de.laures.cewolf.storage.AbstractSessionStorage Maven / Gradle / Ivy
/* ================================================================
* Cewolf : Chart enabling Web Objects Framework
* ================================================================
*
* Project Info: http://cewolf.sourceforge.net
* Project Lead: Guido Laures ([email protected]);
*
* (C) Copyright 2002, by Guido Laures
*
* 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.
*
* 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 de.laures.cewolf.storage;
import java.io.Serializable;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.jsp.PageContext;
import de.laures.cewolf.CewolfException;
import de.laures.cewolf.ChartImage;
import de.laures.cewolf.Storage;
import de.laures.cewolf.taglib.util.KeyGenerator;
/**
* @author glaures
*/
public abstract class AbstractSessionStorage implements Storage
{
// to keep track of object getting added and removed from the storage
protected volatile static int stored=0, removed=0;
/**
* @see de.laures.cewolf.Storage#storeChartImage(ChartImage, PageContext)
*/
public String storeChartImage( ChartImage cid, PageContext pageContext ) throws CewolfException
{
if ( contains(cid, pageContext) )
{
return getKey(cid);
}
final HttpSession session = pageContext.getSession();
//String key = getKey(cid);
return storeChartImage(cid, session);
}
/**
* @see de.laures.cewolf.Storage#getChartImage(String, javax.servlet.http.HttpServletRequest)
*/
public ChartImage getChartImage( String id, HttpServletRequest request )
{
HttpSession session = request.getSession();
return (ChartImage) session.getAttribute(id);
}
public boolean contains( ChartImage cid, PageContext pageContext )
{
return pageContext.getSession().getAttribute(getKey(cid)) != null;
}
public final String getKey( ChartImage cid )
{
return String.valueOf(KeyGenerator.generateKey((Serializable) cid));
}
protected String storeChartImage( ChartImage cid, HttpSession session ) throws CewolfException
{
final String sessionKey = getKey(cid);
synchronized (session)
{
session.setAttribute(sessionKey, getCacheObject(cid));
}
synchronized (AbstractSessionStorage.class) {
stored++;
//System.out.println("stored="+stored+", removed="+removed);
}
return sessionKey;
}
public String removeChartImage(String imgKey, HttpServletRequest request) throws CewolfException {
final HttpSession session = request.getSession();
if (session == null)
{
return imgKey;
}
return removeChartImage(imgKey, session);
}
protected String removeChartImage(String cid, HttpSession session) throws CewolfException {
synchronized (session) {
session.removeAttribute(cid);
}
synchronized (AbstractSessionStorage.class) {
removed++;
//System.out.println("stored="+stored+", removed="+removed);
}
return cid;
}
protected abstract Object getCacheObject( ChartImage cid ) throws CewolfException;
/**
* @see de.laures.cewolf.Storage#init(ServletContext)
*/
public void init( ServletContext servletContext ) throws CewolfException
{
}
}