/**
* Copyright 2005-2014 Restlet
*
* The contents of this file are subject to the terms of one of the following
* open source licenses: Apache 2.0 or or EPL 1.0 (the "Licenses"). You can
* select the license that you prefer but you may not use this file except in
* compliance with one of these Licenses.
*
* You can obtain a copy of the Apache 2.0 license at
* http://www.opensource.org/licenses/apache-2.0
*
* You can obtain a copy of the EPL 1.0 license at
* http://www.opensource.org/licenses/eclipse-1.0
*
* See the Licenses for the specific language governing permissions and
* limitations under the Licenses.
*
* Alternatively, you can obtain a royalty free commercial license with less
* limitations, transferable or non-transferable, directly at
* http://restlet.com/products/restlet-framework
*
* Restlet is a registered trademark of Restlet S.A.S.
*/
package org.restlet.ext.atom;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.restlet.Client;
import org.restlet.Context;
import org.restlet.Request;
import org.restlet.data.MediaType;
import org.restlet.data.Method;
import org.restlet.data.Reference;
import org.restlet.engine.util.DateUtils;
import org.restlet.ext.atom.internal.FeedContentReader;
import org.restlet.ext.xml.SaxRepresentation;
import org.restlet.ext.xml.XmlWriter;
import org.restlet.representation.Representation;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;
/**
* Atom Feed Document, acting as a component for metadata and data associated
* with the feed.
*
* @author Jerome Louvel
*/
public class Feed extends SaxRepresentation {
/** Atom Syndication Format namespace. */
public final static String ATOM_NAMESPACE = "http://www.w3.org/2005/Atom";
/** XHTML namespace. */
public final static String XHTML_NAMESPACE = "http://www.w3.org/1999/xhtml";
/** The authors of the feed. */
private volatile List<Person> authors;
/**
* The base reference used to resolve relative references found within the
* scope of the xml:base attribute.
*/
private volatile Reference baseReference;
/** The categories associated with the feed. */
private volatile List<Category> categories;
/** The contributors to the feed. */
private volatile List<Person> contributors;
/**
* Individual entries, acting as a components for associated metadata and
* data.
*/
private List<Entry> entries;
/** The agent used to generate a feed. */
private volatile Generator generator;
/** Image that provides iconic visual identification for a feed. */
private volatile Reference icon;
/** Permanent, universally unique identifier for the feed. */
private volatile String id;
/** The references from the entry to Web resources. */
private volatile List<Link> links;
/** Image that provides visual identification for a feed. */
private volatile Reference logo;
/** Information about rights held in and over an feed. */
private volatile Text rights;
/** Short summary, abstract, or excerpt of an feed. */
private volatile Text subtitle;
/** The human-readable title for the feed. */
private volatile Text title;
/** Most recent moment when the entry was modified in a significant way. */
private volatile Date updated;
/**
* Constructor.
*/
public Feed() {
super(MediaType.APPLICATION_ATOM);
setNamespaceAware(true);
this.authors = null;
this.categories = null;
this.contributors = null;
this.generator = null;
this.icon = null;
this.id = null;
this.links = null;
this.logo = null;
this.rights = null;
this.subtitle = null;
this.title = null;
this.updated = null;
this.entries = null;
}
/**
* Constructor.
*
* @param clientDispatcher
* The client HTTP dispatcher.
* @param feedUri
* The feed URI.
* @throws IOException
*/
public Feed(Client clientDispatcher, String feedUri) throws IOException {
this(clientDispatcher.handle(new Request(Method.GET, feedUri))
.getEntity());
}
/**
* Constructor.
*
* @param context
* The context from which the client dispatcher will be
* retrieved.
* @param feedUri
* The feed URI.
* @throws IOException
*/
public Feed(Context context, String feedUri) throws IOException {
this(context.getClientDispatcher()
.handle(new Request(Method.GET, feedUri)).getEntity());
}
/**
* Constructor.
*
* @param xmlFeed
* The XML feed document.
* @throws IOException
*/
public Feed(Representation xmlFeed) throws IOException {
super(xmlFeed);
setNamespaceAware(true);
parse(new FeedContentReader(this));
}
/**
* Constructor.
*
* @param xmlFeed
* The XML feed document.
* @param feedReader
* Custom feed reader.
* @throws IOException
*/
public Feed(Representation xmlFeed, FeedReader feedReader)
throws IOException {
super(xmlFeed);
setNamespaceAware(true);
parse(new FeedContentReader(this, feedReader));
}
/**
* Constructor.
