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1   /* This file is part of COPAL (COntext Provisioning for All).
2    *
3    * COPAL is a part of SM4All (Smart hoMes for All) project.
4    *
5    * COPAL is free software: you can redistribute it and/or modify
6    * it under the terms of the GNU Lesser General Public License as published by
7    * the Free Software Foundation, either version 3 of the License, or
8    * (at your option) any later version.
9    *
10   * COPAL is distributed in the hope that it will be useful,
11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   * GNU Lesser General Public License for more details.
14   *
15   * You should have received a copy of the GNU Lesser General Public License
16   * along with COPAL. If not, see <http://www.gnu.org/licenses/>.
17   */
18  package at.ac.tuwien.infosys.sm4all.copal.api.event.xml;
19  
20  import org.w3c.dom.Element;
21  import at.ac.tuwien.infosys.sm4all.copal.api.event.ContextEvent;
22  import at.ac.tuwien.infosys.sm4all.copal.api.util.FailedUnmarshallingException;
23  import at.ac.tuwien.infosys.sm4all.copal.api.util.InvalidFieldValueException;
24  
25  /**
26   * The COPAL element for the event's time-to-live,
27   * 
28   * @author sanjin
29   */
30  public class TimeToLive extends ConcreteElement<Long> {
31  
32      @Override
33      protected Long retrieve(final Element element) throws FailedUnmarshallingException {
34          if (element == null)
35              throw new NullPointerException("XML DOM element cannot be null.");
36  
37          final Long result;
38  
39          try {
40              final String textContent = element.getTextContent().trim();
41              if (textContent.isEmpty())
42                  throw new InvalidFieldValueException(
43                          "Time-to-live is empty or blank.");
44              result = Long.parseLong(textContent);
45          } catch (final NumberFormatException ex) {
46              throw new InvalidFieldValueException(
47                      "Time-to-live is not a number.");
48          }
49  
50          return result;
51      }
52  
53      @Override
54      public void update(final Element element, final ContextEvent event) {
55          if (element == null)
56              throw new NullPointerException("XML DOM element cannot be null.");
57          if (event == null)
58              throw new NullPointerException("Context event cannot be null.");
59  
60          element.setTextContent(String.valueOf(event.getTTL()));
61      }
62  
63      /**
64       * Singleton instance.
65       */
66      public static final TimeToLive INSTANCE = new TimeToLive();
67  
68      private TimeToLive() {
69          super(long.class);
70      }
71  }