01: /* ====================================================================
02: The Jicarilla Software License
03:
04: Copyright (c) 2003 Leo Simons.
05: All rights reserved.
06:
07: Permission is hereby granted, free of charge, to any person obtaining
08: a copy of this software and associated documentation files (the
09: "Software"), to deal in the Software without restriction, including
10: without limitation the rights to use, copy, modify, merge, publish,
11: distribute, sublicense, and/or sell copies of the Software, and to
12: permit persons to whom the Software is furnished to do so, subject to
13: the following conditions:
14:
15: The above copyright notice and this permission notice shall be
16: included in all copies or substantial portions of the Software.
17:
18: THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19: EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20: MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
21: IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
22: CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
23: TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
24: SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
25: ==================================================================== */
26: package org.jicarilla.lang;
27:
28: /**
29: * <p>An interface implemented by mutable objects whose state can be fully
30: * locked. After an object is made readonly, its state can thereafter not ever
31: * be modified again.</p>
32: *
33: * <p>Ideally, well-behaved objects are always in a consistent state. However,
34: * sometimes this is not feasible, and you will want to call several mutation
35: * methods on objects that are otherwise intended to be immutable. When this
36: * occurs, you have several options, for example, adding a utility class
37: * containing a method like</p>
38: *
39: * <pre>
40: * MyObject MyObjectUtil.unmodifiableMyObject( MyObject object )
41: * </pre>
42: *
43: * <p>That is the approach taken in the Collections API (see {@link
44: * java.util.Collections#unmodifiableList(java.util.List) unmodifiableList()}
45: * and others). The downside there is that you litter your class library with
46: * small utility classes.</p>
47: *
48: * <p>This interface offers an alternative that keeps the immutability support
49: * encapsulated within the actual class.</p>
50: *
51: * @author <a href="lsimons at jicarilla dot org">Leo Simons</a>
52: * @version $Id: ReadonlyEnabled.java,v 1.1 2004/03/23 13:37:56 lsimons Exp $
53: */
54: public interface ReadonlyEnabled {
55: /**
56: * Mark this object as readonly, locking its state in place and not
57: * allowing it to be ever modified again for the duration of the
58: * components' existence.
59: */
60: void makeReadOnly();
61: }
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