//
// Informa -- RSS Library for Java
// Copyright (c) 2002 by Niko Schmuck
//
// Niko Schmuck
// http://sourceforge.net/projects/informa
// mailto:niko_schmuck@users.sourceforge.net
//
// This library is free software.
//
// You may redistribute it and/or modify it under the terms of the GNU
// Lesser General Public License as published by the Free Software Foundation.
//
// Version 2.1 of the license should be included with this distribution in
// the file LICENSE. If the license is not included with this distribution,
// you may find a copy at the FSF web site at 'www.gnu.org' or 'www.fsf.org',
// or you may write to the Free Software Foundation, 675 Mass Ave, Cambridge,
// MA 02139 USA.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied waranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// Lesser General Public License for more details.
//
// $Id: RSS_2_0_Exporter.java,v 1.7 2007/01/05 23:07:58 niko_schmuck Exp $
package de.nava.informa.exporters;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.text.SimpleDateFormat;
import java.util.Collection;
import java.util.Iterator;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.Namespace;
import org.jdom.output.Format;
import org.jdom.output.XMLOutputter;
import de.nava.informa.core.ChannelExporterIF;
import de.nava.informa.core.ChannelIF;
import de.nava.informa.core.ItemIF;
import de.nava.informa.core.CategoryIF;
import de.nava.informa.utils.ParserUtils;
/**
* A channel exporter that can write channel objects out into the interchange
* syntax defined by RSS 2.0.
* </p>
*
* @author Sami Alireza, Niko Schmuck
*/
public class RSS_2_0_Exporter implements ChannelExporterIF {
private static final String RSS_VERSION = "2.0";
/**
* RSS 1.0 Dublin Core namespace
*/
private static final String NS_DC = "http://purl.org/dc/elements/1.1/";
/**
* RSS 1.0 Syndication Module namespace
*/
private static final String NS_SY = "http://purl.org/rss/1.0/modules/syndication/";
private static final String NS_ADMIN = "http://webns.net/mvcb/";
//private static final String NS_RDF = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
private static SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ssZ");
private Writer writer;
private String encoding;
/**
* Creates a channel exporter bound to the file given in the argument. The
* channel will be written out in the UTF-8 encoding.
*
* @param filename - The name of the file to which the channel object is to be
* written.
*/
public RSS_2_0_Exporter(String filename) throws IOException {
this(new File(filename), "utf-8");
}
/**
* Creates a channel exporter bound to the file given in the argument. The
* <p/>
* channel will be written out in the UTF-8 encoding.
*
* @param file - The file object to which the channel object is to be
* <p/>
* written.
*/
public RSS_2_0_Exporter(File file) throws IOException {
this(file, "utf-8");
}
/**
* Creates a channel exporter bound to the file given in the arguments.
*
* @param file - The file object to which the channel object is to be
* <p/>
* written.
* @param encoding -
* <p/>
* The character encoding to write the channel object in.
*/
public RSS_2_0_Exporter(File file, String encoding) throws IOException {
this.writer = new OutputStreamWriter(new FileOutputStream(file), encoding);
this.encoding = encoding;
}
/**
* Creates a channel exporter bound to the Writer given in the arguments.
*
* @param writer -
* <p/>
* The Writer to which the channel object is to be written.
* @param encoding -
* <p/>
* The character encoding the Writer writes in.
*/
public RSS_2_0_Exporter(Writer writer, String encoding) {
this.writer = writer;
this.encoding = encoding;
}
// ------------------------------------------------------------
// Build a hierarchical category String from CategoryIF
// ------------------------------------------------------------
private Element getCategoryElements(Element elem, CategoryIF category, StringBuffer catString) {
StringBuffer l_catString;
if (catString == null || catString.length() < 1)
l_catString = new StringBuffer(category.getTitle());
else
l_catString = catString.append("/").append(category.getTitle());
Collection categories = category.getChildren();
if (categories.size() == 0) {
elem.addContent(new Element("category").setText(l_catString.toString()));
} else {
Iterator catIt = categories.iterator();
while (catIt.hasNext()) {
CategoryIF childCat = (CategoryIF) catIt.next();
elem = getCategoryElements(elem, childCat, l_catString);
}
}
return elem;
}
// ------------------------------------------------------------
// implementation of ChannelExporterIF interface
// ------------------------------------------------------------
public void write(ChannelIF channel) throws IOException {
if (writer == null) {
throw new RuntimeException("No writer has been initialized.");
}
// create XML outputter with indent: 2 spaces, print new lines.
