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 * 33 * @author Mike Bostock 34 * @since 10.0 35 */ 36 @Beta 37 @GwtCompatible // but no-op! 38 public final class SerializableTester { SerializableTester()39 private SerializableTester() {} 40 41 /** 42 * Serializes and deserializes the specified object. 43 * 44 * <p><b>GWT warning:</b> Under GWT, this method simply returns its input, as proper GWT 45 * serialization tests require more setup. This no-op behavior allows test authors to intersperse 46 * {@code SerializableTester} calls with other, GWT-compatible tests. 47 * 48 * <p>Note that the specified object may not be known by the compiler to be a {@link 49 * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might 50 * be declared as a {@code List}. 51 * 52 * @return the re-serialized object 53 * @throws RuntimeException if the specified object was not successfully serialized or 54 * deserialized 55 */ 56 @SuppressWarnings("unchecked") reserialize(T object)57 public static <T> T reserialize(T object) { 58 return Platform.reserialize(object); 59 } 60 61 /** 62 * Serializes and deserializes the specified object and verifies that the re-serialized object is 63 * equal to the provided object, that the hashcodes are identical, and that the class of the 64 * re-serialized object is identical to that of the original. 65 * 66 * <p><b>GWT warning:</b> Under GWT, this method simply returns its input, as proper GWT 67 * serialization tests require more setup. This no-op behavior allows test authors to intersperse 68 * {@code SerializableTester} calls with other, GWT-compatible tests. 69 * 70 * <p>Note that the specified object may not be known by the compiler to be a {@link 71 * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might 72 * be declared as a {@code List}. 73 * 74 * <p>Note also that serialization is not in general required to return an object that is 75 * {@linkplain Object#equals equal} to the original, nor is it required to return even an object 76 * of the same class. For example, if sublists of {@code MyList} instances were serializable, 77 * those sublists might implement a private {@code MySubList} type but serialize as a plain {@code 78 * MyList} to save space. So long as {@code MyList} has all the public supertypes of {@code 79 * MySubList}, this is safe. For these cases, for which {@code reserializeAndAssert} is too 80 * strict, use {@link #reserialize}. 81 * 82 * @return the re-serialized object 83 * @throws RuntimeException if the specified object was not successfully serialized or 84 * deserialized 85 * @throws AssertionFailedError if the re-serialized object is not equal to the original object, 86 * or if the hashcodes are different. 87 */ 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