Java tutorial
/* * $Id: PortletSessionMap.java 471756 2006-11-06 15:01:43Z husted $ * * 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.struts2.portlet; import java.util.AbstractMap; import java.util.Enumeration; import java.util.HashSet; import java.util.Map; import java.util.Set; import javax.portlet.PortletRequest; import javax.portlet.PortletSession; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * A simple implementation of the {@link java.util.Map} interface to handle a collection of portlet session * attributes. The {@link #entrySet()} method enumerates over all session attributes and creates a Set of entries. * Note, this will occur lazily - only when the entry set is asked for. * */ public class PortletSessionMap extends AbstractMap { private static final Log LOG = LogFactory.getLog(PortletSessionMap.class); private PortletSession session = null; private Set<Object> entries = null; /** * Creates a new session map given a portlet request. * * @param request the portlet request object. */ public PortletSessionMap(PortletRequest request) { this.session = request.getPortletSession(); if (LOG.isDebugEnabled()) { LOG.debug("Dumping session info: "); Enumeration enumeration = session.getAttributeNames(); while (enumeration.hasMoreElements()) { String key = (String) enumeration.nextElement(); Object val = session.getAttribute(key); LOG.debug(key + " = " + val); } } } /** * @see java.util.Map#entrySet() */ public Set entrySet() { synchronized (session) { if (entries == null) { entries = new HashSet<Object>(); Enumeration enumeration = session.getAttributeNames(); while (enumeration.hasMoreElements()) { final String key = enumeration.nextElement().toString(); final Object value = session.getAttribute(key); entries.add(new Map.Entry() { public boolean equals(Object obj) { Map.Entry entry = (Map.Entry) obj; return ((key == null) ? (entry.getKey() == null) : key.equals(entry.getKey())) && ((value == null) ? (entry.getValue() == null) : value.equals(entry.getValue())); } public int hashCode() { return ((key == null) ? 0 : key.hashCode()) ^ ((value == null) ? 0 : value.hashCode()); } public Object getKey() { return key; } public Object getValue() { return value; } public Object setValue(Object obj) { session.setAttribute(key, obj); return value; } }); } } } return entries; } /** * Returns the session attribute associated with the given key or * <tt>null</tt> if it doesn't exist. * * @param key the name of the session attribute. * @return the session attribute or <tt>null</tt> if it doesn't exist. */ public Object get(Object key) { synchronized (session) { return session.getAttribute(key.toString()); } } /** * Saves an attribute in the session. * * @param key the name of the session attribute. * @param value the value to set. * @return the object that was just set. */ public Object put(Object key, Object value) { synchronized (session) { entries = null; session.setAttribute(key.toString(), value); return get(key); } } /** * @see java.util.Map#clear() */ public void clear() { synchronized (session) { entries = null; session.invalidate(); } } /** * Removes the specified session attribute. * * @param key the name of the attribute to remove. * @return the value that was removed or <tt>null</tt> if the value was * not found (and hence, not removed). */ public Object remove(Object key) { synchronized (session) { entries = null; Object value = get(key); session.removeAttribute(key.toString()); return value; } } }