Java

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/*
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 * Copyright (C) 2007 The Guava Authors
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 *
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 * Licensed under the Apache License, Version 2.0 (the "License");
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 * you may not use this file except in compliance with the License.
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 * You may obtain a copy of the License at
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 *
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 * http://www.apache.org/licenses/LICENSE-2.0
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 *
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 * Unless required by applicable law or agreed to in writing, software
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * See the License for the specific language governing permissions and
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 * limitations under the License.
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 */
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package com.google.common.testing;
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import com.google.common.annotations.GwtCompatible;
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import com.google.errorprone.annotations.CanIgnoreReturnValue;
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import junit.framework.Assert;
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import junit.framework.AssertionFailedError;
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/**
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 * Tests serialization and deserialization of an object, optionally asserting that the resulting
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 * object is equal to the original.
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 *
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 * <p><b>GWT warning:</b> Under GWT, both methods simply returns their input, as proper GWT
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 * serialization tests require more setup. This no-op behavior allows test authors to intersperse
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 * {@code SerializableTester} calls with other, GWT-compatible tests.
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 *
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 * @author Mike Bostock
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 * @since 10.0
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 */
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@GwtCompatible // but no-op!
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@ElementTypesAreNonnullByDefault
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public final class SerializableTester {
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  private SerializableTester() {}
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  /**
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   * Serializes and deserializes the specified object.
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   *
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   * <p><b>GWT warning:</b> Under GWT, this method simply returns its input, as proper GWT
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   * serialization tests require more setup. This no-op behavior allows test authors to intersperse
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   * {@code SerializableTester} calls with other, GWT-compatible tests.
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   *
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   * <p>Note that the specified object may not be known by the compiler to be a {@link
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   * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might
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   * be declared as a {@code List}.
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   *
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   * @return the re-serialized object
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   * @throws RuntimeException if the specified object was not successfully serialized or
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   *     deserialized
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   */
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  @CanIgnoreReturnValue
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  public static <T> T reserialize(T object) {
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    return Platform.reserialize(object);
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  }
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  /**
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   * Serializes and deserializes the specified object and verifies that the re-serialized object is
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   * equal to the provided object, that the hashcodes are identical, and that the class of the
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   * re-serialized object is identical to that of the original.
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   *
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   * <p><b>GWT warning:</b> Under GWT, this method simply returns its input, as proper GWT
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   * serialization tests require more setup. This no-op behavior allows test authors to intersperse
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   * {@code SerializableTester} calls with other, GWT-compatible tests.
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   *
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   * <p>Note that the specified object may not be known by the compiler to be a {@link
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   * java.io.Serializable} instance, and is thus declared an {@code Object}. For example, it might
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   * be declared as a {@code List}.
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   *
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   * <p>Note also that serialization is not in general required to return an object that is
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   * {@linkplain Object#equals equal} to the original, nor is it required to return even an object
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   * of the same class. For example, if sublists of {@code MyList} instances were serializable,
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   * those sublists might implement a private {@code MySubList} type but serialize as a plain {@code
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   * MyList} to save space. So long as {@code MyList} has all the public supertypes of {@code
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   * MySubList}, this is safe. For these cases, for which {@code reserializeAndAssert} is too
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   * strict, use {@link #reserialize}.
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   *
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   * @return the re-serialized object
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   * @throws RuntimeException if the specified object was not successfully serialized or
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   *     deserialized
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   * @throws AssertionFailedError if the re-serialized object is not equal to the original object,
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   *     or if the hashcodes are different.
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   */
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  @CanIgnoreReturnValue
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  public static <T> T reserializeAndAssert(T object) {
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    T copy = reserialize(object);
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    new EqualsTester().addEqualityGroup(object, copy).testEquals();
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    Assert.assertEquals(object.getClass(), copy.getClass());
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    return copy;
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  }
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}
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