsp.CmsJspActionElement#getContent(String) */ public boolean isTop() { return m_top; } /** * Removes the topmost request/response pair from the stack.<p> */ public void pop() { if ((m_flexRequestList != null) && !m_flexRequestList.isEmpty()) { m_flexRequestList.remove(m_flexRequestList.size() - 1); } if ((m_flexResponseList != null) && !m_flexRequestList.isEmpty()) { m_flexResponseList.remove(m_flexResponseList.size() - 1); } if ((m_flexContextInfoList != null) && !m_flexContextInfoList.isEmpty()) { CmsFlexRequestContextInfo info = m_flexContextInfoList.remove(m_flexContextInfoList.size() - 1); if (m_flexContextInfoList.size() > 0) { (m_flexContextInfoList.get(0)).merge(info); updateRequestContextInfo(); } } } /** * Adds another flex request/response pair to the stack.<p> * * @param req the request to add * @param res the response to add */ public void push(CmsFlexRequest req, CmsFlexResponse res) { m_flexRequestList.add(req); m_flexResponseList.add(res); m_flexContextInfoList.add(new CmsFlexRequestContextInfo()); updateRequestContextInfo(); } /** * Sets the value of the "forward mode" flag.<p> * * @param value the forward mode to set */ public void setForwardMode(boolean value) { m_forwardMode = value; } /** * Sets an exception (Throwable) that was caught during inclusion of sub elements.<p> * * If another exception is already set in this controller, then the additional exception * is ignored.<p> * * @param throwable the exception (Throwable) to set * @param resource the URI of the VFS resource the error occurred on (might be <code>null</code> if unknown) * * @return the exception stored in the controller */ public Throwable setThrowable(Throwable throwable, String resource) { if (m_throwable == null) { m_throwable = throwable; m_throwableResourceUri = resource; } else { if (LOG.isDebugEnabled()) { if (resource != null) { LOG.debug(Messages.get().getBundle().key(Messages.LOG_FLEXCONTROLLER_IGNORED_EXCEPTION_1, resource)); } else { LOG.debug(Messages.get().getBundle().key(Messages.LOG_FLEXCONTROLLER_IGNORED_EXCEPTION_0)); } } } return m_throwable; } /** * Puts the response in a suspended state.<p> */ public void suspendFlexResponse() { for (int i = 0; i < m_flexResponseList.size(); i++) { CmsFlexResponse res = m_flexResponseList.get(i); res.setSuspended(true); } } /** * Updates the "last modified" date and the "expires" date * for all resources read during this request with the given values.<p> * * The currently stored value for "last modified" is only updated with the new value if * the new value is either larger (i.e. newer) then the stored value, * or if the new value is less then zero, which indicates that the "last modified" * optimization can not be used because the element is dynamic.<p> * * The stored "expires" value is only updated if the new value is smaller * then the stored value.<p> * * @param dateLastModified the value to update the "last modified" date with * @param dateExpires the value to update the "expires" date with */ public void updateDates(long dateLastModified, long dateExpires) { int pos = m_flexContextInfoList.size() - 1; if (pos < 0) { // ensure a valid position is used return; } (m_flexContextInfoList.get(pos)).updateDates(dateLastModified, dateExpires); } /** * Updates the context info of the request context.<p> */ private void updateRequestContextInfo() { if ((m_flexContextInfoList != null) && !m_flexContextInfoList.isEmpty()) { m_cmsObject.getRequestContext().setAttribute(CmsRequestUtil.HEADER_LAST_MODIFIED, m_flexContextInfoList.get(m_flexContextInfoList.size() - 1)); } } }