/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.catalina;
import java.beans.PropertyChangeListener;
import java.io.IOException;
/**
* A <b>Manager</b> manages the pool of Sessions that are associated with a
* particular Container. Different Manager implementations may support
* value-added features such as the persistent storage of session data,
* as well as migrating sessions for distributable web applications.
* <p>
* In order for a <code>Manager</code> implementation to successfully operate
* with a <code>Context</code> implementation that implements reloading, it
* must obey the following constraints:
* <ul>
* <li>Must implement <code>Lifecycle</code> so that the Context can indicate
* that a restart is required.
* <li>Must allow a call to <code>stop()</code> to be followed by a call to
* <code>start()</code> on the same <code>Manager</code> instance.
* </ul>
*
* @author Craig R. McClanahan
*
*/
public interface Manager {
// ------------------------------------------------------------- Properties
/**
* Return the Container with which this Manager is associated.
*/
public Container getContainer();
/**
* Set the Container with which this Manager is associated. The Container
* must be set to a non-null value before the Manager is first used.
* Multiple calls to this method before first use are permitted. Once the
* Manager has been used, this method may not be used to change the
* Container (including setting a {@code null} value) that the Manager is
* associated with.
*
* @param container The newly associated Container
*/
public void setContainer(Container container);
/**
* Return the distributable flag for the sessions supported by
* this Manager.
*
* @deprecated Ignored. {@link Context#getDistributable()} always takes
* precedence. Will be removed in Tomcat 9.0.x.
*/
@Deprecated
public boolean getDistributable();
/**
* Set the distributable flag for the sessions supported by this
* Manager. If this flag is set, all user data objects added to
* sessions associated with this manager must implement Serializable.
*
* @param distributable The new distributable flag
*
* @deprecated Ignored. {@link Context#getDistributable()} always takes
* precedence. Will be removed in Tomcat 9.0.x.
*/
@Deprecated
public void setDistributable(boolean distributable);
/**
* Return descriptive information about this Manager implementation and
* the corresponding version number, in the format
* <code><description>/<version></code>.
*/
public String getInfo();
/**
* Return the default maximum inactive interval (in seconds)
* for Sessions created by this Manager.
*
* @deprecated Ignored. {@link Context#getSessionTimeout()} always takes
* precedence. Will be removed in Tomcat 9.0.x.
*/
@Deprecated
public int getMaxInactiveInterval();
/**
* Set the default maximum inactive interval (in seconds)
* for Sessions created by this Manager.
*
* @param interval The new default value
*
* @deprecated Ignored. {@link Context#getSessionTimeout()} always takes
* precedence. Will be removed in Tomcat 9.0.x.
*/
@Deprecated
public void setMaxInactiveInterval(int interval);
/**
* Gets the session id length (in bytes) of Sessions created by
* this Manager.
*
* @return The session id length
*/
public int getSessionIdLength();
/**
* Sets the session id length (in bytes) for Sessions created by this
* Manager.
*
* @param idLength The session id length
*/
public void setSessionIdLength(int idLength);
/**
* Returns the total number of sessions created by this manager.
*
* @return Total number of sessions created by this manager.
*/
public int getSessionCounter();
/**
* Sets the total number of sessions created by this manager.
*
* @param sessionCounter Total number of sessions created by this manager.
*/
public void setSessionCounter(int sessionCounter);
/**
* Gets the maximum number of sessions that have been active at the same
* time.
*
* @return Maximum number of sessions that have been active at the same
* time
*/
public int getMaxActive();
/**
* (Re)sets the maximum number of sessions that have been active at the
* same time.
*
* @param maxActive Maximum number of sessions that have been active at
* the same time.
*/
public void setMaxActive(int maxActive);
/**
* Gets the number of currently active sessions.
*
* @return Number of currently active sessions
*/
public int getActiveSessions();
/**
* Gets the number of sessions that have expired.
*
* @return Number of sessions that have expired
*/
public int getExpiredSessions();
/**
* Sets the number of sessions that have expired.
*
* @param expiredSessions Number of sessions that have expired
*/
public void setExpiredSessions(int expiredSessions);
/**
* Gets the number of sessions that were not created because the maximum
* number of active sessions was reached.
*
* @return Number of rejected sessions
*/
public int getRejectedSessions();
/**
* Sets the number of sessions that were not created because the maximum
* number of active sessions was reached.
