001// Copyright 2005 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry; 016 017import java.io.Serializable; 018 019import javax.servlet.http.HttpSessionBindingEvent; 020import javax.servlet.http.HttpSessionBindingListener; 021 022/** 023 * Base implementation of {@link org.apache.tapestry.SessionStoreOptimized}. Subclasses should 024 * invoke {@link #markSessionStoreNeeded()} any time internal state changed. 025 * 026 * @author Howard M. Lewis Ship 027 * @since 4.0 028 */ 029public class BaseSessionStoreOptimized implements SessionStoreOptimized, Serializable, 030 HttpSessionBindingListener 031{ 032 private static final long serialVersionUID = -2786704444616789831L; 033 034 private transient boolean _dirty; 035 036 /** 037 * Clears the dirty flag. 038 */ 039 public void valueBound(HttpSessionBindingEvent event) 040 { 041 _dirty = false; 042 } 043 044 /** 045 * Does nothing. 046 */ 047 public void valueUnbound(HttpSessionBindingEvent event) 048 { 049 } 050 051 /** 052 * Sets the dirty flag. 053 */ 054 protected void markSessionStoreNeeded() 055 { 056 _dirty = true; 057 } 058 059 /** 060 * Returns the dirty flag. 061 */ 062 public boolean isStoreToSessionNeeded() 063 { 064 return _dirty; 065 } 066 067}