Format format = Format.getPrettyFormat();
format.setEncoding(encoding);
XMLOutputter outputter = new XMLOutputter(format);
Namespace dcNs = Namespace.getNamespace("dc", NS_DC);
Namespace syNs = Namespace.getNamespace("sy", NS_SY);
Namespace adminNs = Namespace.getNamespace("admin", NS_ADMIN);
//Namespace rdfNs = Namespace.getNamespace("rdf", NS_RDF);
Element rootElem = new Element("rss");
rootElem.addNamespaceDeclaration(dcNs);
rootElem.addNamespaceDeclaration(syNs);
rootElem.addNamespaceDeclaration(adminNs);
rootElem.setAttribute("version", RSS_VERSION);
Element channelElem = new Element("channel");
// rootElem.setAttribute("version");
channelElem.addContent(new Element("title").setText(channel.getTitle()));
if (channel.getSite() != null) {
channelElem.addContent(new Element("link").setText(channel.getSite()
.toString()));
}
channelElem.addContent(new Element("description").setText(channel
.getDescription()));
if (channel.getLanguage() != null) {
channelElem.addContent(new Element("language", dcNs).setText(channel
.getLanguage()));
}
if (channel.getCopyright() != null) {
channelElem.addContent(new Element("copyright", dcNs).setText(channel
.getCopyright()));
}
if (channel.getPubDate() != null) {
channelElem.addContent(new Element("pubDate").setText(ParserUtils
.formatDate(channel.getPubDate())));
}
if (channel.getCategories() != null) {
Collection categories = channel.getCategories();
Iterator catIt = categories.iterator();
while (catIt.hasNext()) {
CategoryIF cat = (CategoryIF) catIt.next();
channelElem = getCategoryElements(channelElem, cat, null);
}
}
if (channel.getUpdateBase() != null) {
channelElem.addContent(new Element("updateBase", syNs).setText(df
.format(channel.getUpdateBase())));
}
if (channel.getUpdatePeriod() != null) {
// don't put out frequency without specifying period
channelElem.addContent(new Element("updateFrequency", syNs)
.setText((new Integer(channel.getUpdateFrequency())).toString()));
channelElem.addContent(new Element("updatePeriod", syNs).setText(channel
.getUpdatePeriod().toString()));
}
// export channel image
if (channel.getImage() != null) {
Element imgElem = new Element("image");
imgElem.addContent(new Element("title")
.setText(channel.getImage().getTitle()));
imgElem.addContent(new Element("url")
.setText(channel.getImage().getLocation().toString()));
imgElem.addContent(new Element("link")
.setText(channel.getImage().getLink().toString()));
imgElem.addContent(new Element("height")
.setText("" + channel.getImage().getHeight()));
imgElem.addContent(new Element("width")
.setText("" + channel.getImage().getWidth()));
imgElem.addContent(new Element("description")
.setText(channel.getImage().getDescription()));
channelElem.addContent(imgElem);
}
// TODO: add exporting textinput field
// if (channel.getTextInput() != null) {
// channelElem.addContent(channel.getTextInput().getElement());
// }
Collection items = channel.getItems();
Iterator it = items.iterator();
while (it.hasNext()) {
ItemIF item = (ItemIF) it.next();
Element itemElem = new Element("item");
itemElem.addContent(new Element("title").setText(item.getTitle()));
if (item.getLink() != null) {
itemElem.addContent(new Element("link").setText(item.getLink()
.toString()));
}
if (item.getDescription() != null) {
itemElem.addContent(new Element("description").setText(item
.getDescription()));
}
if (item.getCategories() != null) {
Collection categories = item.getCategories();
Iterator catIt = categories.iterator();
while (catIt.hasNext()) {
CategoryIF cat = (CategoryIF) catIt.next();
itemElem = getCategoryElements(itemElem, cat, null);
}
}
if (item.getDate() != null) {
itemElem.addContent(new Element("pubDate").setText(ParserUtils
.formatDate(item.getDate())));
}
if (item.getGuid() != null) {
Element guid = new Element("guid").setText(item.getGuid().getLocation());
guid.setAttribute("isPermaLink", Boolean.toString(item.getGuid().isPermaLink()));
itemElem.addContent(guid);
}
if (item.getComments() != null) {
itemElem.addContent(new Element("comments").setText(item.getComments()
.toString()));
}
channelElem.addContent(itemElem);
}
rootElem.addContent(channelElem);
// ---
Document doc = new Document(rootElem);
outputter.output(doc, writer);
// ---
writer.close();
}
}