/*
* 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.rss;
//JDK imports
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerException;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import java.util.HashMap;
import java.util.List;
import java.util.Date;
import java.util.Iterator;
import java.util.Map;
import java.util.logging.Logger;
import java.util.logging.Level;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import java.io.FileNotFoundException;
import java.net.MalformedURLException;
import java.net.URL;
import java.text.SimpleDateFormat;
import java.text.ParseException;
//OODT imports
import org.apache.oodt.cas.filemgr.structs.exceptions.CatalogException;
import org.apache.oodt.cas.filemgr.structs.exceptions.RepositoryManagerException;
import org.apache.oodt.cas.filemgr.structs.exceptions.ConnectionException;
import org.apache.oodt.cas.filemgr.structs.Product;
import org.apache.oodt.cas.filemgr.structs.ProductType;
import org.apache.oodt.cas.filemgr.structs.Reference;
import org.apache.oodt.cas.filemgr.system.XmlRpcFileManagerClient;
import org.apache.oodt.commons.xml.XMLUtils;
import org.apache.oodt.cas.metadata.Metadata;
import org.apache.oodt.commons.util.DateConvert;
/**
* A Servlet that supports the <a
* href="http://feedvalidator.org/docs/rss2.html">RSS 2.0</a> specification for
* delivering Product Feeds.
*
* @author mattmann
* @version $Revision$
*
*
*/
public class RSSProductServlet extends HttpServlet {
/* serial Version UID */
private static final long serialVersionUID = -465321738239885777L;
/* our client to the file manager */
private static XmlRpcFileManagerClient fm = null;
/* rss config */
private RSSConfig conf;
/* our log stream */
private Logger LOG = Logger.getLogger(RSSProductServlet.class.getName());
private static final Map NS_MAP = new HashMap();
public static final String COPYRIGHT_BOILER_PLATE = "Copyright 2010: Apache Software Foundation";
public static final String RSS_FORMAT_STR = "E, dd MMM yyyy HH:mm:ss z";
public static final SimpleDateFormat dateFormatter = new SimpleDateFormat(
RSS_FORMAT_STR);
static {
NS_MAP.put("cas", "http://oodt.jpl.nasa.gov/1.0/cas");
}
/**
* Default constructor.
*/
public RSSProductServlet() {
}
/**
* Initializes the servlet.
*/
public void init(ServletConfig config) throws ServletException {
super.init(config);
String fileManagerUrl = config.getServletContext().getInitParameter(
"filemgr.url");
if (fileManagerUrl == null) {
// try the default port
fileManagerUrl = "http://localhost:9000";
}
this.getFileManager(fileManagerUrl);
try {
this.conf = RSSUtils.initRSS(config);
} catch (FileNotFoundException e) {
throw new ServletException(e);
}
}
public void doGet(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, java.io.IOException {
doIt(req, resp);
}
public void doPost(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, java.io.IOException {
doIt(req, resp);
}
public void doIt(HttpServletRequest req, HttpServletResponse resp)
throws ServletException, java.io.IOException {
// need to know the type of product to get products for
String productTypeName = req.getParameter("channel");
String productTypeId = req.getParameter("id");
String topN = req.getParameter("topn");
ProductType type = null;
int top = 20;
if (topN != null) {
top = Integer.valueOf(topN).intValue();
}
String requestUrl = req.getRequestURL().toString();
String base = requestUrl.substring(0, requestUrl.lastIndexOf('/'));
Metadata channelMet = new Metadata();
channelMet.addMetadata("ProductType", productTypeName);
channelMet.addMetadata("ProductTypeId", productTypeId);
channelMet.addMetadata("TopN", String.valueOf(topN));
channelMet.addMetadata("BaseUrl", base);
List products = null;
try {
if (productTypeName.equals("ALL")) {
products = fm.getTopNProducts(top);
} else {
try {
type = fm.getProductTypeById(productTypeId);
} catch (RepositoryManagerException e) {
LOG.log(Level.SEVERE,
"Unable to obtain product type from product type id: ["
+ productTypeId + "]: Message: " + e.getMessage());
return;
}
products = fm.getTopNProducts(top, type);
}
} catch (CatalogException e) {
e.printStackTrace();
LOG
.log(Level.WARNING,