*
* @param rejectedSessions Number of rejected sessions
*/
public void setRejectedSessions(int rejectedSessions);
/**
* Gets the longest time (in seconds) that an expired session had been
* alive.
*
* @return Longest time (in seconds) that an expired session had been
* alive.
*/
public int getSessionMaxAliveTime();
/**
* Sets the longest time (in seconds) that an expired session had been
* alive.
*
* @param sessionMaxAliveTime Longest time (in seconds) that an expired
* session had been alive.
*/
public void setSessionMaxAliveTime(int sessionMaxAliveTime);
/**
* Gets the average time (in seconds) that expired sessions had been
* alive.
*
* @return Average time (in seconds) that expired sessions had been
* alive.
*/
public int getSessionAverageAliveTime();
/**
* Sets the average time (in seconds) that expired sessions had been
* alive.
*
* @param sessionAverageAliveTime Average time (in seconds) that expired
* sessions had been alive.
*/
public void setSessionAverageAliveTime(int sessionAverageAliveTime);
// --------------------------------------------------------- Public Methods
/**
* Add this Session to the set of active Sessions for this Manager.
*
* @param session Session to be added
*/
public void add(Session session);
/**
* Add a property change listener to this component.
*
* @param listener The listener to add
*/
public void addPropertyChangeListener(PropertyChangeListener listener);
/**
* Change the session ID of the current session to a new randomly generated
* session ID.
*
* @param session The session to change the session ID for
*/
public void changeSessionId(Session session);
/**
* Get a session from the recycled ones or create a new empty one.
* The PersistentManager manager does not need to create session data
* because it reads it from the Store.
*/
public Session createEmptySession();
/**
* Construct and return a new session object, based on the default
* settings specified by this Manager's properties. The session
* id will be assigned by this method, and available via the getId()
* method of the returned session. If a new session cannot be created
* for any reason, return <code>null</code>.
*
* @exception IllegalStateException if a new session cannot be
* instantiated for any reason
* @deprecated
*/
@Deprecated
public Session createSession();
/**
* Construct and return a new session object, based on the default
* settings specified by this Manager's properties. The session
* id specified will be used as the session id.
* If a new session cannot be created for any reason, return
* <code>null</code>.
*
* @param sessionId The session id which should be used to create the
* new session; if <code>null</code>, the session
* id will be assigned by this method, and available via the getId()
* method of the returned session.
* @exception IllegalStateException if a new session cannot be
* instantiated for any reason
*/
public Session createSession(String sessionId);
/**
* Return the active Session, associated with this Manager, with the
* specified session id (if any); otherwise return <code>null</code>.
*
* @param id The session id for the session to be returned
*
* @exception IllegalStateException if a new session cannot be
* instantiated for any reason
* @exception IOException if an input/output error occurs while
* processing this request
*/
public Session findSession(String id) throws IOException;
/**
* Return the set of active Sessions associated with this Manager.
* If this Manager has no active Sessions, a zero-length array is returned.
*/
public Session[] findSessions();
/**
* Load any currently active sessions that were previously unloaded
* to the appropriate persistence mechanism, if any. If persistence is not
* supported, this method returns without doing anything.
*
* @exception ClassNotFoundException if a serialized class cannot be
* found during the reload
* @exception IOException if an input/output error occurs
*/
public void load() throws ClassNotFoundException, IOException;
/**
* Remove this Session from the active Sessions for this Manager.
*
* @param session Session to be removed
*/
public void remove(Session session);
/**
* Remove a property change listener from this component.
*
* @param listener The listener to remove
*/
public void removePropertyChangeListener(PropertyChangeListener listener);
/**
* Save any currently active sessions in the appropriate persistence
* mechanism, if any. If persistence is not supported, this method
* returns without doing anything.
*
* @exception IOException if an input/output error occurs
*/
public void unload() throws IOException;
/**
* This method will be invoked by the context/container on a periodic
* basis and allows the manager to implement
* a method that executes periodic tasks, such as expiring sessions etc.
*/
public void backgroundProcess();
/**
* Would the Manager distribute the given session attribute? Manager
* implementations may provide additional configuration options to control
* which attributes are distributable.
*
* @param name The attribute name
* @param value The attribute value
*
* @return {@code true} if the Manager would distribute the given attribute
* otherwise {@code false}
*/
public boolean willAttributeDistribute(String name, Object value);
}