/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with this
* work for additional information regarding copyright ownership. The ASF
* licenses this file to you 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 org.apache.oodt.cas.product.jaxrs.writers;
import java.io.IOException;
import java.io.OutputStream;
import java.lang.annotation.Annotation;
import java.lang.reflect.Type;
import java.text.ParseException;
import java.util.Date;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.ws.rs.Produces;
import javax.ws.rs.WebApplicationException;
import javax.ws.rs.core.MediaType;
import javax.ws.rs.core.MultivaluedMap;
import javax.ws.rs.ext.MessageBodyWriter;
import javax.ws.rs.ext.Provider;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.apache.oodt.cas.metadata.Metadata;
import org.apache.oodt.cas.metadata.util.PathUtils;
import org.apache.oodt.cas.product.jaxrs.configurations.RssConfiguration;
import org.apache.oodt.cas.product.jaxrs.configurations.RssNamespace;
import org.apache.oodt.cas.product.jaxrs.exceptions.InternalServerErrorException;
import org.apache.oodt.cas.product.jaxrs.resources.DatasetResource;
import org.apache.oodt.cas.product.jaxrs.resources.ProductResource;
import org.apache.oodt.commons.util.DateConvert;
import org.apache.oodt.commons.xml.XMLUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
/**
* A {@link Provider} that writes {@link DatasetResource dataset resources} to
* output streams for HTTP responses with "application/rss+xml" content-type.
* @author rlaidlaw
* @version $Revision$
*/
@Provider
@Produces("application/rss+xml")
public class DatasetRssWriter extends RssWriter
implements MessageBodyWriter<DatasetResource>
{
private static final Logger LOGGER = Logger.getLogger(DatasetRssWriter.class
.getName());
@Override
public long getSize(DatasetResource resource, Class<?> type,
Type genericType, Annotation[] annotations, MediaType mediaType)
{
return -1;
}
@Override
public boolean isWriteable(Class<?> type, Type genericType,
Annotation[] annotations, MediaType mediaType)
{
return true;
}
@Override
public void writeTo(DatasetResource resource, Class<?> type, Type genericType,
Annotation[] annotations, MediaType mediaType,
MultivaluedMap<String, Object> httpHeaders, OutputStream entityStream)
throws IOException, WebApplicationException
{
String productTypeName = resource.getName();
String productTypeId = resource.getId();
String base = getBaseUri() + "dataset";
String query = "?productTypeId=" + productTypeId;
String idLink = base + query;
String selfLink = base + ".rss" + query;
String currentDate = dateFormatter.format(new Date());
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
RssConfiguration configuration = getConfiguration();
try
{
Document doc = factory.newDocumentBuilder().newDocument();
Element rss = XMLUtils.addNode(doc, doc, "rss");
XMLUtils.addAttribute(doc, rss, "version", "2.0");
XMLUtils.addAttribute(doc, rss, "xmlns:atom",
"http://www.w3.org/2005/Atom");
if (configuration != null)
{
// Add namespaces defined in the configuration file.
for (RssNamespace namespace : configuration.getNamespaceList())
{
XMLUtils.addAttribute(doc, rss, "xmlns:" + namespace.getPrefix(),
namespace.getUriString());
}
// Get channel link information, if specified in the configuration.
String channelLink = configuration.getChannelLink();
if (channelLink != null && !channelLink.equals(""))
{
Metadata channelMetadata = new Metadata();
channelMetadata.addMetadata("ProductType", productTypeName);
channelMetadata.addMetadata("ProductTypeId", productTypeId);
channelMetadata.addMetadata("BaseUrl", base);
idLink = PathUtils.replaceEnvVariables(channelLink, channelMetadata);
}
}
Element channel = XMLUtils.addNode(doc, rss, "channel");
XMLUtils.addNode(doc, channel, "title", productTypeName);
Element atomLink = XMLUtils.addNode(doc, channel, "atom:link");
XMLUtils.addAttribute(doc, atomLink, "href", selfLink);
XMLUtils.addAttribute(doc, atomLink, "rel", "self");
XMLUtils.addAttribute(doc, atomLink, "type", "application/rss+xml");
XMLUtils.addNode(doc, channel, "link", idLink);
XMLUtils.addNode(doc, channel, "description", productTypeName);
XMLUtils.addNode(doc, channel, "language", LANGUAGE);
XMLUtils.addNode(doc, channel, "copyright", COPYRIGHT);
XMLUtils.addNode(doc, channel, "pubDate", currentDate);
XMLUtils.addNode(doc, channel, "category", productTypeName);
XMLUtils.addNode(doc, channel, "generator", GENERATOR);
XMLUtils.addNode(doc, channel, "lastBuildDate", currentDate);
for (ProductResource productResource : resource.getProductResources())
{
String productLink = getBaseUri() + "product?productId="
+ productResource.getProductId();
Element item = XMLUtils.addNode(doc, channel, "item");
XMLUtils.addNode(doc, item, "title", productResource.getProductName());
XMLUtils.addNode(doc, item, "link", productLink);
XMLUtils.addNode(doc, item, "description", productResource
.getProductTypeName());
XMLUtils.addNode(doc, item, "guid", productLink);
Metadata metadata = productResource.getMetadataResource().getMetadata();
Date productReceivedTime = DateConvert.isoParse(metadata
.getMetadata("CAS.ProductReceivedTime"));
if (productReceivedTime != null)
{
XMLUtils.addNode(doc, item, "pubDate", dateFormatter
.format(productReceivedTime));
}
// Append additional tags defined in the configuration file.
if (configuration != null)
{
configuration.appendTags(metadata, doc, item);
}
}
XMLUtils.writeXmlToStream(doc, entityStream);
}
catch (ParserConfigurationException e)
{
String message = "Unable to create RSS XML document for RSS response.";
LOGGER.log(Level.WARNING, message, e);
throw new InternalServerErrorException(message);
}
catch (ParseException e)
{
String message = "Unable to create RSS XML document for RSS response.";
LOGGER.log(Level.WARNING, message, e);
throw new InternalServerErrorException(message);
}
}
}