ReadResolve.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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/* @test
   @bug 4136620 4144590
   @summary Make sure that Attribute & subclasses are serialized and deserialized correctly
   @modules java.desktop
 */

import java.text.AttributedCharacterIterator.Attribute;
import java.awt.font.TextAttribute;
import java.io.*;

public class ReadResolve {

    public static void main(String[] args) throws Exception {
        testSerializationCycle(Attribute.LANGUAGE);
        testSerializationCycle(TextAttribute.INPUT_METHOD_HIGHLIGHT);

        boolean gotException = false;
        Attribute result = null;
        try {
            result = doSerializationCycle(FakeAttribute.LANGUAGE);
        } catch (Throwable e) {
            gotException = true;
        }
        if (!gotException) {
            throw new RuntimeException("Attribute should throw an exception when given a fake \"language\" attribute. Deserialized object: " + result);
        }
    }

    static Attribute doSerializationCycle(Attribute attribute) throws Exception {

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        ObjectOutputStream  oos  =  new  ObjectOutputStream(baos);
        oos.writeObject(attribute);
        oos.flush();

        byte[] data = baos.toByteArray();

        ByteArrayInputStream bais = new ByteArrayInputStream(data);
        ObjectInputStream ois = new ObjectInputStream(bais);
        Attribute result = (Attribute) ois.readObject();

        return result;
    }

    static void testSerializationCycle(Attribute attribute) throws Exception {
        Attribute result = doSerializationCycle(attribute);
        if (result != attribute) {
            throw new RuntimeException("attribute changed identity during serialization/deserialization");
        }
    }

    private static class FakeAttribute extends Attribute {

        // This LANGUAGE attribute should never be confused with the
        // Attribute.LANGUAGE attribute. However, we don't override
        // readResolve here, so that deserialization goes
        // to Attribute. Attribute has to catch this problem and reject
        // the fake attribute.
        static final FakeAttribute LANGUAGE = new FakeAttribute("language");

        FakeAttribute(String name) {
            super(name);
        }
    }
}