Java tutorial
/** * Licensed to Apereo under one or more contributor license * agreements. See the NOTICE file distributed with this work * for additional information regarding copyright ownership. * Apereo licenses this file to you under the Apache License, * Version 2.0 (the "License"); you may not use this file * except in compliance with the License. You may obtain a * copy of the License at the following location: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. */ package org.jasig.portlet.calendar.adapter; import java.net.URL; import java.util.Collections; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Set; import javax.portlet.PortletRequest; import net.fortuna.ical4j.model.Calendar; import net.fortuna.ical4j.model.Component; import net.fortuna.ical4j.model.Period; import net.fortuna.ical4j.model.PeriodList; import net.fortuna.ical4j.model.Property; import net.fortuna.ical4j.model.PropertyList; import net.fortuna.ical4j.model.component.VEvent; import net.fortuna.ical4j.model.property.DtEnd; import net.fortuna.ical4j.model.property.DtStart; import net.fortuna.ical4j.model.property.Duration; import net.fortuna.ical4j.model.property.RRule; import net.sf.ehcache.Cache; import net.sf.ehcache.Element; import org.apache.commons.httpclient.Credentials; import org.apache.commons.httpclient.auth.AuthScope; import org.apache.commons.httpclient.protocol.Protocol; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.jasig.portlet.calendar.CalendarConfiguration; import org.jasig.portlet.calendar.caching.DefaultCacheKeyGeneratorImpl; import org.jasig.portlet.calendar.caching.ICacheKeyGenerator; import org.jasig.portlet.calendar.credentials.DefaultCredentialsExtractorImpl; import org.jasig.portlet.calendar.credentials.ICredentialsExtractor; import org.jasig.portlet.calendar.url.DefaultUrlCreatorImpl; import org.jasig.portlet.calendar.url.IUrlCreator; import org.joda.time.Interval; import org.osaf.caldav4j.CalDAVCollection; import org.osaf.caldav4j.CalDAVConstants; import org.osaf.caldav4j.exceptions.CalDAV4JException; import org.osaf.caldav4j.methods.CalDAV4JMethodFactory; import org.osaf.caldav4j.methods.HttpClient; import org.osaf.caldav4j.model.request.CalendarQuery; import org.osaf.caldav4j.util.GenerateQuery; import org.osaf.caldav4j.util.UrlUtils; /** * Implementation of {@link ICalendarAdapter} that uses CalDAV * for retrieving ical-based {@link CalendarEventSet}s. * * Useful background articles: * <a href="http://blogs.nologin.es/rickyepoderi/index.php?/archives/14-Introducing-CalDAV-Part-I.html"/> * <a href="http://blogs.nologin.es/rickyepoderi/index.php?/archives/15-Introducing-CalDAV-Part-II.html"/> * * URL format varies per provider (see links above). For Google an URL would be * https://www.google.com/calendar/dav/CALENDERID/events * where CALENDARID is obtained from the properties of the calendars, such as * jameswennmacher@gmail.com for a user's personal calendar, or * en.usa%23holiday%40group.v.calendar.google.com for the US Holidays calendar. * Google uses Basic Authentication (or oAuth 2.0 though this is not implemented yet). * * @author Jen Bourey, jennifer.bourey@gmail.com * @version $Header: CalDavCalendarAdapter.java Exp $ */ public class CalDavCalendarAdapter extends AbstractCalendarAdapter implements ICalendarAdapter { protected final Log log = LogFactory.getLog(this.getClass()); private Cache cache; private IUrlCreator urlCreator = new DefaultUrlCreatorImpl(); private ICredentialsExtractor credentialsExtractor = new DefaultCredentialsExtractorImpl(); private ICacheKeyGenerator cacheKeyGenerator = new DefaultCacheKeyGeneratorImpl(); private String cacheKeyPrefix = "default"; public void setCache(Cache cache) { this.cache = cache; } public void setUrlCreator(IUrlCreator urlCreator) { this.urlCreator = urlCreator; } public void setCredentialsExtractor(ICredentialsExtractor credentialsExtractor) { this.credentialsExtractor = credentialsExtractor; } public void setCacheKeyGenerator(ICacheKeyGenerator cacheKeyGenerator) { this.cacheKeyGenerator = cacheKeyGenerator; } public void setCacheKeyPrefix(String cacheKeyPrefix) { this.cacheKeyPrefix = cacheKeyPrefix; } public CalendarEventSet getEvents(CalendarConfiguration calendarConfiguration, Interval interval, PortletRequest request) throws CalendarException { Set<VEvent> events = new HashSet<VEvent>(); String url = this.urlCreator.constructUrl(calendarConfiguration, interval, request); if (log.isDebugEnabled()) { log.debug("generated url: " + url); } // try to get the cached calendar String key = cacheKeyGenerator.getKey(calendarConfiguration, interval, request, cacheKeyPrefix.concat(".").concat(url)); Element