1 /*
2 * Copyright (c) 2012-2024, jcabi.com
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met: 1) Redistributions of source code must retain the above
8 * copyright notice, this list of conditions and the following
9 * disclaimer. 2) Redistributions in binary form must reproduce the above
10 * copyright notice, this list of conditions and the following
11 * disclaimer in the documentation and/or other materials provided
12 * with the distribution. 3) Neither the name of the jcabi.com nor
13 * the names of its contributors may be used to endorse or promote
14 * products derived from this software without specific prior written
15 * permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT
19 * NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
21 * THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
22 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
26 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
28 * OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30 package com.jcabi.aspects;
31
32 import java.lang.annotation.Documented;
33 import java.lang.annotation.ElementType;
34 import java.lang.annotation.Retention;
35 import java.lang.annotation.RetentionPolicy;
36 import java.lang.annotation.Target;
37
38 /**
39 * Annotates an immutable class.
40 *
41 * <p>For example:
42 *
43 * <pre> @Immutable
44 * public class Foo {
45 * private String data;
46 * }</pre>
47 *
48 * <p>As soon as you try to instantiate this class a runtime exception
49 * will be thrown, because this class is mutable.
50 *
51 * @since 0.7.8
52 * @see <a href="http://aspects.jcabi.com">http://aspects.jcabi.com/</a>
53 * @see <a href="http://www.yegor256.com/2014/06/09/objects-should-be-immutable.html">Objects Should Be Immutable, by Yegor Bugayenko</a>
54 */
55 @Documented
56 @Retention(RetentionPolicy.RUNTIME)
57 @Target(ElementType.TYPE)
58 public @interface Immutable {
59 /**
60 * Identifies that an array-type field should be considered immutable. Note
61 * that for an array to be considered immutable, its component type must
62 * also be immutable.
63 * @since 0.17
64 * @todo #33 Let's prevent modifications to arrays having this annotation,
65 * somehow. Perhaps we can create an aspect that will throw an exception
66 * should something try to write into the array. See
67 * https://bugs.eclipse.org/bugs/show_bug.cgi?id=157031
68 */
69 @Documented
70 @Retention(RetentionPolicy.RUNTIME)
71 @Target(ElementType.FIELD)
72 @interface Array {
73 }
74 }