org.apache.catalina.Manager Maven / Gradle / Ivy
/*
* 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 Manager manages the pool of Sessions that are associated with a
* particular Context. 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.
*
* In order for a Manager implementation to successfully operate
* with a Context implementation that implements reloading, it
* must obey the following constraints:
*
* - Must implement
Lifecycle so that the Context can indicate
* that a restart is required.
* - Must allow a call to
stop() to be followed by a call to
* start() on the same Manager instance.
*
*
* @author Craig R. McClanahan
*/
public interface Manager {
// ------------------------------------------------------------- Properties
/**
* Get the Context with which this Manager is associated.
*
* @return The associated Context
*/
public Context getContext();
/**
* Set the Context with which this Manager is associated. The Context 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 Context (including
* setting a {@code null} value) that the Manager is associated with.
*
* @param context The newly associated Context
*/
public void setContext(Context context);
/**
* @return the session id generator
*/
public SessionIdGenerator getSessionIdGenerator();
/**
* Sets the session id generator
*
* @param sessionIdGenerator The session id generator
*/
public void setSessionIdGenerator(SessionIdGenerator sessionIdGenerator);
/**
* Returns the total number of sessions created by this manager.
*
* @return Total number of sessions created by this manager.
*/
public long getSessionCounter();
/**
* Sets the total number of sessions created by this manager.
*
* @param sessionCounter Total number of sessions created by this manager.
*/
public void setSessionCounter(long 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 long getExpiredSessions();
/**
* Sets the number of sessions that have expired.
*
* @param expiredSessions Number of sessions that have expired
*/
public void setExpiredSessions(long 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();
/**
* 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. This may be based on sample data.
*
* @return Average time (in seconds) that expired sessions had been
* alive.
*/
public int getSessionAverageAliveTime();
/**
* Gets the current rate of session creation (in session per minute). This
* may be based on sample data.
*
* @return The current rate (in sessions per minute) of session creation
*/
public int getSessionCreateRate();
/**
* Gets the current rate of session expiration (in session per minute). This
* may be based on sample data
*
* @return The current rate (in sessions per minute) of session expiration
*/
public int getSessionExpireRate();
// --------------------------------------------------------- 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);
/**
* Change the session ID of the current session to a specified session ID.
*
* @param session The session to change the session ID for
* @param newId new session ID
*/
public void changeSessionId(Session session, String newId);
/**
* 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.
*
* @return An empty Session object
*/
public Session createEmptySession();
/**
* 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
* null.
*
* @param sessionId The session id which should be used to create the
* new session; if null, 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
*
* @return An empty Session object with the given ID or a newly created
* session ID if none was specified
*/
public Session createSession(String sessionId);
/**
* Return the active Session, associated with this Manager, with the
* specified session id (if any); otherwise return null.
*
* @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
*
* @return the request session or {@code null} if a session with the
* requested ID could not be found
*/
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.
*
* @return All the currently active sessions managed by this manager
*/
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 this Session from the active Sessions for this Manager.
*
* @param session Session to be removed
* @param update Should the expiration statistics be updated
*/
public void remove(Session session, boolean update);
/**
* 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);
}