cachedElement = this.cache.get(key); CalendarEventSet eventSet; if (cachedElement == null) { Credentials credentials = credentialsExtractor.getCredentials(request); // retrieve calendars for the current user net.fortuna.ical4j.model.Calendar calendar = retrieveCalendar(url, interval, credentials); // extract events from the calendars events.addAll(convertCalendarToEvents(calendar, interval)); log.debug("contentProcessor found " + events.size() + " events"); // save the calendar event set to the cache eventSet = insertCalendarEventSetIntoCache(this.cache, key, events); } else { eventSet = (CalendarEventSet) cachedElement.getValue(); } return eventSet; } // Have not gotten queries working so this method returns all events in // the calendar. protected final net.fortuna.ical4j.model.Calendar retrieveCalendar(String url, Interval interval, Credentials credentials) { try { // construct a HostConfiguration from the server URL URL hostUrl = new URL(url); int port = hostUrl.getPort(); if (port == -1) { port = hostUrl.getDefaultPort(); } HttpClient httpClient = new HttpClient(); httpClient.getHostConfiguration().setHost(hostUrl.getHost(), port, Protocol.getProtocol(hostUrl.getProtocol())); if (log.isDebugEnabled()) { log.debug("connecting to calDAV host " + httpClient.getHostConfiguration().getHost()); } if (credentials != null) { httpClient.getState().setCredentials(AuthScope.ANY, credentials); httpClient.getParams().setAuthenticationPreemptive(true); } String calendarPath = hostUrl.getPath(); CalDAVCollection calDAVCollection = new CalDAVCollection(calendarPath, httpClient.getHostConfiguration(), new CalDAV4JMethodFactory(), CalDAVConstants.PROC_ID_DEFAULT); // log.debug(calDAVCollection.testConnection(httpClient)); if (log.isDebugEnabled()) { log.debug(calDAVCollection.getCalendarCollectionRoot()); } // Haven't gotten queries working // GenerateQuery gq = new GenerateQuery(); // gq.setTimeRange(new net.fortuna.ical4j.model.Date(interval // .getStart().toDate()), new net.fortuna.ical4j.model.Date( // interval.getEnd().toDate())); // CalendarQuery query = gq.generate(); // Haven't gotten queries working even for single calendar. // Also I don't think Google supports viewing // or querying multiple calendars at once. // List<Calendar> cals = calDAVCollection.queryCalendars(client, query); // return cals.get(0); Calendar cal = calDAVCollection.getCalendar(httpClient, ""); if (log.isDebugEnabled()) { log.debug(cal); } return cal; } catch (CalDAV4JException e) { log.error("CalDAV exception: ", e); throw new CalendarException(e); } catch (Exception e) { log.error(e); throw new CalendarException("Unknown exception while retrieving calendar", e); } } protected final Set<VEvent> convertCalendarToEvents(net.fortuna.ical4j.model.Calendar calendar, Interval interval) throws CalendarException { Period period = new Period(new net.fortuna.ical4j.model.DateTime(interval.getStartMillis()), new net.fortuna.ical4j.model.DateTime(interval.getEndMillis())); Set<VEvent> events = new HashSet<VEvent>(); // if the calendar is null, return empty set if (calendar == null) { log.info("calendar empty, returning empty set"); return Collections.emptySet(); } // retrieve the list of events for this calendar within the // specified time period for (Iterator<Component> i = calendar.getComponents().iterator(); i.hasNext();) { Component component = i.next(); if (component.getName().equals("VEVENT")) { VEvent event = (VEvent) component; if (log.isTraceEnabled()) { log.trace("processing event " + event.getSummary().getValue()); } // calculate the recurrence set for this event // for the specified time period PeriodList periods = event.calculateRecurrenceSet(period); // add each recurrence instance to the event list for (Iterator<Period> iter = periods.iterator(); iter.hasNext();) { Period eventper = iter.next(); PropertyList props = event.getProperties(); // create a new property list, setting the date // information to this event period PropertyList newprops = new PropertyList(); newprops.add(new DtStart(eventper.getStart())); newprops.add(new DtEnd(eventper.getEnd())); for (Iterator<Property> iter2 = props.iterator(); iter2.hasNext();) { Property prop = iter2.next(); // only add non-date-related properties if (!(prop instanceof DtStart) && !(prop instanceof DtEnd) && !(prop instanceof Duration) && !(prop instanceof RRule)) newprops.add(prop); } // create the new event from our property list VEvent newevent = new VEvent(newprops); events.add(newevent); if (log.isTraceEnabled()) { log.trace("added event " + newevent); } } } } return events; } }