*
* @param feedUri
* The feed URI.
* @throws IOException
*/
public Feed(String feedUri) throws IOException {
this(new Client(new Reference(feedUri).getSchemeProtocol()), feedUri);
}
/**
* Returns the authors of the feed.
*
* @return The authors of the feed.
*/
public List<Person> getAuthors() {
// Lazy initialization with double-check.
List<Person> a = this.authors;
if (a == null) {
synchronized (this) {
a = this.authors;
if (a == null) {
this.authors = a = new ArrayList<Person>();
}
}
}
return a;
}
/**
* Returns the base reference used to resolve relative references found
* within the scope of the xml:base attribute.
*
* @return The base reference used to resolve relative references found
* within the scope of the xml:base attribute.
*/
public Reference getBaseReference() {
return baseReference;
}
/**
* Returns the categories associated with the feed.
*
* @return The categories associated with the feed.
*/
public List<Category> getCategories() {
// Lazy initialization with double-check.
List<Category> c = this.categories;
if (c == null) {
synchronized (this) {
c = this.categories;
if (c == null) {
this.categories = c = new ArrayList<Category>();
}
}
}
return c;
}
/**
* Returns the contributors to the feed.
*
* @return The contributors to the feed.
*/
public List<Person> getContributors() {
// Lazy initialization with double-check.
List<Person> c = this.contributors;
if (c == null) {
synchronized (this) {
c = this.contributors;
if (c == null) {
this.contributors = c = new ArrayList<Person>();
}
}
}
return c;
}
/**
* Returns the individual entries, acting as a components for associated
* metadata and data.
*
* @return The individual entries, acting as a components for associated
* metadata and data.
*/
public List<Entry> getEntries() {
// Lazy initialization with double-check.
List<Entry> e = this.entries;
if (e == null) {
synchronized (this) {
e = this.entries;
if (e == null) {
this.entries = e = new ArrayList<Entry>();
}
}
}
return e;
}
/**
* Returns the agent used to generate a feed.
*
* @return The agent used to generate a feed.
*/
public Generator getGenerator() {
return this.generator;
}
/**
* Returns the image that provides iconic visual identification for a feed.
*
* @return The image that provides iconic visual identification for a feed.
*/
public Reference getIcon() {
return this.icon;
}
/**
* Returns the permanent, universally unique identifier for the feed.
*
* @return The permanent, universally unique identifier for the feed.
*/
public String getId() {
return this.id;
}
/**
* Returns the references from the entry to Web resources.
*
* @return The references from the entry to Web resources.
*/
public List<Link> getLinks() {
// Lazy initialization with double-check.
List<Link> l = this.links;
if (l == null) {
synchronized (this) {
l = this.links;
if (l == null) {
this.links = l = new ArrayList<Link>();
}
}
}
return l;
}
/**
* Returns the image that provides visual identification for a feed.
*
* @return The image that provides visual identification for a feed.
*/
public Reference getLogo() {
return this.logo;
}
/**
* Returns the information about rights held in and over an feed.
*
* @return The information about rights held in and over an feed.
*/
public Text getRights() {
return this.rights;
}
/**
* Returns the short summary, abstract, or excerpt of an feed.
*
* @return The short summary, abstract, or excerpt of an feed.
*/
public Text getSubtitle() {
return this.subtitle;
}
/**
* Returns the human-readable title for the feed.
*
* @return The human-readable title for the feed.
*/
public Text getTitle() {
return this.title;
}
/**
* Returns the most recent moment when the entry was modified in a
* significant way.
*
* @return The most recent moment when the entry was modified in a
* significant way.
*/
public Date getUpdated() {
return this.updated;
}
/**
* Sets the base reference used to resolve relative references found within
* the scope of the xml:base attribute.
*
* @param baseReference
* The base reference used to resolve relative references found
* within the scope of the xml:base attribute.
*/
public void setBaseReference(Reference baseReference) {
this.baseReference = baseReference;
}
/**
* Sets the base URI used to resolve relative references found within the
* scope of the xml:base attribute.
*
* @param baseUri
* The base URI used to resolve relative references found within
* the scope of the xml:base attribute.
*/
public void setBaseReference(String baseUri) {
setBaseReference(new Reference(baseUri));
}
/**
* Sets the agent used to generate a feed.
*
* @param generator
* The agent used to generate a feed.
