001 package biweekly.io.json;
002
003 import static biweekly.util.IOUtils.utf8Reader;
004 import static biweekly.util.StringUtils.NEWLINE;
005
006 import java.io.Closeable;
007 import java.io.File;
008 import java.io.FileNotFoundException;
009 import java.io.IOException;
010 import java.io.InputStream;
011 import java.io.Reader;
012 import java.io.StringReader;
013 import java.util.ArrayList;
014 import java.util.Arrays;
015 import java.util.HashMap;
016 import java.util.List;
017 import java.util.Map;
018
019 import biweekly.ICalDataType;
020 import biweekly.ICalendar;
021 import biweekly.component.ICalComponent;
022 import biweekly.component.marshaller.ICalComponentMarshaller;
023 import biweekly.component.marshaller.ICalendarMarshaller;
024 import biweekly.io.CannotParseException;
025 import biweekly.io.ICalMarshallerRegistrar;
026 import biweekly.io.SkipMeException;
027 import biweekly.io.json.JCalRawReader.JCalDataStreamListener;
028 import biweekly.parameter.ICalParameters;
029 import biweekly.property.ICalProperty;
030 import biweekly.property.RawProperty;
031 import biweekly.property.marshaller.ICalPropertyMarshaller;
032 import biweekly.property.marshaller.ICalPropertyMarshaller.Result;
033 import biweekly.property.marshaller.RawPropertyMarshaller;
034
035 import com.fasterxml.jackson.core.JsonParseException;
036
037 /*
038 Copyright (c) 2013, Michael Angstadt
039 All rights reserved.
040
041 Redistribution and use in source and binary forms, with or without
042 modification, are permitted provided that the following conditions are met:
043
044 1. Redistributions of source code must retain the above copyright notice, this
045 list of conditions and the following disclaimer.
046 2. Redistributions in binary form must reproduce the above copyright notice,
047 this list of conditions and the following disclaimer in the documentation
048 and/or other materials provided with the distribution.
049
050 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
051 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
052 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
053 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
054 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
055 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
056 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
057 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
058 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
059 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
060 */
061
062 /**
063 * <p>
064 * Parses {@link ICalendar} objects from a jCal data stream (JSON).
065 * </p>
066 * <p>
067 * <b>Example:</b>
068 *
069 * <pre class="brush:java">
070 * InputStream in = ...
071 * JCalReader jcalReader = new JCalReader(in);
072 * ICalendar ical;
073 * while ((ical = jcalReader.readNext()) != null){
074 * ...
075 * }
076 * jcalReader.close();
077 * </pre>
078 *
079 * </p>
080 * @author Michael Angstadt
081 * @see <a href="http://tools.ietf.org/html/draft-ietf-jcardcal-jcal-05">jCal
082 * draft</a>
083 */
084 public class JCalReader implements Closeable {
085 private static final ICalendarMarshaller icalMarshaller = ICalMarshallerRegistrar.getICalendarMarshaller();
086 private ICalMarshallerRegistrar registrar = new ICalMarshallerRegistrar();
087 private final JCalRawReader reader;
088 private final List<String> warnings = new ArrayList<String>();
089
090 /**
091 * Creates a jCard reader.
092 * @param json the JSON string
093 */
094 public JCalReader(String json) {
095 this(new StringReader(json));
096 }
097
098 /**
099 * Creates a jCard reader.
100 * @param in the input stream to read the vCards from
101 */
102 public JCalReader(InputStream in) {
103 this(utf8Reader(in));
104 }
105
106 /**
107 * Creates a jCard reader.
108 * @param file the file to read the vCards from
109 * @throws FileNotFoundException if the file doesn't exist
110 */
111 public JCalReader(File file) throws FileNotFoundException {
112 this(utf8Reader(file));
113 }
114
115 /**
116 * Creates a jCard reader.
117 * @param reader the reader to read the vCards from
118 */
119 public JCalReader(Reader reader) {
120 this.reader = new JCalRawReader(reader);
121 }
122
123 /**
124 * Gets the warnings from the last iCalendar object that was unmarshalled.
125 * This list is reset every time a new iCalendar object is read.
126 * @return the warnings or empty list if there were no warnings
127 */
128 public List<String> getWarnings() {
129 return new ArrayList<String>(warnings);
130 }
131
132 /**
133 * <p>
134 * Registers an experimental property marshaller. Can also be used to
135 * override the marshaller of a standard property (such as DTSTART). Calling
136 * this method is the same as calling:
137 * </p>
138 * <p>
139 * {@code getRegistrar().register(marshaller)}.
140 * </p>
141 * @param marshaller the marshaller to register
142 */
143 public void registerMarshaller(ICalPropertyMarshaller<? extends ICalProperty> marshaller) {
144 registrar.register(marshaller);
145 }
146
147 /**
148 * <p>
149 * Registers an experimental component marshaller. Can also be used to
150 * override the marshaller of a standard component (such as VEVENT). Calling
151 * this method is the same as calling:
152 * </p>
153 * <p>
154 * {@code getRegistrar().register(marshaller)}.
