1   /* Copyright 2002-2013 CS Systèmes d'Information
2    * Licensed to CS Systèmes d'Information (CS) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * CS licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *   http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.orekit.time;
18  
19  /** This interface represents objects that have a {@link AbsoluteDate}
20   * date attached to them.
21   * <p>Classes implementing this interface can be stored chronologically
22   * in sorted sets using {@link ChronologicalComparator} as the
23   * underlying comparator. An example using for {@link org.orekit.orbits.Orbit
24   * Orbit} instances is given here:</p>
25   * <pre>
26   *     SortedSet&lt;Orbit> sortedOrbits =
27   *         new TreeSet&lt;Orbit>(new ChronologicalComparator());
28   *     sortedOrbits.add(orbit1);
29   *     sortedOrbits.add(orbit2);
30   *     ...
31   * </pre>
32   * <p>This interface is also the base interface used to {@link
33   * org.orekit.utils.TimeStampedCache cache} series of time-dependent
34   * objects for interpolation in a thread-safe manner.</p>
35   * @see AbsoluteDate
36   * @see ChronologicalComparator
37   * @see org.orekit.utils.TimeStampedCache
38   * @author Luc Maisonobe
39   */
40  public interface TimeStamped {
41  
42      /** Get the date.
43       * @return date attached to the object
44       */
45      AbsoluteDate getDate();
46  
47  }