"Exception getting products from Catalog: Message: "
+ e.getMessage());
return;
}
if (products != null && products.size() > 0) {
String channelDesc = null;
if (!productTypeName.equals("ALL")) {
channelDesc = type.getDescription();
} else {
channelDesc = "ALL";
}
try {
DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
factory.setNamespaceAware(true);
Document doc = factory.newDocumentBuilder().newDocument();
Element rss = XMLUtils.addNode(doc, doc, "rss");
XMLUtils.addAttribute(doc, rss, "version", "2.0");
XMLUtils
.addAttribute(doc, rss, "xmlns:cas", (String) NS_MAP.get("cas"));
Element channel = XMLUtils.addNode(doc, rss, "channel");
XMLUtils.addNode(doc, channel, "title", productTypeName);
XMLUtils.addNode(doc, channel, "link", RSSUtils.getChannelLink(
this.conf.getChannelLink(), channelMet));
XMLUtils.addNode(doc, channel, "description", channelDesc);
String buildPubDate = dateFormatter.format(new Date());
XMLUtils.addNode(doc, channel, "language", "en-us");
XMLUtils.addNode(doc, channel, "copyright", COPYRIGHT_BOILER_PLATE);
XMLUtils.addNode(doc, channel, "pubDate", buildPubDate);
XMLUtils.addNode(doc, channel, "category", productTypeName);
XMLUtils.addNode(doc, channel, "generator", "CAS File Manager");
XMLUtils.addNode(doc, channel, "lastBuildDate", buildPubDate);
for (Iterator i = products.iterator(); i.hasNext();) {
Product p = (Product) i.next();
String productTypeIdStr = p.getProductType().getProductTypeId();
ProductType productType = null;
try {
productType = fm.getProductTypeById(productTypeIdStr);
} catch (RepositoryManagerException e) {
e.printStackTrace();
LOG.log(Level.SEVERE,
"Unable to obtain product type from product type id: ["
+ ((Product) products.get(0)).getProductType()
.getProductTypeId() + "]: Message: " + e.getMessage());
return;
}
p.setProductType(productType);
p.setProductReferences(safeGetProductReferences(p));
Element item = XMLUtils.addNode(doc, channel, "item");
XMLUtils.addNode(doc, item, "title", p.getProductName());
XMLUtils.addNode(doc, item, "description", p.getProductType()
.getName());
XMLUtils.addNode(doc, item, "link", base + "/data?productID="
+ p.getProductId());
Metadata m = this.safeGetMetadata(p);
String productReceivedTime = m.getMetadata("CAS.ProductReceivedTime");
Date receivedTime = null;
try {
receivedTime = DateConvert.isoParse(productReceivedTime);
} catch (ParseException ignore) {
}
if (receivedTime != null) {
XMLUtils.addNode(doc, item, "pubDate", dateFormatter
.format(receivedTime));
}
// add met field for FileSize for use in RSS envelope
if (p.getProductReferences() != null
&& p.getProductReferences().size() == 1) {
m.addMetadata("FileSize", String.valueOf(p.getProductReferences()
.get(0).getFileSize()));
}
// add additional elements from the RSSConfig
for (RSSTag tag : this.conf.getTags()) {
item.appendChild(RSSUtils.emitRSSTag(tag, m, doc, item));
}
}
DOMSource source = new DOMSource(doc);
TransformerFactory transFactory = TransformerFactory.newInstance();
Transformer transformer = transFactory.newTransformer();
transformer.setOutputProperty("indent", "yes");
StreamResult result = new StreamResult(resp.getOutputStream());
resp.setContentType("text/xml");
transformer.transform(source, result);
} catch (ParserConfigurationException e) {
throw new ServletException(e);
} catch (TransformerException e) {
throw new ServletException(e);
}
}
}
private Metadata safeGetMetadata(Product p) {
try {
return fm.getMetadata(p);
} catch (CatalogException ignore) {
ignore.printStackTrace();
return null;
}
}
private List<Reference> safeGetProductReferences(Product p) {
try {
return fm.getProductReferences(p);
} catch (CatalogException ignore) {
ignore.printStackTrace();
return null;
}
}
private void getFileManager(String fileManagerUrl) {
try {
this.fm = new XmlRpcFileManagerClient(new URL(fileManagerUrl));
} catch (MalformedURLException e) {
LOG.log(Level.SEVERE,
"Unable to initialize file manager url in RSS Servlet: [url="
+ fileManagerUrl + "], Message: " + e.getMessage());
} catch (ConnectionException e) {
LOG.log(Level.SEVERE,
"Unable to initialize file manager url in RSS Servlet: [url="
+ fileManagerUrl + "], Message: " + e.getMessage());
}
}
}