/*
* 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.Module;
import com.sun.syndication.feed.module.DCModule;
import com.sun.syndication.feed.module.DCSubject;
import com.sun.syndication.io.ModuleGenerator;
import org.jdom.Attribute;
import org.jdom.Element;
import org.jdom.Namespace;
import java.util.ArrayList;
import java.util.Date;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
import java.util.HashSet;
import java.util.Collections;
/**
* Feed Generator for DublinCore Module.
* <p/>
*
* @author Elaine Chien
*
*/
public class DCModuleGenerator implements ModuleGenerator {
private static final String DC_URI = "http://purl.org/dc/elements/1.1/";
private static final String TAXO_URI = "http://purl.org/rss/1.0/modules/taxonomy/";
private static final String RDF_URI = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
private static final Namespace DC_NS = Namespace.getNamespace("dc", DC_URI);
private static final Namespace TAXO_NS = Namespace.getNamespace("taxo", TAXO_URI);
private static final Namespace RDF_NS = Namespace.getNamespace("rdf", RDF_URI);
private static final Set NAMESPACES;
static {
Set nss = new HashSet();
nss.add(DC_NS);
nss.add(TAXO_NS);
nss.add(RDF_NS);
NAMESPACES = Collections.unmodifiableSet(nss);
}
public final String getNamespaceUri() {
return DC_URI;
}
private final Namespace getDCNamespace() {
return DC_NS;
}
private final Namespace getRDFNamespace() {
return RDF_NS;
}
private final Namespace getTaxonomyNamespace() {
return TAXO_NS;
}
/**
* Returns a set with all the URIs (JDOM Namespace elements) this module
* generator uses.
* <p/>
* It is used by the the feed generators to add their namespace definition
* in the root element of the generated document (forward-missing of
* Java 5.0 Generics).
* <p/>
*
* @return a set with all the URIs this module generator uses.
*/
public final Set getNamespaces() {
return NAMESPACES;
}
/**
* Populate an element tree with elements for a module.
* <p>
* @param module the module to populate from.
* @param element the root element to attach child elements to.
*/
public final void generate(Module module, Element element) {
DCModule dcModule = (DCModule) module;
if (dcModule.getTitle() != null) {
element.addContent(generateSimpleElementList("title", dcModule.getTitles()));
}
if (dcModule.getCreator() != null) {
element.addContent(generateSimpleElementList("creator", dcModule.getCreators()));
}
List subjects = dcModule.getSubjects();
for (int i = 0; i < subjects.size(); i++) {
element.addContent(generateSubjectElement((DCSubject) subjects.get(i)));
}
if (dcModule.getDescription() != null) {
element.addContent(generateSimpleElementList("description", dcModule.getDescriptions()));
}
if (dcModule.getPublisher() != null) {
element.addContent(generateSimpleElementList("publisher", dcModule.getPublishers()));
}
if (dcModule.getContributors() != null) {
element.addContent(generateSimpleElementList("contributor", dcModule.getContributors()));
}
if (dcModule.getDate() != null) {
for (Iterator i = dcModule.getDates().iterator(); i.hasNext();) {
element.addContent(generateSimpleElement("date",
DateParser.formatW3CDateTime((Date) i.next())));
}
}
if (dcModule.getType() != null) {
element.addContent(generateSimpleElementList("type", dcModule.getTypes()));
}
if (dcModule.getFormat() != null) {
element.addContent(generateSimpleElementList("format", dcModule.getFormats()));
}
if (dcModule.getIdentifier() != null) {
element.addContent(generateSimpleElementList("identifier", dcModule.getIdentifiers()));
}
if (dcModule.getSource() != null) {
element.addContent(generateSimpleElementList("source", dcModule.getSources()));
}
if (dcModule.getLanguage() != null) {
element.addContent(generateSimpleElementList("language", dcModule.getLanguages()));
}
if (dcModule.getRelation() != null) {
element.addContent(generateSimpleElementList("relation", dcModule.getRelations()));
}
if (dcModule.getCoverage() != null) {
element.addContent(generateSimpleElementList("coverage", dcModule.getCoverages()));
}
if (dcModule.getRights() != null) {
element.addContent(generateSimpleElementList("rights", dcModule.getRightsList()));
}
}
/**
* Utility method to generate an element for a subject.
* <p>
* @param subject the subject to generate an element for.
* @return the element for the subject.
*/
protected final Element generateSubjectElement(DCSubject subject) {
Element subjectElement = new Element("subject", getDCNamespace());
if (subject.getTaxonomyUri() != null) {
Element descriptionElement = new Element("Description", getRDFNamespace());
Element topicElement = new Element("topic", getTaxonomyNamespace());
Attribute resourceAttribute = new Attribute("resource", subject.getTaxonomyUri(), getRDFNamespace());
topicElement.setAttribute(resourceAttribute);
descriptionElement.addContent(topicElement);
if (subject.getValue() != null) {
Element valueElement = new Element("value", getRDFNamespace());
valueElement.addContent(subject.getValue());
descriptionElement.addContent(valueElement);
}
subjectElement.addContent(descriptionElement);
} else {
subjectElement.addContent(subject.getValue());
}
return subjectElement;
}
/**
* Utility method to generate a single element containing a string.
* <p>
* @param name the name of the elment to generate.
* @param value the value of the text in the element.
* @return the element generated.
*/
protected final Element generateSimpleElement(String name, String value) {
Element element = new Element(name, getDCNamespace());
element.addContent(value);
return element;
}
/**
* Utility method to generate a list of simple elements.
* <p>
* @param name the name of the element list to generate.
* @param value the list of values for the elements.
* @return a list of Elements created.
*/
protected final List generateSimpleElementList(String name, List value) {
List elements = new ArrayList();
for (Iterator i = value.iterator(); i.hasNext();) {
elements.add(generateSimpleElement(name, (String) i.next()));
}
return elements;
}
}