com.rometools.rome.io.impl.DCModuleParser Maven / Gradle / Ivy
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/*
* 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.rometools.rome.io.impl;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import org.jdom2.Attribute;
import org.jdom2.Element;
import org.jdom2.Namespace;
import com.rometools.rome.feed.module.DCModule;
import com.rometools.rome.feed.module.DCModuleImpl;
import com.rometools.rome.feed.module.DCSubject;
import com.rometools.rome.feed.module.DCSubjectImpl;
import com.rometools.rome.feed.module.Module;
import com.rometools.rome.io.ModuleParser;
/**
* 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);
@Override
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.
*
*
* @param dcRoot the root element containing the module elements.
* @param locale for date/time parsing
* @return the module parsed from the element tree, null if none.
*/
@Override
public Module parse(final Element dcRoot, final Locale locale) {
boolean foundSomething = false;
final DCModule dcm = new DCModuleImpl();
final List titles = dcRoot.getChildren("title", getDCNamespace());
if (!titles.isEmpty()) {
foundSomething = true;
dcm.setTitles(parseElementList(titles));
}
final List creators = dcRoot.getChildren("creator", getDCNamespace());
if (!creators.isEmpty()) {
foundSomething = true;
dcm.setCreators(parseElementList(creators));
}
final List subjects = dcRoot.getChildren("subject", getDCNamespace());
if (!subjects.isEmpty()) {
foundSomething = true;
dcm.setSubjects(parseSubjects(subjects));
}
final List descriptions = dcRoot.getChildren("description", getDCNamespace());
if (!descriptions.isEmpty()) {
foundSomething = true;
dcm.setDescriptions(parseElementList(descriptions));
}
final List publishers = dcRoot.getChildren("publisher", getDCNamespace());
if (!publishers.isEmpty()) {
foundSomething = true;
dcm.setPublishers(parseElementList(publishers));
}
final List contributors = dcRoot.getChildren("contributor", getDCNamespace());
if (!contributors.isEmpty()) {
foundSomething = true;
dcm.setContributors(parseElementList(contributors));
}
final List dates = dcRoot.getChildren("date", getDCNamespace());
if (!dates.isEmpty()) {
foundSomething = true;
dcm.setDates(parseElementListDate(dates, locale));
}
final List types = dcRoot.getChildren("type", getDCNamespace());
if (!types.isEmpty()) {
foundSomething = true;
dcm.setTypes(parseElementList(types));
}
final List formats = dcRoot.getChildren("format", getDCNamespace());
if (!formats.isEmpty()) {
foundSomething = true;
dcm.setFormats(parseElementList(formats));
}
final List identifiers = dcRoot.getChildren("identifier", getDCNamespace());
if (!identifiers.isEmpty()) {
foundSomething = true;
dcm.setIdentifiers(parseElementList(identifiers));
}
final List sources = dcRoot.getChildren("source", getDCNamespace());
if (!sources.isEmpty()) {
foundSomething = true;
dcm.setSources(parseElementList(sources));
}
final List languages = dcRoot.getChildren("language", getDCNamespace());
if (!languages.isEmpty()) {
foundSomething = true;
dcm.setLanguages(parseElementList(languages));
}
final List relations = dcRoot.getChildren("relation", getDCNamespace());
if (!relations.isEmpty()) {
foundSomething = true;
dcm.setRelations(parseElementList(relations));
}
final List coverages = dcRoot.getChildren("coverage", getDCNamespace());
if (!coverages.isEmpty()) {
foundSomething = true;
dcm.setCoverages(parseElementList(coverages));
}
final List rights = dcRoot.getChildren("rights", getDCNamespace());
if (!rights.isEmpty()) {
foundSomething = true;
dcm.setRightsList(parseElementList(rights));
}
if (foundSomething) {
return dcm;
} else {
return null;
}
}
/**
* Utility method to parse a taxonomy from an element.
*
*
* @param desc the taxonomy description element.
* @return the string contained in the resource of the element.
*/
protected final String getTaxonomy(final Element desc) {
String taxonomy = null;
final Element topic = desc.getChild("topic", getTaxonomyNamespace());
if (topic != null) {
final Attribute resource = topic.getAttribute("resource", getRDFNamespace());
if (resource != null) {
taxonomy = resource.getValue();
}
}
return taxonomy;
}
/**
* Utility method to parse a list of subjects out of a list of elements.
*
*
* @param eList the element list to parse.
* @return a list of subjects parsed from the elements.
*/
protected final List parseSubjects(final List eList) {
final List subjects = new ArrayList();
for (final Element eSubject : eList) {
final Element description = eSubject.getChild("Description", getRDFNamespace());
if (description != null) {
final String taxonomy = getTaxonomy(description);
final List values = description.getChildren("value", getRDFNamespace());
for (final Element value : values) {
final DCSubject subject = new DCSubjectImpl();
subject.setTaxonomyUri(taxonomy);
subject.setValue(value.getText());
subjects.add(subject);
}
} else {
final 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.
*
*
* @param elements the list of elements to parse.
* @return the list of strings
*/
protected final List parseElementList(final List elements) {
final List values = new ArrayList();
for (final Element element : elements) {
values.add(element.getText());
}
return values;
}
/**
* Utility method to parse a list of dates out of a list of elements.
*
*
* @param elements the list of elements to parse.
* @return the list of dates.
*/
protected final List parseElementListDate(final List elements, final Locale locale) {
final List values = new ArrayList();
for (final Element element : elements) {
values.add(DateParser.parseDate(element.getText(), locale));
}
return values;
}
}