1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/net/fortuna/ical4j/util/Calendars.java Tue Feb 10 18:12:00 2015 +0100
1.3 @@ -0,0 +1,231 @@
1.4 +/**
1.5 + * Copyright (c) 2012, Ben Fortuna
1.6 + * All rights reserved.
1.7 + *
1.8 + * Redistribution and use in source and binary forms, with or without
1.9 + * modification, are permitted provided that the following conditions
1.10 + * are met:
1.11 + *
1.12 + * o Redistributions of source code must retain the above copyright
1.13 + * notice, this list of conditions and the following disclaimer.
1.14 + *
1.15 + * o Redistributions in binary form must reproduce the above copyright
1.16 + * notice, this list of conditions and the following disclaimer in the
1.17 + * documentation and/or other materials provided with the distribution.
1.18 + *
1.19 + * o Neither the name of Ben Fortuna nor the names of any other contributors
1.20 + * may be used to endorse or promote products derived from this software
1.21 + * without specific prior written permission.
1.22 + *
1.23 + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
1.24 + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
1.25 + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
1.26 + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
1.27 + * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
1.28 + * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
1.29 + * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
1.30 + * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
1.31 + * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
1.32 + * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
1.33 + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.34 + */
1.35 +package net.fortuna.ical4j.util;
1.36 +
1.37 +import java.io.FileInputStream;
1.38 +import java.io.IOException;
1.39 +import java.net.URL;
1.40 +import java.nio.charset.Charset;
1.41 +import java.util.HashMap;
1.42 +import java.util.Iterator;
1.43 +import java.util.Map;
1.44 +
1.45 +import net.fortuna.ical4j.data.CalendarBuilder;
1.46 +import net.fortuna.ical4j.data.ParserException;
1.47 +import net.fortuna.ical4j.model.Calendar;
1.48 +import net.fortuna.ical4j.model.Component;
1.49 +import net.fortuna.ical4j.model.ComponentList;
1.50 +import net.fortuna.ical4j.model.ConstraintViolationException;
1.51 +import net.fortuna.ical4j.model.IndexedComponentList;
1.52 +import net.fortuna.ical4j.model.Parameter;
1.53 +import net.fortuna.ical4j.model.Property;
1.54 +import net.fortuna.ical4j.model.component.VTimeZone;
1.55 +import net.fortuna.ical4j.model.parameter.TzId;
1.56 +import net.fortuna.ical4j.model.property.Method;
1.57 +import net.fortuna.ical4j.model.property.Uid;
1.58 +
1.59 +/**
1.60 + * $Id$
1.61 + *
1.62 + * Created on 10/11/2006
1.63 + *
1.64 + * Utility method for working with {@link Calendar}s.
1.65 + * @author Ben Fortuna
1.66 + */
1.67 +public final class Calendars {
1.68 +
1.69 + /**
1.70 + * Constructor made private to enforce static nature.
1.71 + */
1.72 + private Calendars() {
1.73 + }
1.74 +
1.75 + /**
1.76 + * Loads a calendar from the specified file.
1.77 + * @param filename the name of the file from which to load calendar data
1.78 + * @return returns a new calendar instance initialised from the specified file
1.79 + * @throws IOException occurs when there is an error reading the specified file
1.80 + * @throws ParserException occurs when the data in the specified file is invalid
1.81 + */
1.82 + public static Calendar load(final String filename) throws IOException, ParserException {
1.83 + final FileInputStream fin = new FileInputStream(filename);
1.84 + final CalendarBuilder builder = new CalendarBuilder();
1.85 + return builder.build(fin);
1.86 + }
1.87 +
1.88 + /**
1.89 + * Loads a calendar from the specified URL.
1.90 + * @param url the URL from which to load calendar data
1.91 + * @return returns a new calendar instance initialised from the specified URL
1.92 + * @throws IOException occurs when there is an error reading from the specified URL
1.93 + * @throws ParserException occurs when the data in the specified URL is invalid
1.94 + */
1.95 + public static Calendar load(final URL url) throws IOException, ParserException {
1.96 + final CalendarBuilder builder = new CalendarBuilder();
1.97 + return builder.build(url.openStream());
1.98 + }
1.99 +
1.100 + /**
1.101 + * Merge all properties and components from two specified calendars into one instance.
1.102 + * Note that the merge process is not very sophisticated, and may result in invalid calendar
1.103 + * data (e.g. multiple properties of a type that should only be specified once).
1.104 + * @param c1 the first calendar to merge
1.105 + * @param c2 the second calendar to merge
1.106 + * @return a Calendar instance containing all properties and components from both of the specified calendars
1.107 + */
1.108 + public static Calendar merge(final Calendar c1, final Calendar c2) {
1.109 + final Calendar result = new Calendar();
1.110 + result.getProperties().addAll(c1.getProperties());
1.111 + for (final Iterator i = c2.getProperties().iterator(); i.hasNext();) {
1.112 + final Property p = (Property) i.next();
1.113 + if (!result.getProperties().contains(p)) {
1.114 + result.getProperties().add(p);
1.115 + }
1.116 + }
1.117 + result.getComponents().addAll(c1.getComponents());
1.118 + for (final Iterator i = c2.getComponents().iterator(); i.hasNext();) {
1.119 + final Component c = (Component) i.next();
1.120 + if (!result.getComponents().contains(c)) {
1.121 + result.getComponents().add(c);
1.122 + }
1.123 + }
1.124 + return result;
1.125 + }
1.126 +
1.127 + /**
1.128 + * Wraps a component in a calendar.
