ImportPublish.java

/* Copyright (2007-2012) Schibsted ASA
 *   This file is part of Possom.
 *
 *   Possom is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU Lesser General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   Possom is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU Lesser General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public License
 *   along with Possom.  If not, see <http://www.gnu.org/licenses/>.
 *
 * ImportPublish.java
 *
 * Created on 12 March 2007, 15:38
 *
 */

package no.sesat.search.view;

import com.opensymphony.oscache.base.NeedsRefreshException;
import com.opensymphony.oscache.general.GeneralCacheAdministrator;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.StringReader;
import java.net.URL;
import java.util.Properties;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import no.sesat.search.datamodel.DataModel;
import no.sesat.search.http.HTTPClient;
import no.sesat.search.site.config.SiteConfiguration;
import org.w3c.dom.Document;
import org.xml.sax.SAXException;
import org.xml.sax.InputSource;
import org.apache.log4j.Logger;

/**
 * General support to import page fragments from publishing system.
 * Caches content on a one minute basis to reduce outbound socket connections.
 *
 *
 * @version <tt>$Id$</tt>
 */
public final class ImportPublish {

    // Constants -----------------------------------------------------

    private static final GeneralCacheAdministrator CACHE = new GeneralCacheAdministrator();
    private static final int REFRESH_PERIOD = 60; // one minute
    private static final int CACHE_CAPACITY = 1000;

    private static final Logger LOG = Logger.getLogger(ImportPublish.class);
    private static final Logger DUMP = Logger.getLogger("no.sesat.search.Dump");

    // Attributes ----------------------------------------------------

    // Static --------------------------------------------------------

    static{
        CACHE.setCacheCapacity(CACHE_CAPACITY);
    }

    /**
     *
     * @param page
     * @param datamodel
     * @return
     * @throws java.io.IOException
     */
    public static String importPage(
            final String page,
            final DataModel datamodel) throws IOException{

        final Properties props = datamodel.getSite().getSiteConfiguration().getProperties();

        final String fileExtension = page.endsWith(".xml") ? "" : ".html";

        final URL u = new URL(props.getProperty(SiteConfiguration.PUBLISH_SYSTEM_URL) + page + fileExtension);
        final String physicalHost = props.getProperty(SiteConfiguration.PUBLISH_PHYSICAL_HOST);
        final String cacheKey = '[' + physicalHost + ']' + u.toString();

        String content = "";
        try{
            content = (String) CACHE.getFromCache(cacheKey, REFRESH_PERIOD);
            LOG.debug("found cached content for " + page);

        } catch (NeedsRefreshException nre) {

            boolean updatedCache = false;
            final HTTPClient client = HTTPClient.instance(u, physicalHost);

            try{
                final BufferedReader reader = client.getBufferedReader("");
                final StringBuilder builder = new StringBuilder();

                for(String line = reader.readLine(); line != null; line = reader.readLine()){
                    builder.append(line);
                    builder.append('\n');
                }
                content = builder.toString();
                CACHE.putInCache(cacheKey, content);
                updatedCache = true;

                LOG.debug("new content for " + page);

            }catch(IOException ioe){
                content = (String) nre.getCacheContent();
                throw client.interceptIOException(ioe);

            }finally{
                if(!updatedCache){
                    CACHE.cancelUpdate(cacheKey);
                }
            }
        }
        if(DUMP.isDebugEnabled()){ DUMP.debug("Content for " + page + " is \n" + content); }

        return content;
    }

    /**
     *
     * @param page
     * @param datamodel
     * @return
     * @throws java.io.IOException
     * @throws javax.xml.parsers.ParserConfigurationException
     * @throws org.xml.sax.SAXException
     */
    public static Document importXml(
            final String page,
            final DataModel datamodel) throws IOException, ParserConfigurationException, SAXException{

        final DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
        final DocumentBuilder builder = factory.newDocumentBuilder();
        try {
            return builder.parse(new InputSource(new StringReader(importPage(page, datamodel))));
        } catch (SAXException e) {
            LOG.error("XML Parse exception. ", e);
            return builder.newDocument();
        }
    }

    // Constructors --------------------------------------------------

    /** Creates a new instance of NewClass */
    private ImportPublish() {
    }

    // Public --------------------------------------------------------


    // Package protected ---------------------------------------------

    // Protected -----------------------------------------------------

    // Private -------------------------------------------------------

    // Inner classes -------------------------------------------------

}