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jsr166 |
1.1 |
/* |
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* Copyright 2002 Sun Microsystems, Inc. All Rights Reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
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* CA 95054 USA or visit www.sun.com if you need additional information or |
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* have any questions. |
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*/ |
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/* |
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* @test |
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* @bug 4684279 |
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* @summary Empty utility collections should be singletons |
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* @author Josh Bloch |
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*/ |
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import java.util.*; |
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import java.io.*; |
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public class EmptyCollectionSerialization { |
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private static Object patheticDeepCopy(Object o) throws Exception { |
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// Serialize |
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ByteArrayOutputStream bos = new ByteArrayOutputStream(); |
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ObjectOutputStream oos = new ObjectOutputStream(bos); |
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oos.writeObject(o); |
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byte[] serializedForm = bos.toByteArray(); |
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// Deserialize |
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InputStream is = new ByteArrayInputStream(serializedForm); |
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ObjectInputStream ois = new ObjectInputStream(is); |
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return ois.readObject(); |
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} |
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private static boolean isSingleton(Object o) throws Exception { |
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return patheticDeepCopy(o) == o; |
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} |
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public static void main(String[] args) throws Exception { |
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if (!isSingleton(Collections.EMPTY_SET)) |
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throw new Exception("EMPTY_SET"); |
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if (!isSingleton(Collections.EMPTY_LIST)) |
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throw new Exception("EMPTY_LIST"); |
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if (!isSingleton(Collections.EMPTY_MAP)) |
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throw new Exception("EMPTY_MAP"); |
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} |
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} |
