/**
* OLAT - Online Learning and Training<br>
* http://www.olat.org
* <p>
* Licensed under the Apache License, Version 2.0 (the "License"); <br>
* you may not use this file except in compliance with the License.<br>
* You may obtain a copy of the License at
* <p>
* http://www.apache.org/licenses/LICENSE-2.0
* <p>
* Unless required by applicable law or agreed to in writing,<br>
* software distributed under the License is distributed on an "AS IS" BASIS, <br>
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. <br>
* See the License for the specific language governing permissions and <br>
* limitations under the License.
* <p>
* Copyright (c) 1999-2006 at Multimedia- & E-Learning Services (MELS),<br>
* University of Zurich, Switzerland.
* <p>
*/
package org.olat.core.dispatcher.mapper;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.olat.core.dispatcher.Dispatcher;
import org.olat.core.dispatcher.DispatcherAction;
import org.olat.core.gui.media.MediaResource;
import org.olat.core.gui.media.NotFoundMediaResource;
import org.olat.core.gui.media.ServletUtil;
import org.olat.core.logging.OLATSecurityException;
import org.olat.core.logging.Tracing;
import org.olat.core.util.UserSession;
import org.olat.core.util.WebappHelper;
/**
* Description:<br>
* Allows to register so called mappers, which map a certain session-unique url
* to a mapper which can dispatch requests to that url.
* <P>
* Initial Date: 10.06.2005 <br>
*
* @author Felix Jost
*/
public class MapperRegistry implements Dispatcher {
private static final String CNAME = MapperRegistry.class.getName();
private static final MediaResource NOTFOUND = new NotFoundMediaResource("not found");
private Map<String, Mapper> map = new HashMap<String, Mapper>();
private int mapid;
/**
*
*/
private MapperRegistry() {
// to avoid browser caching if logging in again using the same browser (css
// cache seems not to be emptied even if browser is closed...)
mapid = ((int) (System.currentTimeMillis() % 1000l)) * 100;
}
/**
* @param us
* @return MapperRegistry
*/
public static MapperRegistry getInstanceFor(UserSession us) {
MapperRegistry mreg;
mreg = (MapperRegistry) us.getEntry(CNAME);
if (mreg == null) {
synchronized (us) {
// need to sync since a browser may request many e.g. pictures in parallel
mreg = (MapperRegistry) us.getEntry(CNAME);
if(mreg == null){
mreg = new MapperRegistry();
us.putEntry(CNAME, mreg);
}
}
}
//}
return mreg;
}
/**
* @param mapper
* @return the path e.g. /olat/m/1001 without / at the end
*/
public String register(Mapper mapper) {
int cur = mapid;
map.put(String.valueOf(cur), mapper);
mapid++; // do not sync instance var inc since mappers of a user will not
// be allocated concurrently (should be done in constructors of
// controllers only / = one gui thread).
return WebappHelper.getServletContextPath() + DispatcherAction.PATH_MAPPED + cur;
}
/**
* @param hreq
* @param hres
*/
public void execute(HttpServletRequest hreq, HttpServletResponse hres, String pathInfo) {
final boolean isDebugLog = Tracing.isDebugEnabled(MapperRegistry.class);
StringBuilder debugMsg = null;
long debug_start = 0;
if (isDebugLog) {
debug_start = System.currentTimeMillis();
debugMsg = new StringBuilder("::mprex:");
}
// e.g. 23423/bla/blu.html
String subInfo = pathInfo.substring(DispatcherAction.PATH_MAPPED.length());
int slashPos = subInfo.indexOf('/');
if (slashPos == -1) {
DispatcherAction.sendNotFound("not found", hres);
return;
}
// e.g. 23423
String smappath = subInfo.substring(0, slashPos);
Mapper m = map.get(smappath);
MediaResource mr;
if (m == null) { // not mapped
mr = NOTFOUND;
} else {
String mod = subInfo.substring(slashPos);
if (mod.indexOf("..") != -1) throw new OLATSecurityException("mapper path contained '..' : " + mod);
// /bla/blu.html
mr = m.handle(mod, hreq);
}
ServletUtil.serveResource(hreq, hres, mr);
if (isDebugLog) {
long afterserved = System.currentTimeMillis();
long syncIntroDiff = afterserved - debug_start;
debugMsg.append("nanoseconds:").append(syncIntroDiff);
Tracing.logDebug(debugMsg.toString(), MapperRegistry.class);
}
}
/**
* remove a registered mapper if it is no longer needed.
*
* @param mapper
*/
public void deregister(Mapper mapper) {
map.values().remove(mapper);
}
}