Jetty example source code file (WadiSessionManager.java)

This example Jetty source code file (WadiSessionManager.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Jetty tags/keywords

assertionerror, clusteredsession, clusteredsession, http, iterator, map, network, request, response, servicespacename, servlet, session, sessionalreadyexistsexception, sessionlistener, sessionlistener, util, wadisessionadaptor, wadisessionadaptor, wadisessionmanager, wadisessionmanager

The Jetty WadiSessionManager.java source code

package org.mortbay.jetty.servlet.wadi;

import java.net.URI;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.codehaus.wadi.aop.replication.AOPStackContext;
import org.codehaus.wadi.core.assembler.StackContext;
import org.codehaus.wadi.core.manager.Manager;
import org.codehaus.wadi.core.manager.SessionAlreadyExistException;
import org.codehaus.wadi.core.manager.SessionMonitor;
import org.codehaus.wadi.core.store.Store;
import org.codehaus.wadi.replication.strategy.BackingStrategyFactory;
import org.codehaus.wadi.replication.strategy.RoundRobinBackingStrategyFactory;
import org.codehaus.wadi.servicespace.ServiceSpace;
import org.codehaus.wadi.servicespace.ServiceSpaceName;
import org.mortbay.jetty.servlet.AbstractSessionManager;
import org.mortbay.jetty.servlet.HashSessionIdManager;

import edu.emory.mathcs.backport.java.util.concurrent.CopyOnWriteArrayList;

public class WadiSessionManager extends AbstractSessionManager
{
    private final Map<String, ClusteredSession> _idToSession = new HashMap();
    private BackingStrategyFactory _backingStrategyFactory;
    private WadiCluster _wadiCluster;
    private CopyOnWriteArrayList _listeners;
    private Manager _manager;
    private SessionMonitor _sessionMonitor;
    private ServiceSpace _serviceSpace;
    private int _nbReplica;
    private int _numPartitions;
    private int _sweepInterval;
    private final boolean _enableReplication;
    private final boolean _deltaReplication;
    private Store _sharedStore;
    
    public WadiSessionManager(WadiCluster wadiCluster, int numPartitions, int sweepInterval)
    {
        this(wadiCluster, 0, numPartitions, sweepInterval, false, false);
    }

    public WadiSessionManager(WadiCluster wadiCluster, int nbReplica, int numPartitions, int sweepInterval)
    {
        this(wadiCluster, nbReplica, numPartitions, sweepInterval, true, false);
    }
    
    /**
     * Constructs a session manager attached to the provided cluster. 
     * 
     * @param wadiCluster cluster this session manager is attached to.
     * @param nbReplica number of replicas to be maintained for each sessions managed by this session manager. When a 
     * session is created or updated, it is replicated to a configurable number of other nodes.
     * @param numPartitions WADI maintains a distributed and indexed look-up map tracking HttpSession locations. 
     * numPartitions is the number of indexes of this look-up map. A standard number of partitions is 24.
     * @param sweepInterval number of seconds between the execution of HttpSession eviction policies. In other words, 
     * it is how often HttpSessions are scanned to identify and invalidate timed out sessions
     * @param enableReplication if true, then sessions are replicated to other nodes. The number of replicas is 
     * configured by nbReplica.
     */
    public WadiSessionManager(WadiCluster wadiCluster,
            int nbReplica,
            int numPartitions,
            int sweepInterval,
            boolean enableReplication,
            boolean deltaReplication)
    {
        _wadiCluster = wadiCluster;
        _nbReplica = nbReplica;
        _numPartitions = numPartitions;
        _sweepInterval = sweepInterval;
        _enableReplication = enableReplication;
        _deltaReplication = deltaReplication;
        
        _listeners = new CopyOnWriteArrayList();

        HashSessionIdManager sessionIdManager = new HashSessionIdManager();
        sessionIdManager.setWorkerName(wadiCluster.getNodeName());
        setIdManager(sessionIdManager);

        registerListener(new MigrationListener());
    }

    public Store getSharedStore()
    {
        return _sharedStore;
    }

    public void setSharedStore(Store store)
    {
        _sharedStore = store;
    }

    public void doStart() throws Exception
    {
        super.doStart();
        
        _backingStrategyFactory = new RoundRobinBackingStrategyFactory(_nbReplica);
        
        ServiceSpaceName serviceSpaceName = new ServiceSpaceName(new URI(_context.getContextPath() + "/"));
        
        StackContext stackContext;
        if (_deltaReplication) {
            stackContext = new AOPStackContext(Thread.currentThread().getContextClassLoader(),
                serviceSpaceName,
                _wadiCluster.getDispatcher(),
                _dftMaxIdleSecs,
                _numPartitions,
                _sweepInterval,
                _backingStrategyFactory);
        } else {
            stackContext = new StackContext(Thread.currentThread().getContextClassLoader(),
                serviceSpaceName,
                _wadiCluster.getDispatcher(),
                _dftMaxIdleSecs,
                _numPartitions,
                _sweepInterval,
                _backingStrategyFactory);
            
        }
        stackContext.setSharedStore(_sharedStore);
        stackContext.setDisableReplication(!_enableReplication);
        stackContext.build();

        _serviceSpace = stackContext.getServiceSpace();
        _manager = stackContext.getManager();

