/*
* File : $Source: /home/cvs/EbkModules/de.erzbistumkoeln.newsletter/src/de/erzbistumkoeln/newsletter/CmsNewsletterDateResourceComparator.java,v $
* Date : $Date: 2010-10-14 12:44:53 $
* Version: $Revision: 1.1 $
*
* This library is part of OpenCms -
* the Open Source Content Management System
*
* Copyright (c) 2002 - 2009 Alkacon Software GmbH (http://www.alkacon.com)
*
* This library 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 2.1 of the License, or (at your option) any later version.
*
* This library 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.
*
* For further information about Alkacon Software GmbH, please see the
* company website: http://www.alkacon.com
*
* For further information about OpenCms, please see the
* project website: http://www.opencms.org
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package com.alkacon.opencms.newsletter;
import org.opencms.file.CmsObject;
import org.opencms.file.CmsProperty;
import org.opencms.file.CmsResource;
import org.opencms.file.collectors.CmsDateResourceComparator;
import org.opencms.main.CmsException;
import org.opencms.util.CmsStringUtil;
import org.opencms.util.CmsUUID;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Comparator for sorting newsletter resource objects based on dates.<p>
*
* Serves as {@link java.util.Comparator} for resources and as comparator key for the resource
* at the same time. Uses lazy initializing of comparator keys for a resource.<p>
*
* @author Andreas Zahner
*
* @version $Revision: 1.1 $
*
* @since 7.9.2
*/
public class CmsNewsletterDateResourceComparator implements Comparator<CmsResource> {
/** The date sort order. */
private boolean m_asc;
/** The current OpenCms user context. */
private CmsObject m_cms;
/** The date of this comparator key. */
private long m_date;
/** The internal map of comparator keys. */
private Map<CmsUUID, CmsNewsletterDateResourceComparator> m_keys;
/**
* Creates a new instance of this comparator key.<p>
*
* @param cms the current OpenCms user context
* @param asc if true, the date sort order is ascending, otherwise descending
*/
public CmsNewsletterDateResourceComparator(CmsObject cms, boolean asc) {
m_cms = cms;
m_asc = asc;
m_keys = new HashMap<CmsUUID, CmsNewsletterDateResourceComparator>();
}
/**
* Creates a new, empty instance of this comparator key, used for the calculated map valued.<p>
*/
private CmsNewsletterDateResourceComparator() {
// NOOP
}
/**
* Calculates the date to use for comparison of this resource based on the given date identifiers.<p>
*
* @param cms the current OpenCms user context
* @param resource the resource to create the key for
* @param defaultValue the default value to use in case no value can be calculated
*
* @return the calculated date
*
* @see CmsDateResourceComparator for a description about how the date identifieres are used
*/
public static long calculateDate(CmsObject cms, CmsResource resource, long defaultValue) {
long result = 0;
String propValue = "";
try {
propValue = cms.readPropertyObject(resource, CmsNewsletterManager.PROPERTY_NEWSLETTER_DATA, false).getValue();
} catch (CmsException e) {
// failed to read the property, ignore
}
if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(propValue)) {
// there is a value set for the property
List<String> valueParts = CmsStringUtil.splitAsList(propValue, CmsProperty.VALUE_LIST_DELIMITER, true);
try {
result = Long.parseLong(valueParts.get(0));
resource.setDateReleased(result);
} catch (NumberFormatException e) {
// ignore, the default value is used
}
}
if (result == 0) {
// if nothing else was found, use default
result = defaultValue;
}
return result;
}
/**
* Creates a new instance of this comparator key.<p>
*
* @param cms the current OpenCms user context
* @param resource the resource to create the key for
*
* @return a new instance of this comparator key
*/
private static CmsNewsletterDateResourceComparator create(CmsObject cms, CmsResource resource) {
CmsNewsletterDateResourceComparator result = new CmsNewsletterDateResourceComparator();
result.m_date = calculateDate(cms, resource, resource.getDateLastModified());
return result;
}
/**
* Compares {@link CmsResource} objects based on the date
* found in the {@link CmsNewsletterManager#PROPERTY_NEWSLETTER_DATA} property.<p>
*
* @param res0 the first resource to be compared
* @param res1 the second resource to be compared
*
* @return a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.
*
* @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
*/
public int compare(CmsResource res0, CmsResource res1) {
if (res0 == res1) {
return 0;
}
CmsNewsletterDateResourceComparator key0 = m_keys.get(res0.getStructureId());
CmsNewsletterDateResourceComparator key1 = m_keys.get(res1.getStructureId());
if (key0 == null) {
// initialize key if null
key0 = CmsNewsletterDateResourceComparator.create(m_cms, res0);
m_keys.put(res0.getStructureId(), key0);
}
if (key1 == null) {
// initialize key if null
key1 = CmsNewsletterDateResourceComparator.create(m_cms, res1);
m_keys.put(res1.getStructureId(), key1);
}
if (m_asc) {
// sort in ascending order
if (key0.m_date > key1.m_date) {
return 1;
}
if (key0.m_date < key1.m_date) {
return -1;
}
} else {
// sort in descending order
if (key0.m_date > key1.m_date) {
return -1;
}
if (key0.m_date < key1.m_date) {
return 1;
}
}
return 0;
}
/**
* Returns the date of this resource comparator key.<p>
*
* @return the date of this resource comparator key
*/
public long getDate() {
return m_date;
}
}