Java tutorial
/* * Copyright 2006-2007 Open Source Applications Foundation * * Licensed 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 * * 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.osaf.cosmo.dav.caldav.report; import java.io.ByteArrayInputStream; import java.io.StringWriter; import java.text.ParseException; import java.util.ArrayList; import net.fortuna.ical4j.data.CalendarOutputter; import net.fortuna.ical4j.model.Calendar; import net.fortuna.ical4j.model.DateTime; import net.fortuna.ical4j.model.Period; import net.fortuna.ical4j.model.component.VFreeBusy; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.jackrabbit.webdav.version.report.ReportInfo; import org.apache.jackrabbit.webdav.version.report.ReportType; import org.apache.jackrabbit.webdav.xml.DomUtil; import org.osaf.cosmo.calendar.FreeBusyUtils; import org.osaf.cosmo.calendar.ICalendarUtils; import org.osaf.cosmo.dav.BadRequestException; import org.osaf.cosmo.dav.DavCollection; import org.osaf.cosmo.dav.DavException; import org.osaf.cosmo.dav.DavResource; import org.osaf.cosmo.dav.ForbiddenException; import org.osaf.cosmo.dav.UnprocessableEntityException; import org.osaf.cosmo.dav.caldav.CaldavConstants; import org.osaf.cosmo.dav.impl.DavCalendarCollection; import org.osaf.cosmo.dav.impl.DavCalendarResource; import org.osaf.cosmo.dav.impl.DavItemCollection; import org.osaf.cosmo.dav.report.SimpleReport; import org.w3c.dom.Element; /** * <p> * Represents the <code>CALDAV:free-busy-query</code> report that * provides a mechanism for finding free-busy information. * </p> */ public class FreeBusyReport extends SimpleReport implements CaldavConstants { private static final Log log = LogFactory.getLog(FreeBusyReport.class); private Period freeBusyRange; private ArrayList<VFreeBusy> freeBusyResults; public static final ReportType REPORT_TYPE_CALDAV_FREEBUSY = ReportType .register(ELEMENT_CALDAV_CALENDAR_FREEBUSY, NAMESPACE_CALDAV, FreeBusyReport.class); // Report methods public ReportType getType() { return REPORT_TYPE_CALDAV_FREEBUSY; } // ReportBase methods /** * Parses the report info, extracting the time range. */ protected void parseReport(ReportInfo info) throws DavException { if (!getType().isRequestedReportType(info)) throw new DavException("Report not of type " + getType()); freeBusyRange = findFreeBusyRange(info); } /** * <p> * Runs the report query and generates a resulting <code>VFREEBUSY</code>. * </p> * <p> * The set of <code>VFREEBUSY</code> components that are returned by the * query are merged into a single component. It is wrapped in a calendar * object and converted using UTF-8 to bytes which are set as the report * stream. The report's content type and encoding are also set. * </p> * * @throws UnprocessableEntityException if the targeted resource is not a * collection and is not a calendar resource. * @throws ForbiddenException if the targeted resource or an ancestor * collection is excluded from free-busy rollups */ protected void runQuery() throws DavException { if (!(getResource().isCollection() || getResource() instanceof DavCalendarResource)) throw new UnprocessableEntityException(getType() + " report not supported for non-calendar resources"); // if the resource or any of its ancestors is excluded from // free busy rollups, deny the query DavItemCollection dc = getResource().isCollection() ? (DavItemCollection) getResource() : (DavItemCollection) getResource().getParent(); while (dc != null) { if (dc.isExcludedFromFreeBusyRollups()) throw new ForbiddenException( "Targeted resource or ancestor collection does not participate in freebusy rollups"); dc = (DavItemCollection) dc.getParent(); if (!dc.exists()) dc = null; } freeBusyResults = new ArrayList<VFreeBusy>(); super.runQuery(); VFreeBusy vfb = FreeBusyUtils.mergeComponents(freeBusyResults, freeBusyRange); Calendar calendar = ICalendarUtils.createBaseCalendar(vfb); String output = writeCalendar(calendar); setContentType("text/calendar"); setEncoding("UTF-8"); try { setStream(new ByteArrayInputStream(output.getBytes("UTF-8"))); } catch (Exception e) { throw new DavException(e); } } protected void doQuerySelf(DavResource resource) throws DavException { if (!resource.isCollection()) { if (isExcluded(resource.getParent())) return; // runQuery() has already determined that this is a calendar // resource DavCalendarResource dcr = (DavCalendarResource) resource; VFreeBusy vfb = dcr.generateFreeBusy(freeBusyRange); if (vfb != null) freeBusyResults.add(vfb); return; } // collections themselves never match - only calendar resources } protected void doQueryChildren(DavCollection collection) throws DavException { if (isExcluded(collection)) return; if (collection instanceof DavCalendarCollection) { DavCalendarCollection dcc = (DavCalendarCollection) collection; VFreeBusy vfb = dcc.generateFreeBusy(freeBusyRange); if (vfb != null) freeBusyResults.add(vfb); return; } // if it's a regular collection, there won't be any calendar resources // within it to match the query } protected void doQueryDescendents(DavCollection collection) throws DavException { if (isExcluded(collection)) return; super.doQueryDescendents(collection); } // our methods private static Period findFreeBusyRange(ReportInfo info) throws DavException { Element tre = info.getContentElement(ELEMENT_CALDAV_TIME_RANGE, NAMESPACE_CALDAV); if (tre == null) throw new BadRequestException("Expected " + QN_CALDAV_TIME_RANGE); DateTime sdt = null; try { String start = DomUtil.getAttribute(tre, ATTR_CALDAV_START, null); sdt = new DateTime(start); } catch (ParseException e) { throw new BadRequestException("Attribute " + ATTR_CALDAV_START + " not parseable: " + e.getMessage()); } DateTime edt = null; try { String end = DomUtil.getAttribute(tre, ATTR_CALDAV_END, null); edt = new DateTime(end); } catch (ParseException e) { throw new BadRequestException("Attribute " + ATTR_CALDAV_END + " not parseable: " + e.getMessage()); } return new Period(sdt, edt); } private static boolean isExcluded(DavCollection collection) { DavItemCollection dic = (DavItemCollection) collection; return dic.isExcludedFromFreeBusyRollups(); } private VFreeBusy mergeFreeBusyResults() { // If there is only one result, return it if (freeBusyResults.size() == 1) return freeBusyResults.get(0); // Otherwise, merge results into single VFREEBUSY return FreeBusyUtils.mergeComponents(freeBusyResults, freeBusyRange); } private static String writeCalendar(Calendar calendar) throws DavException { try { StringWriter out = new StringWriter(); CalendarOutputter outputter = new CalendarOutputter(); outputter.output(calendar, out); String output = out.toString(); out.close(); // NB ical4j's outputter generates \r\n line ends but we // need only \n, so remove all \r's from the string output = output.replaceAll("\r", ""); return output; } catch (Exception e) { throw new DavException(e); } } }