1   /**
2    * Copyright (c) 2000-2009 Liferay, Inc. All rights reserved.
3    *
4    * Permission is hereby granted, free of charge, to any person obtaining a copy
5    * of this software and associated documentation files (the "Software"), to deal
6    * in the Software without restriction, including without limitation the rights
7    * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8    * copies of the Software, and to permit persons to whom the Software is
9    * furnished to do so, subject to the following conditions:
10   *
11   * The above copyright notice and this permission notice shall be included in
12   * all copies or substantial portions of the Software.
13   *
14   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20   * SOFTWARE.
21   */
22  
23  package com.liferay.portal.servlet;
24  
25  import java.io.Serializable;
26  
27  import java.util.Map;
28  import java.util.concurrent.ConcurrentHashMap;
29  
30  import javax.servlet.http.HttpSession;
31  
32  /**
33   * <a href="SharedSessionAttributeCache.java.html"><b><i>View Source</i></b></a>
34   *
35   * @author Michael C. Han
36   *
37   */
38  public class SharedSessionAttributeCache implements Serializable {
39  
40      public static SharedSessionAttributeCache getInstance(HttpSession session) {
41          synchronized (session) {
42              SharedSessionAttributeCache cache =
43                  (SharedSessionAttributeCache)session.getAttribute(_SESSION_KEY);
44  
45              if (cache == null) {
46                  cache = new SharedSessionAttributeCache();
47  
48                  session.setAttribute(_SESSION_KEY, cache);
49              }
50  
51              return cache;
52          }
53      }
54  
55      public boolean contains(String name) {
56          return _attributes.containsKey(name);
57      }
58  
59      public Map<String, Object> getValues() {
60          return _attributes;
61      }
62  
63      public void removeAttribute(String key) {
64          _attributes.remove(key);
65      }
66  
67      public void setAttribute(String key, Object value) {
68          _attributes.put(key, value);
69      }
70  
71      private SharedSessionAttributeCache() {
72          _attributes = new ConcurrentHashMap<String, Object>();
73      }
74  
75      private static final String _SESSION_KEY =
76          SharedSessionAttributeCache.class.getName();
77  
78      private Map<String, Object> _attributes;
79  
80  }