/*

 * Copyright 1999 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

/* @test

 * @bug 4217737

 * @clean NestedReplace A B C D

 * @build NestedReplace

 * @run main NestedReplace

 * @summary Ensure that replacement objects can nominate their own replacements,

 *          so long as the replacement is not the same class as the

 *          just-replaced object.

 *

 */

import java.io.*;

class A implements Serializable {

    Object writeReplace() throws ObjectStreamException {

        return new B();

    }

}

class B implements Serializable {

    Object writeReplace() throws ObjectStreamException {

        return new C();

    }

}

class C implements Serializable {

    static int writeReplaceCalled = 0;

    Object writeReplace() throws ObjectStreamException {

        writeReplaceCalled++;

        return new C();

    }

    Object readResolve() throws ObjectStreamException {

        return new D();

    }

}

class D implements Serializable {

    Object readResolve() throws ObjectStreamException {

        throw new Error("readResolve() called more than once");

    }

}

public class NestedReplace {

    public static void main(String[] args) throws Exception {

        ByteArrayOutputStream bout;

        ObjectOutputStream oout;

        ByteArrayInputStream bin;

        ObjectInputStream oin;

        Object obj;

        bout = new ByteArrayOutputStream();

        oout = new ObjectOutputStream(bout);

        oout.writeObject(new A());

        oout.flush();

        bin = new ByteArrayInputStream(bout.toByteArray());

        oin = new ObjectInputStream(bin);

        obj = oin.readObject();

        if (! (obj instanceof D))

            throw new Error("Deserialized object is of wrong class");

        if (C.writeReplaceCalled != 1)

            throw new Error("C.writeReplace() should only get called once");

    }

}