bindsessionsfilter.java

web版的SVN客户端

/*
 * $Id: BindSessionsFilter.java,v 1.2 2004/10/26 14:44:13 dobisekm Exp $
 *
 * Copyright (C) 2000-2004 Polarion Software
 * All rights reserved.
 * Email: [e-mail]
 *
 *
 * Copyright (C) 2000-2004 Polarion Software
 * All Rights Reserved.  No use, copying or distribution of this
 * work may be made except in accordance with a valid license
 * agreement from Polarion Software  This notice must be
 * included on all copies, modifications and derivatives of this
 * work.
 *
 * Polarion Software MAKES NO REPRESENTATIONS OR WARRANTIES 
 * ABOUT THE SUITABILITY OF THE SOFTWARE, EITHER EXPRESSED OR IMPLIED, 
 * INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT. Polarion Software
 * SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT
 * OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 *
 */
package org.polarion.svnwebclient.authorization.impl;

import java.io.IOException;
import java.net.InetAddress;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;

import javax.security.auth.Subject;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpSessionBindingEvent;
import javax.servlet.http.HttpSessionBindingListener;

import com.polarion.portal.tomcat.SubjectExchange;
import com.polarion.subterra.base.SubterraURI;
import com.polarion.subterra.server.core.SubterraServerCorePlugin;
import com.polarion.subterra.server.core.cli.locate.ISubterraClient;
import com.polarion.subterra.server.core.cli.locate.SubterraClientLocator;
import com.polarion.subterra.server.core.cli.session.IClientSession;
import com.polarion.subterra.server.core.cli.session.IClientSessionManager;
import com.polarion.subterra.server.core.session.ISession;
import com.polarion.subterra.server.core.session.ISessionManager;
import com.polarion.core.util.MeasureTime;
import com.polarion.core.util.logging.Logger;

/**
 * This filter tries to bind correct subterra session to each http session - the subterra session is stored in
 * httpSession attributes and is restored for every request.
 *
 * @author  <A HREF="mailto:[e-mail]">Michal Dobisek</A>, Polarion Software
 * @version $Revision: 1.2 $ $Date: 2004/10/26 14:44:13 $
 */
public class BindSessionsFilter implements Filter {
    
    private static Logger log = Logger.getLogger(BindSessionsFilter.class);
    
    public static final String SUBTERRA_SESSION = "BindSessionsFilter.SubterraSession";
    
    private ISubterraClient subterraClient = null;
    private IClientSessionManager cliSessMgr = null;
    private ISessionManager sessMgr = null;
    
    /* @see javax.servlet.Filter#init(javax.servlet.FilterConfig) */
    public void init(FilterConfig config) throws ServletException {
        try {
            cliSessMgr = (IClientSessionManager) SubterraServerCorePlugin.getDefault()
                    .getServerContext().getServiceManager()
                    .getService(IClientSessionManager.WELLKNOWN_ID);
            
            sessMgr = SubterraServerCorePlugin.getDefault().getServerContext().getSessionManager();
            
            // TODO There might be a better way to find subterraClient
            SubterraURI localhostURI = cliSessMgr.getNamingURI();
            subterraClient = SubterraClientLocator.getInstance().locateClient(localhostURI);
            
        } catch(Exception e) {
            log.error("FATAL ERROR: Unable to initialize SessionBindingfilter!", e);
            throw new ServletException("Unable to initialize SessionBindingfilter!", e);
        }
    }
    
    private static Object lock = new Object();
    
    private static final ThreadLocal currentSessionId = new ThreadLocal();

    /* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain) */
    public void doFilter(final ServletRequest request, final ServletResponse response, final FilterChain chain) throws IOException, ServletException {
        
        MeasureTime mt = null;
        if(log.isDebugEnabled()) {
            mt = new MeasureTime();
            HttpServletRequest htrq = (HttpServletRequest) request;
            log.debug("REQUEST PROCESSING STARTED, "+htrq.getRequestURL());
        }
        
        HttpSession sessionHttp = ((HttpServletRequest) request).getSession();
        currentSessionId.set(sessionHttp.getId());
        
        if (log.isDebugEnabled()) {
            log.debug("doFilter - httpSession: "+sessionHttp.getId());
        }

        SessionInfo sessNfo = null;
        IClientSession origSession = null;
        