        _sessionMonitor = stackContext.getSessionMonitor();
        _sessionMonitor.addSessionListener(new SessionListenerAdapter());

        _serviceSpace.start();
    }

    public void doStop() throws Exception
    {
        _serviceSpace.stop();
        super.doStop();
    }

    public Manager getClusteredManager()
    {
        return _manager;
    }

    public WadiSession createSession(String sessionId) throws SessionAlreadyExistsException
    {
        org.codehaus.wadi.core.session.Session session;
        try
        {
            session = _manager.createWithName(sessionId);
        }
        catch (SessionAlreadyExistException e)
        {
            throw new SessionAlreadyExistsException(sessionId);
        }
        return new WadiSessionAdaptor(session);
    }

    public void registerListener(SessionListener listener)
    {
        _listeners.add(listener);
    }

    public void unregisterListener(SessionListener listener)
    {
        _listeners.remove(listener);
    }

    private void notifyInboundSessionMigration(org.codehaus.wadi.core.session.Session session)
    {
        for (Iterator iter = _listeners.iterator(); iter.hasNext();)
        {
            SessionListener listener = (SessionListener) iter.next();
            listener.notifyInboundSessionMigration(new WadiSessionAdaptor(session));
        }
    }

    private void notifyOutboundSessionMigration(org.codehaus.wadi.core.session.Session session)
    {
        for (Iterator iter = _listeners.iterator(); iter.hasNext();)
        {
            SessionListener listener = (SessionListener) iter.next();
            listener.notifyOutboundSessionMigration(new WadiSessionAdaptor(session));
        }
    }

    private void notifySessionDestruction(org.codehaus.wadi.core.session.Session session)
    {
        for (Iterator iter = _listeners.iterator(); iter.hasNext();)
        {
            SessionListener listener = (SessionListener) iter.next();
            listener.notifySessionDestruction(new WadiSessionAdaptor(session));
        }
    }

    private class SessionListenerAdapter implements org.codehaus.wadi.core.manager.SessionListener
    {

        public void onSessionCreation(org.codehaus.wadi.core.session.Session session) {
        }

        public void onSessionDestruction(org.codehaus.wadi.core.session.Session session) {
            notifySessionDestruction(session);
        }

        public void onInboundSessionMigration(org.codehaus.wadi.core.session.Session session) {
            notifyInboundSessionMigration(session);
        }
        
        public void onOutbountSessionMigration(org.codehaus.wadi.core.session.Session session) {
            notifyOutboundSessionMigration(session);
        }
        
    }

    protected Session newSession(HttpServletRequest request)
    {
        return new ClusteredSession(request);
    }

    public void complete(HttpSession session)
    {
        ClusteredSession clusteredSession = (ClusteredSession) session;
        clusteredSession.session.onEndAccess();
    }

    protected void addSession(Session session)
    {
        ClusteredSession clusteredSession = (ClusteredSession) session;
        synchronized (_idToSession)
        {
            _idToSession.put(clusteredSession.getClusterId(), clusteredSession);
        }
    }

    protected void removeSession(String idInCluster)
    {
        // Let MigrationListener handle session removal
    }

    public Session getSession(String idInCluster)
    {
        synchronized (_idToSession)
        {
            return _idToSession.get(idInCluster);
        }
    }

    public int getSessions()
    {
        synchronized (_idToSession)
        {
            return _idToSession.size();
        }
    }

    public Map getSessionMap()
    {
        throw new AssertionError("getSessionMap is never used.");
    }

    protected void invalidateSessions()
    {
    }

    private class MigrationListener implements SessionListener
    {

        public void notifyInboundSessionMigration(WadiSession session)
        {
            addSession(new ClusteredSession(session), false);
        }

        public void notifyOutboundSessionMigration(WadiSession session)
        {
            ClusteredSession clusteredSession = getClusteredSession(session);
            removeSession(clusteredSession, false);
        }

        public void notifySessionDestruction(WadiSession session)
        {
            ClusteredSession clusteredSession = getClusteredSession(session);
            removeSession(clusteredSession, true);
        }

        private ClusteredSession getClusteredSession(WadiSession session) throws AssertionError
        {
            ClusteredSession clusteredSession;
            synchronized (_idToSession)
            {
                clusteredSession = _idToSession.remove(session.getSessionId());
            }
            if (null == clusteredSession)
            {
                throw new AssertionError("Session [" + session + "] is undefined");
            }
            return clusteredSession;
        }

    }

    public class ClusteredSession extends Session
    {
        private final WadiSession session;

        protected ClusteredSession(HttpServletRequest request)
        {
            super(request);
            try
            {
                this.session = createSession(getClusterId());
            }
            catch (SessionAlreadyExistsException e)
            {
                throw (IllegalStateException) new IllegalStateException().initCause(e);
            }
            initValues();
        }

        protected ClusteredSession(WadiSession session)
        {
            super(System.currentTimeMillis(), session.getSessionId());
            this.session = session;
            initValues();
        }

        protected Map newAttributeMap()
        {
            return session.getState();
        }

        protected String getClusterId()
        {
            return super.getClusterId();
        }

        public void invalidate() throws IllegalStateException
        {
            super.doInvalidate();
            session.release();
        }
    }

}