001/*
002  GRANITE DATA SERVICES
003  Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004
005  This file is part of Granite Data Services.
006
007  Granite Data Services is free software; you can redistribute it and/or modify
008  it under the terms of the GNU Library General Public License as published by
009  the Free Software Foundation; either version 2 of the License, or (at your
010  option) any later version.
011
012  Granite Data Services is distributed in the hope that it will be useful, but
013  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014  FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015  for more details.
016
017  You should have received a copy of the GNU Library General Public License
018  along with this library; if not, see <http://www.gnu.org/licenses/>.
019*/
020
021package org.granite.clustering;
022
023import java.io.IOException;
024
025import javax.servlet.Filter;
026import javax.servlet.FilterChain;
027import javax.servlet.FilterConfig;
028import javax.servlet.ServletException;
029import javax.servlet.ServletRequest;
030import javax.servlet.ServletResponse;
031import javax.servlet.http.HttpServletRequest;
032
033/**
034 * This filter forces the creation of an HTTP session. Only useful in cluster
035 * environments when sticky-session is enabled, in order to ensure that a client
036 * will always use the same cluster node.
037 * 
038 * @author Franck WOLFF
039 */
040public class CreateSessionFilter implements Filter {
041
042        public void init(FilterConfig config) throws ServletException {
043        }
044
045        public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
046                ((HttpServletRequest)request).getSession(true);
047                chain.doFilter(request, response);
048        }
049
050        public void destroy() {
051        }
052}