*/
public void setGenerator(Generator generator) {
this.generator = generator;
}
/**
* Sets the image that provides iconic visual identification for a feed.
*
* @param icon
* The image that provides iconic visual identification for a
* feed.
*/
public void setIcon(Reference icon) {
this.icon = icon;
}
/**
* Sets the permanent, universally unique identifier for the feed.
*
* @param id
* The permanent, universally unique identifier for the feed.
*/
public void setId(String id) {
this.id = id;
}
/**
* Sets the image that provides visual identification for a feed.
*
* @param logo
* The image that provides visual identification for a feed.
*/
public void setLogo(Reference logo) {
this.logo = logo;
}
/**
* Sets the information about rights held in and over an feed.
*
* @param rights
* The information about rights held in and over an feed.
*/
public void setRights(String rights) {
setRights(new Text(rights));
}
/**
* Sets the information about rights held in and over an feed.
*
* @param rights
* The information about rights held in and over an feed.
*/
public void setRights(Text rights) {
this.rights = rights;
}
/**
* Sets the short summary, abstract, or excerpt of an feed.
*
* @param subtitle
* The short summary, abstract, or excerpt of an feed.
*/
public void setSubtitle(String subtitle) {
setSubtitle(new Text(subtitle));
}
/**
* Sets the short summary, abstract, or excerpt of an feed.
*
* @param subtitle
* The short summary, abstract, or excerpt of an feed.
*/
public void setSubtitle(Text subtitle) {
this.subtitle = subtitle;
}
/**
* Sets the human-readable title for the feed.
*
* @param title
* The human-readable title for the feed.
*/
public void setTitle(String title) {
setTitle(new Text(title));
}
/**
* Sets the human-readable title for the feed.
*
* @param title
* The human-readable title for the feed.
*/
public void setTitle(Text title) {
this.title = title;
}
/**
* Sets the most recent moment when the feed was modified in a significant
* way.
*
* @param updated
* The most recent moment when the feed was modified in a
* significant way.
*/
public void setUpdated(Date updated) {
this.updated = DateUtils.unmodifiable(updated);
}
/**
* Writes the representation to a XML writer.
*
* @param writer
* The XML writer to write to.
* @throws IOException
*/
@Override
public void write(XmlWriter writer) throws IOException {
try {
writer.setPrefix(ATOM_NAMESPACE, "");
writer.setDataFormat(true);
writer.setIndentStep(3);
writer.startDocument();
writeElement(writer);
writer.endDocument();
} catch (SAXException e) {
IOException ioe = new IOException(
"Unable to write the Atom feed document.");
ioe.initCause(e);
throw ioe;
}
}
/**
* Writes the current object as an XML element using the given SAX writer.
*
* @param writer
* The SAX writer.
* @throws SAXException
*/
public void writeElement(XmlWriter writer) throws SAXException {
writer.startElement(ATOM_NAMESPACE, "feed");
if (getAuthors() != null) {
for (final Person person : getAuthors()) {
person.writeElement(writer, "author");
}
}
if (getCategories() != null) {
for (final Category category : getCategories()) {
category.writeElement(writer);
}
}
if (getContributors() != null) {
for (final Person person : getContributors()) {
person.writeElement(writer, "contributor");
}
}
if (getGenerator() != null) {
getGenerator().writeElement(writer);
}
if (getIcon() != null) {
writer.dataElement(ATOM_NAMESPACE, "icon", getIcon().toString());
}
if (getId() != null) {
writer.dataElement(ATOM_NAMESPACE, "id", null,
new AttributesImpl(), getId());
}
if (getLinks() != null) {
for (final Link link : getLinks()) {
link.writeElement(writer);
}
}
if ((getLogo() != null) && (getLogo().toString() != null)) {
writer.dataElement(ATOM_NAMESPACE, "logo", getLogo().toString());
}
if (getRights() != null) {
getRights().writeElement(writer, "rights");
}
if (getSubtitle() != null) {
getSubtitle().writeElement(writer, "subtitle");
}
if (getTitle() != null) {
getTitle().writeElement(writer, "title");
}
if (getUpdated() != null) {
Text.writeElement(writer, getUpdated(), ATOM_NAMESPACE, "updated");
}
if (getEntries() != null) {
for (final Entry entry : getEntries()) {
entry.writeElement(writer);
}
}
writer.endElement(ATOM_NAMESPACE, "feed");
}
}