1 /*
2 * Copyright (C) 2007 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package com.google.common.testing;
18
19 import com.google.common.annotations.Beta;
20 import com.google.common.annotations.GwtCompatible;
21 import junit.framework.Assert;
22 import junit.framework.AssertionFailedError;
23
24 /**
25 * Tests serialization and deserialization of an object, optionally asserting that the resulting
26 * object is equal to the original.
27 *
28 * <p><b>GWT warning:</b> Under GWT, both methods simply returns their input, as proper GWT
29 * serialization tests require more setup. This no-op behavior allows test authors to intersperse
30 * {@code SerializableTester} calls with other, GWT-compatible tests.
31 *
32 * @author Mike Bostock
33 * @since 10.0
34 */
35 @Beta
36 @GwtCompatible // but no-op!
37 public final class SerializableTester {
38 private SerializableTester() {}
39
40 /**
41 * Serializes and deserializes the specified object.
42 *
43 * <p><b>GWT warning:</b> Under GWT, this method simply returns its input, as proper GWT
44 * serialization tests require more setup. This no-op behavior allows test authors to intersperse
45 * {@code SerializableTester} calls with other, GWT-compatible tests.
46 *
47 * <p>Note that the specified object may not be known by the compiler to be a {@link
48 * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might
49 * be declared as a {@code List}.
50 *
51 * @return the re-serialized object
52 * @throws RuntimeException if the specified object was not successfully serialized or
53 * deserialized
54 */
55 @SuppressWarnings("unchecked")
56 public static <T> T reserialize(T object) {
57 return Platform.reserialize(object);
58 }
59
60 /**
61 * Serializes and deserializes the specified object and verifies that the re-serialized object is
62 * equal to the provided object, that the hashcodes are identical, and that the class of the
63 * re-serialized object is identical to that of the original.
64 *
65 * <p><b>GWT warning:</b> Under GWT, this method simply returns its input, as proper GWT
66 * serialization tests require more setup. This no-op behavior allows test authors to intersperse
67 * {@code SerializableTester} calls with other, GWT-compatible tests.
68 *
69 * <p>Note that the specified object may not be known by the compiler to be a {@link
70 * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might
71 * be declared as a {@code List}.
72 *
73 * <p>Note also that serialization is not in general required to return an object that is
74 * {@linkplain Object#equals equal} to the original, nor is it required to return even an object
75 * of the same class. For example, if sublists of {@code MyList} instances were serializable,
76 * those sublists might implement a private {@code MySubList} type but serialize as a plain {@code
77 * MyList} to save space. So long as {@code MyList} has all the public supertypes of {@code
78 * MySubList}, this is safe. For these cases, for which {@code reserializeAndAssert} is too
79 * strict, use {@link #reserialize}.
80 *
81 * @return the re-serialized object
82 * @throws RuntimeException if the specified object was not successfully serialized or
83 * deserialized
84 * @throws AssertionFailedError if the re-serialized object is not equal to the original object,
85 * or if the hashcodes are different.
86 */
87 public static <T> T reserializeAndAssert(T object) {
88 T copy = reserialize(object);
89 new EqualsTester().addEqualityGroup(object, copy).testEquals();
90 Assert.assertEquals(object.getClass(), copy.getClass());
91 return copy;
92 }
93 }