/**
* The contents of this file are subject to the license and copyright
* detailed in the LICENSE and NOTICE files at the root of the source
* tree and available online at
*
* http://www.dspace.org/license/
*/
package org.dspace.app.webui.servlet;
import java.io.IOException;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Locale;
import java.util.Map;
import java.util.ResourceBundle;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.Transformer;
import javax.xml.transform.stream.StreamResult;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.TransformerException;
import org.w3c.dom.Document;
import org.apache.log4j.Logger;
import org.dspace.app.util.OpenSearch;
import org.dspace.app.util.SyndicationFeed;
import org.dspace.app.util.Util;
import org.dspace.authorize.AuthorizeException;
import org.dspace.content.Collection;
import org.dspace.content.Community;
import org.dspace.content.DSpaceObject;
import org.dspace.core.Context;
import org.dspace.core.LogManager;
import org.dspace.handle.HandleManager;
import org.dspace.search.DSQuery;
import org.dspace.search.QueryArgs;
import org.dspace.search.QueryResults;
import org.dspace.sort.SortOption;
/**
* Servlet for producing OpenSearch-compliant search results, and the
* OpenSearch description document.
* <p>
* OpenSearch is a specification for describing and advertising search-engines
* and their result formats. Commonly, RSS and Atom formats are used, which
* the current implementation supports, as is HTML (used directly in browsers).
* NB: this is baseline OpenSearch, no extensions currently supported.
* </p>
* <p>
* The value of the "scope" parameter should be absent (which means no
* scope restriction), or the handle of a community or collection, otherwise
* parameters exactly match those of the SearchServlet.
* </p>
*
* @author Richard Rodgers
*
*/
public class OpenSearchServlet extends DSpaceServlet
{
private static final long serialVersionUID = 1L;
private static String msgKey = "org.dspace.app.webui.servlet.FeedServlet";
/** log4j category */
private static Logger log = Logger.getLogger(OpenSearchServlet.class);
// locale-sensitive metadata labels
private Map<String, Map<String, String>> localeLabels = null;
public void init()
{
localeLabels = new HashMap<String, Map<String, String>>();
}
protected void doDSGet(Context context, HttpServletRequest request,
HttpServletResponse response) throws ServletException, IOException,
SQLException, AuthorizeException
{
// dispense with simple service document requests
String scope = request.getParameter("scope");
if (scope !=null && "".equals(scope))
{
scope = null;
}
String path = request.getPathInfo();
if (path != null && path.endsWith("description.xml"))
{
String svcDescrip = OpenSearch.getDescription(scope);
response.setContentType(OpenSearch.getContentType("opensearchdescription"));
response.setContentLength(svcDescrip.length());
response.getWriter().write(svcDescrip);
return;
}
// get enough request parameters to decide on action to take
String format = request.getParameter("format");
if (format == null || "".equals(format))
{
// default to atom
format = "atom";
}
// do some sanity checking
if (! OpenSearch.getFormats().contains(format))
{
response.sendError(HttpServletResponse.SC_BAD_REQUEST);
return;
}
// then the rest - we are processing the query
String query = request.getParameter("query");
int start = Util.getIntParameter(request, "start");
int rpp = Util.getIntParameter(request, "rpp");
int sort = Util.getIntParameter(request, "sort_by");
String order = request.getParameter("order");
String sortOrder = (order == null || order.length() == 0 || order.toLowerCase().startsWith("asc")) ?
SortOption.ASCENDING : SortOption.DESCENDING;
QueryArgs qArgs = new QueryArgs();
// can't start earlier than 0 in the results!
if (start < 0)
{
start = 0;
}
qArgs.setStart(start);
if (rpp > 0)
{
qArgs.setPageSize(rpp);
}
qArgs.setSortOrder(sortOrder);
if (sort > 0)
{
try
{
qArgs.setSortOption(SortOption.getSortOption(sort));
}
catch(Exception e)
{
// invalid sort id - do nothing
}
}
qArgs.setSortOrder(sortOrder);
// Ensure the query is non-null
if (query == null)
{
query = "";
}
// If there is a scope parameter, attempt to dereference it
// failure will only result in its being ignored
DSpaceObject container = (scope != null) ? HandleManager.resolveToObject(context, scope) : null;
// Build log information
String logInfo = "";
// get the start of the query results page
qArgs.setQuery(query);
// Perform the search
QueryResults qResults = null;
if (container == null)
{
qResults = DSQuery.doQuery(context, qArgs);
}
else if (container instanceof Collection)
{
logInfo = "collection_id=" + container.getID() + ",";
qResults = DSQuery.doQuery(context, qArgs, (Collection)container);
}
else if (container instanceof Community)
{
logInfo = "community_id=" + container.getID() + ",";
qResults = DSQuery.doQuery(context, qArgs, (Community)container);
}
else
{
throw new IllegalStateException("Invalid container for search context");
}
// now instantiate the results
DSpaceObject[] results = new DSpaceObject[qResults.getHitHandles().size()];
for (int i = 0; i < qResults.getHitHandles().size(); i++)
{
String myHandle = qResults.getHitHandles().get(i);
DSpaceObject dso = HandleManager.resolveToObject(context, myHandle);
if (dso == null)
{
throw new SQLException("Query \"" + query
+ "\" returned unresolvable handle: " + myHandle);
}
results[i] = dso;
}
// Log
log.info(LogManager.getHeader(context, "search", logInfo + "query=\"" + query + "\",results=(" + results.length + ")"));
// format and return results
Map<String, String> labelMap = getLabels(request);
Document resultsDoc = OpenSearch.getResultsDoc(format, query, qResults, container, results, labelMap);
try
{
Transformer xf = TransformerFactory.newInstance().newTransformer();
response.setContentType(OpenSearch.getContentType(format));
xf.transform(new DOMSource(resultsDoc), new StreamResult(response.getWriter()));
}
catch (TransformerException e)
{
log.error(e);
throw new ServletException(e.toString(), e);
}
}
private Map<String, String> getLabels(HttpServletRequest request)
{
// Get access to the localized resource bundle
Locale locale = request.getLocale();
Map<String, String> labelMap = localeLabels.get(locale.toString());
if (labelMap == null)
{
labelMap = getLocaleLabels(locale);
localeLabels.put(locale.toString(), labelMap);
}
return labelMap;
}
private Map<String, String> getLocaleLabels(Locale locale)
{
Map<String, String> labelMap = new HashMap<String, String>();
ResourceBundle labels = ResourceBundle.getBundle("Messages", locale);
labelMap.put(SyndicationFeed.MSG_UNTITLED, labels.getString(msgKey + ".notitle"));
labelMap.put(SyndicationFeed.MSG_LOGO_TITLE, labels.getString(msgKey + ".logo.title"));
labelMap.put(SyndicationFeed.MSG_FEED_DESCRIPTION, labels.getString(msgKey + ".general-feed.description"));
labelMap.put(SyndicationFeed.MSG_UITYPE, SyndicationFeed.UITYPE_JSPUI);
for (String selector : SyndicationFeed.getDescriptionSelectors())
{
labelMap.put("metadata." + selector, labels.getString(SyndicationFeed.MSG_METADATA + selector));
}
return labelMap;
}
}