1.129 + * @param component the component to wrap with a calendar
1.130 + * @return a calendar containing the specified component
1.131 + */
1.132 + public static Calendar wrap(final Component component) {
1.133 + final ComponentList components = new ComponentList();
1.134 + components.add(component);
1.135 + return new Calendar(components);
1.136 + }
1.137 +
1.138 + /**
1.139 + * Splits a calendar object into distinct calendar objects for unique
1.140 + * identifers (UID).
1.141 + * @param calendar a calendar instance
1.142 + * @return an array of calendar objects
1.143 + */
1.144 + public static Calendar[] split(final Calendar calendar) {
1.145 + // if calendar contains one component or less, or is composed entirely of timezone
1.146 + // definitions, return the original calendar unmodified..
1.147 + if (calendar.getComponents().size() <= 1
1.148 + || calendar.getComponents(Component.VTIMEZONE).size() == calendar.getComponents().size()) {
1.149 + return new Calendar[] {calendar};
1.150 + }
1.151 +
1.152 + final IndexedComponentList timezones = new IndexedComponentList(calendar.getComponents(Component.VTIMEZONE),
1.153 + Property.TZID);
1.154 +
1.155 + final Map calendars = new HashMap();
1.156 + for (final Iterator i = calendar.getComponents().iterator(); i.hasNext();) {
1.157 + final Component c = (Component) i.next();
1.158 + if (c instanceof VTimeZone) {
1.159 + continue;
1.160 + }
1.161 +
1.162 + final Uid uid = (Uid) c.getProperty(Property.UID);
1.163 +
1.164 + Calendar uidCal = (Calendar) calendars.get(uid);
1.165 + if (uidCal == null) {
1.166 + uidCal = new Calendar(calendar.getProperties(), new ComponentList());
1.167 + // remove METHOD property for split calendars..
1.168 + for (final Iterator mp = uidCal.getProperties(Property.METHOD).iterator(); mp.hasNext();) {
1.169 + uidCal.getProperties().remove(mp.next());
1.170 + }
1.171 + calendars.put(uid, uidCal);
1.172 + }
1.173 +
1.174 + for (final Iterator j = c.getProperties().iterator(); j.hasNext();) {
1.175 + final Property p = (Property) j.next();
1.176 + final TzId tzid = (TzId) p.getParameter(Parameter.TZID);
1.177 + if (tzid != null) {
1.178 + final VTimeZone timezone = (VTimeZone) timezones.getComponent(tzid.getValue());
1.179 + if (!uidCal.getComponents().contains(timezone)) {
1.180 + uidCal.getComponents().add(timezone);
1.181 + }
1.182 + }
1.183 + }
1.184 + uidCal.getComponents().add(c);
1.185 + }
1.186 + return (Calendar[]) calendars.values().toArray(new Calendar[calendars.values().size()]);
1.187 + }
1.188 +
1.189 + /**
1.190 + * Returns a unique identifier as specified by components in the provided calendar.
1.191 + * @param calendar a calendar instance
1.192 + * @return the UID property
1.193 + * @throws ConstraintViolationException if zero or more than one unique identifer is found in the specified calendar
1.194 + */
1.195 + public static Uid getUid(final Calendar calendar) throws ConstraintViolationException {
1.196 + Uid uid = null;
1.197 + for (final Iterator i = calendar.getComponents().iterator(); i.hasNext();) {
1.198 + final Component c = (Component) i.next();
1.199 + for (final Iterator j = c.getProperties(Property.UID).iterator(); j.hasNext();) {
1.200 + final Uid foundUid = (Uid) j.next();
1.201 + if (uid != null && !uid.equals(foundUid)) {
1.202 + throw new ConstraintViolationException("More than one UID found in calendar");
1.203 + }
1.204 + uid = foundUid;
1.205 + }
1.206 + }
1.207 + if (uid == null) {
1.208 + throw new ConstraintViolationException("Calendar must specify a single unique identifier (UID)");
1.209 + }
1.210 + return uid;
1.211 + }
1.212 +
1.213 + /**
1.214 + * Returns an appropriate MIME Content-Type for the specified calendar object.
1.215 + * @param calendar a calendar instance
1.216 + * @param charset an optional encoding
1.217 + * @return a content type string
1.218 + */
1.219 + public static String getContentType(Calendar calendar, Charset charset) {
1.220 + final StringBuffer b = new StringBuffer("text/calendar");
1.221 +
1.222 + final Method method = (Method) calendar.getProperty(Property.METHOD);
1.223 + if (method != null) {
1.224 + b.append("; method=");
1.225 + b.append(method.getValue());
1.226 + }
1.227 +
1.228 + if (charset != null) {
1.229 + b.append("; charset=");
1.230 + b.append(charset);
1.231 + }
1.232 + return b.toString();
1.233 + }
1.234 +}
