/**
* Licensed to Jasig under one or more contributor license
* agreements. See the NOTICE file distributed with this work
* for additional information regarding copyright ownership.
* Jasig 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:
*
* 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.portal.character.stream;
import java.util.Collection;
import java.util.Deque;
import java.util.LinkedList;
import java.util.regex.MatchResult;
import javax.servlet.http.HttpServletRequest;
import javax.xml.namespace.QName;
import javax.xml.stream.XMLEventReader;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.events.EndElement;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;
import org.jasig.portal.character.stream.events.CharacterEvent;
/**
* Base implementation of CharacterEventSource that deals with reading the element data off the stream.
*
* @author Eric Dalquist
* @version $Revision$
*/
public abstract class BasePlaceholderEventSource implements CharacterEventSource {
@Override
public void generateCharacterEvents(HttpServletRequest servletRequest, XMLEventReader eventReader,
StartElement event, Collection<CharacterEvent> eventBuffer) throws XMLStreamException {
this.generateCharacterEvents(servletRequest, event, eventBuffer);
this.readToEndElement(eventReader, event);
}
protected void generateCharacterEvents(HttpServletRequest servletRequest, StartElement event, Collection<CharacterEvent> eventBuffer) {
throw new UnsupportedOperationException("Super class must implement this method");
}
@Override
public void generateCharacterEvents(HttpServletRequest servletRequest, MatchResult matchResult,
Collection<CharacterEvent> eventBuffer) {
throw new UnsupportedOperationException("Super class must implement this method");
}
/**
* Read {@link XMLEvent}s off the {@link XMLEventReader} until the corresponding {@link EndElement}
* is found.
*/
protected final void readToEndElement(XMLEventReader eventReader, StartElement event) throws XMLStreamException {
final Deque<QName> elementStack = new LinkedList<QName>();
elementStack.push(event.getName());
while (!elementStack.isEmpty()) {
final XMLEvent nextEvent = eventReader.nextEvent();
if (nextEvent.isStartElement()) {
final StartElement startElement = nextEvent.asStartElement();
elementStack.push(startElement.getName());
}
else if (nextEvent.isEndElement()) {
final QName lastStart = elementStack.pop();
final EndElement endElement = nextEvent.asEndElement();
if (!lastStart.equals(endElement.getName())) {
throw new XMLStreamException("Invalid XML Structure, expected EndElement " + lastStart + " but found EndElment " + endElement.getName());
}
}
}
}
}