001/* 002 * Copyright (C) 2007 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package com.google.common.testing; 018 019import com.google.common.annotations.Beta; 020import com.google.common.annotations.GwtCompatible; 021import junit.framework.Assert; 022import junit.framework.AssertionFailedError; 023 024/** 025 * Tests serialization and deserialization of an object, optionally asserting that the resulting 026 * object is equal to the original. 027 * 028 * <p><b>GWT warning:</b> Under GWT, both methods simply returns their input, as proper GWT 029 * serialization tests require more setup. This no-op behavior allows test authors to intersperse 030 * {@code SerializableTester} calls with other, GWT-compatible tests. 031 * 032 * 033 * @author Mike Bostock 034 * @since 10.0 035 */ 036@Beta 037@GwtCompatible // but no-op! 038public final class SerializableTester { 039 private SerializableTester() {} 040 041 /** 042 * Serializes and deserializes the specified object. 043 * 044 * <p><b>GWT warning:</b> Under GWT, this method simply returns its input, as proper GWT 045 * serialization tests require more setup. This no-op behavior allows test authors to intersperse 046 * {@code SerializableTester} calls with other, GWT-compatible tests. 047 * 048 * <p>Note that the specified object may not be known by the compiler to be a {@link 049 * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might 050 * be declared as a {@code List}. 051 * 052 * @return the re-serialized object 053 * @throws RuntimeException if the specified object was not successfully serialized or 054 * deserialized 055 */ 056 @SuppressWarnings("unchecked") 057 public static <T> T reserialize(T object) { 058 return Platform.reserialize(object); 059 } 060 061 /** 062 * Serializes and deserializes the specified object and verifies that the re-serialized object is 063 * equal to the provided object, that the hashcodes are identical, and that the class of the 064 * re-serialized object is identical to that of the original. 065 * 066 * <p><b>GWT warning:</b> Under GWT, this method simply returns its input, as proper GWT 067 * serialization tests require more setup. This no-op behavior allows test authors to intersperse 068 * {@code SerializableTester} calls with other, GWT-compatible tests. 069 * 070 * <p>Note that the specified object may not be known by the compiler to be a {@link 071 * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might 072 * be declared as a {@code List}. 073 * 074 * <p>Note also that serialization is not in general required to return an object that is 075 * {@linkplain Object#equals equal} to the original, nor is it required to return even an object 076 * of the same class. For example, if sublists of {@code MyList} instances were serializable, 077 * those sublists might implement a private {@code MySubList} type but serialize as a plain {@code 078 * MyList} to save space. So long as {@code MyList} has all the public supertypes of {@code 079 * MySubList}, this is safe. For these cases, for which {@code reserializeAndAssert} is too 080 * strict, use {@link #reserialize}. 081 * 082 * @return the re-serialized object 083 * @throws RuntimeException if the specified object was not successfully serialized or 084 * deserialized 085 * @throws AssertionFailedError if the re-serialized object is not equal to the original object, 086 * or if the hashcodes are different. 087 */ 088 public static <T> T reserializeAndAssert(T object) { 089 T copy = reserialize(object); 090 new EqualsTester().addEqualityGroup(object, copy).testEquals(); 091 Assert.assertEquals(object.getClass(), copy.getClass()); 092 return copy; 093 } 094}