/*
* 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>Store</b> is the abstraction of a Catalina component that provides persistent storage and loading of Sessions
* and their associated user data. Implementations are free to save and load the Sessions to any media they wish, but it
* is assumed that saved Sessions are persistent across server or context restarts.
*/
public interface Store {
/**
* @return the Manager instance associated with this Store.
*/
Manager getManager();
/**
* Set the Manager associated with this Store.
*
* @param manager The Manager which will use this Store.
*/
void setManager(Manager manager);
/**
* @return the number of Sessions present in this Store.
*
* @exception IOException if an input/output error occurs
*/
int getSize() throws IOException;
/**
* Add a property change listener to this component.
*
* @param listener The listener to add
*/
void addPropertyChangeListener(PropertyChangeListener listener);
/**
* @return an array containing the session identifiers of all Sessions currently saved in this Store. If there are
* no such Sessions, a zero-length array is returned.
*
* @exception IOException if an input/output error occurred
*/
String[] keys() throws IOException;
/**
* Load and return the Session associated with the specified session identifier from this Store, without removing
* it. If there is no such stored Session, return <code>null</code>.
* <p>
* Implementations should expect, and correctly handle, concurrent calls to any method but in particular calls to
* {@code #load(String)}, {@code #save(Session)} and {@code #remove(String)} for the same session.
* <p>
* The session ID is user provided so stores must treat it as untrusted data.
*
* @param id Session identifier of the session to load
*
* @exception ClassNotFoundException if a deserialization error occurs
* @exception IOException if an input/output error occurs
*
* @return the loaded Session instance
*/
Session load(String id) throws ClassNotFoundException, IOException;
/**
* Remove the Session with the specified session identifier from this Store, if present. If no such Session is
* present, this method takes no action.
* <p>
* Implementations should expect, and correctly handle, concurrent calls to any method but in particular calls to
* {@code #load(String)}, {@code #save(Session)} and {@code #remove(String)} for the same session.
* <p>
* The session ID is user provided so stores must treat it as untrusted data.
*
* @param id Session identifier of the Session to be removed
*
* @exception IOException if an input/output error occurs
*/
void remove(String id) throws IOException;
/**
* Remove all Sessions from this Store.
*
* @exception IOException if an input/output error occurs
*/
void clear() throws IOException;
/**
* Remove a property change listener from this component.
*
* @param listener The listener to remove
*/
void removePropertyChangeListener(PropertyChangeListener listener);
/**
* Save the specified Session into this Store. Any previously saved information for the associated session
* identifier is replaced.
* <p>
* Implementations should expect, and correctly handle, concurrent calls to any method but in particular calls to
* {@code #load(String)}, {@code #save(Session)} and {@code #remove(String)} for the same session.
*
* @param session Session to be saved
*
* @exception IOException if an input/output error occurs
*/
void save(Session session) throws IOException;
}