1   /**
2    * Copyright (c) 2000-2007 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.kernel.util;
24  
25  import java.util.Properties;
26  
27  /**
28   * <a href="NullSafeProperties.java.html"><b><i>View Source</i></b></a>
29   *
30   * @author Brian Wing Shun Chan
31   *
32   */
33  public class NullSafeProperties extends Properties {
34  
35      public NullSafeProperties() {
36          super();
37      }
38  
39      public Object put(Object key, Object value) {
40          if (key == null) {
41              return null;
42          }
43          else {
44              if (value == null) {
45                  return super.remove(key);
46              }
47              else {
48                  return super.put(key, value);
49              }
50          }
51      }
52  
53      public Object remove(Object key) {
54          if (key == null) {
55              return null;
56          }
57          else {
58              return super.remove(key);
59          }
60      }
61  
62  }