/*
    * 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.myfaces.context.servlet;
  
  import java.util.Enumeration;
  import java.util.Map;
  
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpSession;
  
  import org.apache.myfaces.shared_impl.util.NullEnumeration;
  import org.apache.myfaces.util.AbstractThreadSafeAttributeMap;
  
  
  /**
   * HttpSession attibutes as Map.
   *
   * @author Anton Koinov (latest modification by $Author: lu4242 $)
   * @version $Revision: 1000660 $ $Date: 2010-09-23 18:02:43 -0500 (Thu, 23 Sep 2010) $
   */
  public class SessionMap extends AbstractThreadSafeAttributeMap
  {
      private final HttpServletRequest _httpRequest;
  
      SessionMap(HttpServletRequest httpRequest)
      {
          _httpRequest = httpRequest;
      }
  
      protected Object getAttribute(String key)
      {
          HttpSession httpSession = getSession();
          return (httpSession == null)
              ? null : httpSession.getAttribute(key.toString());
      }
  
      protected void setAttribute(String key, Object value)
      {
          _httpRequest.getSession(true).setAttribute(key, value);
      }
  
      protected void removeAttribute(String key)
      {
          HttpSession httpSession = getSession();
          if (httpSession != null)
          {
              httpSession.removeAttribute(key);
          }
      }
  
      protected Enumeration getAttributeNames()
      {
          HttpSession httpSession = getSession();
          return (httpSession == null)
              ? NullEnumeration.instance()
              : httpSession.getAttributeNames();
      }
  
      private HttpSession getSession()
      {
          return _httpRequest.getSession(false);
      }
  
  
      public void putAll(Map t)
      {
          throw new UnsupportedOperationException();
      }
  
  
      public void clear()
      {
          throw new UnsupportedOperationException();
      }
  }