        Subject subject = null;
        try {
            // Is it OK to synchronize on session?
            synchronized(lock) {
                sessNfo = (SessionInfo) sessionHttp.getAttribute(SUBTERRA_SESSION);                
                
                origSession = null;
                if(sessNfo != null && sessNfo.session != null) {
                    if (log.isDebugEnabled()) {
                        log.debug("doFilter - binding session "+sessNfo.session);
                    }
                    // Check here - if http session contains a subterra session, then
                    // use the subterra session     
                    subterraClient.setCurrentSession(sessNfo.session);
                    origSession = sessNfo.session;
                    
                    if(origSession != null) {
	                    // We can't get the subject from the client session
	                    ISession session = sessMgr.convertToServerSession(origSession);
	                    if ((session != null) && !session.isClosed()) {
	                        subject = session.getSubject();
                            SubjectExchange.setSessionSubject(sessionHttp.getId(), subject);
	                    }
                    }

                } else {
                    subject = CredentialsManager.getSubject((HttpServletRequest) request);
                    sessMgr = SubterraServerCorePlugin.getDefault().getServerContext().getSessionManager();
                    sessMgr.login(false, subject, "SVNWebClient Thread", "", InetAddress.getLocalHost());
                }
            }
        } catch(Exception e) {
            log.error("Some exception in session binding INIT.", e);
        }
                
        try {
            Subject.doAs(subject, new PrivilegedExceptionAction() {
                public Object run() throws Exception {
                    // *** Process the request
                    chain.doFilter(request, response);
                    return null;
                }
            });
        } catch(PrivilegedActionException e) {
            throw new ServletException("", e);
        } finally {
            currentSessionId.set(null);
            try {
                IClientSession session = subterraClient.getCurrentSession();
                
                synchronized(lock) {
                    sessNfo = (SessionInfo) sessionHttp.getAttribute(SUBTERRA_SESSION);
                    
                    // Session info could have been removed by
                    // the login action
                    if(sessNfo == null) {
                        if (log.isDebugEnabled()) {
                            log.debug("doFilter - creating session info");
                        }
                        sessNfo = new SessionInfo(null);
                        sessionHttp.setAttribute(SUBTERRA_SESSION, sessNfo);                
                    }
                    
                    if((session == null && origSession != null) 
                            || (session != null && !session.equals(origSession))) {
                        if (log.isDebugEnabled()) {
                            log.debug("doFilter - session changes, storing. New session "+session);
                        }
                        
                        sessNfo.session = session;
                    }
                }
                
                subterraClient.setCurrentSession(null);
            } catch(Exception e) {
                log.error("Some exception in session binding FINALIZE.", e);
            }
            
            if(log.isDebugEnabled()) {
                HttpServletRequest htrq = (HttpServletRequest) request;
                log.debug("REQUEST PROCESSING DONE"+mt+" "+htrq.getRequestURL());
            }
        }
    }
    
    /**
     * Can be called from within a request only. Otherwise returns null.
     * @return
     */
    public static String getSessionId() {
        return (String) currentSessionId.get();
    }

    /* @see javax.servlet.Filter#destroy() */
    public void destroy() {
        // ignore
    }
    
    public class SessionInfo implements HttpSessionBindingListener {
        
        public IClientSession session;
        
        public SessionInfo(IClientSession session) {
            this.session = session;
        }

        /* @see javax.servlet.http.HttpSessionBindingListener#valueBound(javax.servlet.http.HttpSessionBindingEvent) */
        public void valueBound(HttpSessionBindingEvent event) {
            // ignore              
        }

        /* @see javax.servlet.http.HttpSessionBindingListener#valueUnbound(javax.servlet.http.HttpSessionBindingEvent) */
        public void valueUnbound(HttpSessionBindingEvent event) {
            try {
                if (log.isDebugEnabled()) {
                    log.debug("valueUnbound - removing session info. httpSession: "+event.getSession().getId());
                }
                
                // Remove the binding
                SubjectExchange.removeSessionSubject(event.getSession().getId());
                
                if(session == null) {
                    return;
                }
                
                // close the SubterraSession
                subterraClient.setCurrentSession(session);
                // prevention of closing already closed session
                if (subterraClient.getCurrentSession() != null) {
                    cliSessMgr.logout();
                }
            } catch (Exception ee) {
                log.error("valueUnbound() - Got exception while closing SubterraSession. ", ee);
            }
        }
    }


}

/*
 * $Log: BindSessionsFilter.java,v $
 * Revision 1.2  2004/10/26 14:44:13  dobisekm
 * RefProxy dependency removed
 *
 * Revision 1.1  2004/09/22 13:18:44  dobisekm
 * adding
 *
 */