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.GwtCompatible; 20 import com.google.errorprone.annotations.CanIgnoreReturnValue; 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 @GwtCompatible // but no-op! 36 @ElementTypesAreNonnullByDefault 37 public final class SerializableTester { 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 @CanIgnoreReturnValue reserialize(T object)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 @CanIgnoreReturnValue reserializeAndAssert(T object)88 public static <T> T reserializeAndAssert(T object) { 89 T copy = reserialize(object); 90 new EqualsTester().addEqualityGroup(object, copy).testEquals(); 91 Assert.assertEquals(object.getClass(), copy.getClass()); 92 return copy; 93 } 94 } 95