155 * </p>
156 * @param marshaller the marshaller to register
157 */
158 public void registerMarshaller(ICalComponentMarshaller<? extends ICalComponent> marshaller) {
159 registrar.register(marshaller);
160 }
161
162 /**
163 * Gets the object that manages the component/property marshaller objects.
164 * @return the marshaller registrar
165 */
166 public ICalMarshallerRegistrar getRegistrar() {
167 return registrar;
168 }
169
170 /**
171 * Sets the object that manages the component/property marshaller objects.
172 * @param registrar the marshaller registrar
173 */
174 public void setRegistrar(ICalMarshallerRegistrar registrar) {
175 this.registrar = registrar;
176 }
177
178 /**
179 * Reads the next iCalendar object from the JSON data stream.
180 * @return the iCalendar object or null if there are no more
181 * @throws JCalParseException if the jCal syntax is incorrect (the JSON
182 * syntax may be valid, but it is not in the correct jCal format).
183 * @throws JsonParseException if the JSON syntax is incorrect
184 * @throws IOException if there is a problem reading from the data stream
185 */
186 public ICalendar readNext() throws IOException {
187 if (reader.eof()) {
188 return null;
189 }
190
191 warnings.clear();
192
193 JCalDataStreamListenerImpl listener = new JCalDataStreamListenerImpl();
194 reader.readNext(listener);
195 return listener.getICalendar();
196 }
197
198 private void addWarning(String message, String propertyName) {
199 StringBuilder sb = new StringBuilder();
200 sb.append("Line ").append(reader.getLineNum());
201 if (propertyName != null) {
202 sb.append(" (").append(propertyName).append(" property)");
203 }
204 sb.append(": ").append(message);
205
206 warnings.add(sb.toString());
207 }
208
209 //@Override
210 public void close() throws IOException {
211 reader.close();
212 }
213
214 private class JCalDataStreamListenerImpl implements JCalDataStreamListener {
215 private final Map<List<String>, ICalComponent> components = new HashMap<List<String>, ICalComponent>();
216
217 public void readProperty(List<String> componentHierarchy, String propertyName, ICalParameters parameters, ICalDataType dataType, JCalValue value) {
218 //get the component that the property belongs to
219 ICalComponent parent = components.get(componentHierarchy);
220
221 //unmarshal the property
222 ICalPropertyMarshaller<? extends ICalProperty> m = registrar.getPropertyMarshaller(propertyName);
223 ICalProperty property = null;
224 try {
225 Result<? extends ICalProperty> result = m.parseJson(value, dataType, parameters);
226
227 for (String warning : result.getWarnings()) {
228 addWarning(warning, propertyName);
229 }
230
231 property = result.getProperty();
232 } catch (SkipMeException e) {
233 if (e.getMessage() == null) {
234 addWarning("Property has requested that it be skipped.", propertyName);
235 } else {
236 addWarning("Property has requested that it be skipped: " + e.getMessage(), propertyName);
237 }
238 } catch (CannotParseException e) {
239 Result<? extends ICalProperty> result = new RawPropertyMarshaller(propertyName).parseJson(value, dataType, parameters);
240 for (String warning : result.getWarnings()) {
241 addWarning(warning, propertyName);
242 }
243 property = result.getProperty();
244
245 String valueStr = ((RawProperty) property).getValue();
246 if (e.getMessage() == null) {
247 addWarning("Property value could not be unmarshalled: " + valueStr, propertyName);
248 } else {
249 addWarning("Property value could not be unmarshalled." + NEWLINE + " Value: " + valueStr + NEWLINE + " Reason: " + e.getMessage(), propertyName);
250 }
251 }
252
253 if (property != null) {
254 parent.addProperty(property);
255 }
256 }
257
258 public void readComponent(List<String> parentHierarchy, String componentName) {
259 ICalComponentMarshaller<? extends ICalComponent> m = registrar.getComponentMarshaller(componentName);
260 ICalComponent component = m.emptyInstance();
261
262 ICalComponent parent = components.get(parentHierarchy);
263 if (parent != null) {
264 parent.addComponent(component);
265 }
266
267 List<String> hierarchy = new ArrayList<String>(parentHierarchy);
268 hierarchy.add(componentName);
269 components.put(hierarchy, component);
270 }
271
272 public ICalendar getICalendar() {
273 if (components.isEmpty()) {
274 //EOF
275 return null;
276 }
277
278 ICalComponent component = components.get(Arrays.asList(icalMarshaller.getComponentName().toLowerCase()));
279 if (component == null) {
280 //should never happen because the parser always looks for a "vcalendar" component
281 return null;
282 }
283
284 if (component instanceof ICalendar) {
285 //should happen every time
286 return (ICalendar) component;
287 }
288
289 //this will only happen if the user decides to override the ICalendarMarshaller for some reason
290 ICalendar ical = icalMarshaller.emptyInstance();
291 ical.addComponent(component);
292 return ical;
293 }
294 }
295 }