/*
* Copyright 2004 Sun Microsystems, Inc.
*
* 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 com.sun.syndication.io.impl;
import com.sun.syndication.feed.module.DCModuleImpl;
import com.sun.syndication.feed.module.DCSubjectImpl;
import com.sun.syndication.feed.module.Module;
import com.sun.syndication.feed.module.DCModule;
import com.sun.syndication.feed.module.DCSubject;
import com.sun.syndication.io.ModuleParser;
import com.sun.syndication.io.WireFeedParser;
import org.jdom.Attribute;
import org.jdom.Element;
import org.jdom.Namespace;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
/**
* Parser for the Dublin Core module.
*/
public class DCModuleParser implements ModuleParser {
private static final String RDF_URI = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
private static final String TAXO_URI = "http://purl.org/rss/1.0/modules/taxonomy/";
private static final Namespace DC_NS = Namespace.getNamespace(DCModule.URI);
private static final Namespace RDF_NS = Namespace.getNamespace(RDF_URI);
private static final Namespace TAXO_NS = Namespace.getNamespace(TAXO_URI);
public final String getNamespaceUri() {
return DCModule.URI;
}
private final Namespace getDCNamespace() {
return DC_NS;
}
private final Namespace getRDFNamespace() {
return RDF_NS;
}
private final Namespace getTaxonomyNamespace() {
return TAXO_NS;
}
/**
* Parse an element tree and return the module found in it.
* <p>
* @param dcRoot the root element containing the module elements.
* @return the module parsed from the element tree, <i>null</i> if none.
*/
public Module parse(Element dcRoot) {
boolean foundSomething = false;
DCModule dcm = new DCModuleImpl();
List eList = dcRoot.getChildren("title", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setTitles(parseElementList(eList));
}
eList = dcRoot.getChildren("creator", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setCreators(parseElementList(eList));
}
eList = dcRoot.getChildren("subject", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setSubjects(parseSubjects(eList));
}
eList = dcRoot.getChildren("description", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setDescriptions(parseElementList(eList));
}
eList = dcRoot.getChildren("publisher", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setPublishers(parseElementList(eList));
}
eList = dcRoot.getChildren("contributor", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setContributors(parseElementList(eList));
}
eList = dcRoot.getChildren("date", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setDates(parseElementListDate(eList));
}
eList = dcRoot.getChildren("type", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setTypes(parseElementList(eList));
}
eList = dcRoot.getChildren("format", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setFormats(parseElementList(eList));
}
eList = dcRoot.getChildren("identifier", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setIdentifiers(parseElementList(eList));
}
eList = dcRoot.getChildren("source", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setSources(parseElementList(eList));
}
eList = dcRoot.getChildren("language", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setLanguages(parseElementList(eList));
}
eList = dcRoot.getChildren("relation", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setRelations(parseElementList(eList));
}
eList = dcRoot.getChildren("coverage", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setCoverages(parseElementList(eList));
}
eList = dcRoot.getChildren("rights", getDCNamespace());
if (eList.size() > 0) {
foundSomething = true;
dcm.setRightsList(parseElementList(eList));
}
return (foundSomething) ? dcm : null;
}
/**
* Utility method to parse a taxonomy from an element.
* <p>
* @param desc the taxonomy description element.
* @return the string contained in the resource of the element.
*/
protected final String getTaxonomy(Element desc) {
String d = null;
Element taxo = desc.getChild("topic", getTaxonomyNamespace());
if (taxo!=null) {
Attribute a = taxo.getAttribute("resource", getRDFNamespace());
if (a!=null) {
d = a.getValue();
}
}
return d;
}
/**
* Utility method to parse a list of subjects out of a list of elements.
* <p>
* @param eList the element list to parse.
* @return a list of subjects parsed from the elements.
*/
protected final List parseSubjects(List eList) {
List subjects = new ArrayList();
for (Iterator i = eList.iterator(); i.hasNext();) {
Element eSubject = (Element) i.next();
Element eDesc = eSubject.getChild("Description", getRDFNamespace());
if (eDesc != null) {
String taxonomy = getTaxonomy(eDesc);
List eValues = eDesc.getChildren("value", getRDFNamespace());
for (Iterator v = eValues.iterator(); v.hasNext();) {
Element eValue = (Element) v.next();
DCSubject subject = new DCSubjectImpl();
subject.setTaxonomyUri(taxonomy);
subject.setValue(eValue.getText());
subjects.add(subject);
}
} else {
DCSubject subject = new DCSubjectImpl();
subject.setValue(eSubject.getText());
subjects.add(subject);
}
}
return subjects;
}
/**
* Utility method to parse a list of strings out of a list of elements.
* <p>
* @param eList the list of elements to parse.
* @return the list of strings
*/
protected final List parseElementList(List eList) {
List values= new ArrayList();
for (Iterator i = eList.iterator(); i.hasNext();) {
Element e = (Element) i.next();
values.add(e.getText());
}
return values;
}
/**
* Utility method to parse a list of dates out of a list of elements.
* <p>
* @param eList the list of elements to parse.
* @return the list of dates.
*/
protected final List parseElementListDate(List eList) {
List values = new ArrayList();
for (Iterator i = eList.iterator(); i.hasNext();) {
Element e = (Element) i.next();
values.add(DateParser.parseDate(e.getText()));
}
return values;
}
}