org.opencastproject.mediapackage.MediaPackageElementParser Maven / Gradle / Ivy
/*
* Licensed to The Apereo Foundation under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
*
* The Apereo Foundation licenses this file to you under the Educational
* Community 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://opensource.org/licenses/ecl2.txt
*
* 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.opencastproject.mediapackage;
import static org.apache.commons.io.IOUtils.toInputStream;
import org.opencastproject.util.XmlSafeParser;
import org.opencastproject.util.data.Function;
import org.xml.sax.SAXException;
import java.io.IOException;
import java.io.StringWriter;
import java.util.Collection;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
/**
* Convenience implementation that supports serializing and deserializing media package elements.
*/
public final class MediaPackageElementParser {
/**
* Private constructor to prohibit instances of this static utility class.
*/
private MediaPackageElementParser() {
// Nothing to do
}
/**
* Serializes the media package element to a string.
*
* @param element
* the element
* @return the serialized media package element
* @throws MediaPackageException
* if serialization failed
*/
public static String getAsXml(MediaPackageElement element) throws MediaPackageException {
if (element == null)
throw new IllegalArgumentException("Mediapackage element must not be null");
StringWriter writer = new StringWriter();
Marshaller m = null;
try {
m = MediaPackageImpl.context.createMarshaller();
m.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, false);
m.marshal(element, writer);
return writer.toString();
} catch (JAXBException e) {
throw new MediaPackageException(e.getLinkedException() != null ? e.getLinkedException() : e);
}
}
/** {@link #getAsXml(MediaPackageElement)} as function. */
public static Function getAsXml() {
return new Function.X() {
@Override protected String xapply(MediaPackageElement elem) throws Exception {
return getAsXml(elem);
}
};
}
/**
* Parses the serialized media package element and returns its object representation.
*
* @param xml
* the serialized element
* @return the media package element instance
* @throws MediaPackageException
* if de-serializing the element fails
*/
public static MediaPackageElement getFromXml(String xml) throws MediaPackageException {
Unmarshaller m = null;
try {
m = MediaPackageImpl.context.createUnmarshaller();
return (MediaPackageElement) m.unmarshal(XmlSafeParser.parse(toInputStream(xml)));
} catch (JAXBException e) {
throw new MediaPackageException(e.getLinkedException() != null ? e.getLinkedException() : e);
} catch (IOException | SAXException e) {
throw new MediaPackageException(e);
}
}
/**
* Serializes media package element list to a string.
*
* @param elements
* element list to be serialized
* @return serialized media package element list
* @throws MediaPackageException
* if serialization fails
*/
public static String getArrayAsXml(Collection elements) throws MediaPackageException {
// TODO write real serialization function
if (elements == null || elements.isEmpty()) return "";
try {
StringBuilder builder = new StringBuilder();
Iterator it = elements.iterator();
builder.append(getAsXml(it.next()));
while (it.hasNext()) {
builder.append("###");
builder.append(getAsXml(it.next()));
}
return builder.toString();
} catch (Exception e) {
if (e instanceof MediaPackageException) {
throw (MediaPackageException) e;
} else {
throw new MediaPackageException(e);
}
}
}
/**
* Parses the serialized media package element list.
*
* @param xml
* String to be parsed
* @return parsed media package element list
* @throws MediaPackageException
* if de-serialization fails
*/
public static List getArrayFromXml(String xml) throws MediaPackageException {
// TODO write real deserialization function
try {
List elements = new LinkedList();
String[] xmlArray = xml.split("###");
for (String xmlElement : xmlArray) {
if ("".equals(xmlElement.trim())) continue;
elements.add(getFromXml(xmlElement.trim()));
}
return elements;
} catch (Exception e) {
if (e instanceof MediaPackageException) {
throw (MediaPackageException) e;
} else {
throw new MediaPackageException(e);
}
}
}
/**
* Same as getArrayFromXml(), but throwing a RuntimeException instead of a checked exception. Useful in streams.
*
* @param xml
* String to be parsed
* @return parsed media package element list
*
* @throws MediaPackageRuntimeException
* if de-serialization fails
*/
public static List getArrayFromXmlUnchecked(String xml) {
try {
return getArrayFromXml(xml);
} catch (MediaPackageException e) {
throw new MediaPackageRuntimeException(e);
}
}
}