test/java/io/Externalizable/compatibility/ExternalizableBlockData.java

/*
 * Copyright (c) 2000, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/* @test
 * @bug 4089540
 * @summary Verify compatibility with 1.1 externalizable format
 */

import java.io.*;
import java.util.*;

class Foo implements Externalizable {
    private static final long serialVersionUID = 0xbabel;

    int x;
    int y;
    Object obj;

    public Foo() {
    }

    public Foo(int x, int y, Object obj) {
        this.x = x;
        this.y = y;
        this.obj = obj;
    }

    public void writeExternal(ObjectOutput out) throws IOException {
        out.writeInt(x);
        out.writeInt(y);
        out.writeObject(obj);
    }

    public void readExternal(ObjectInput in)
        throws IOException, ClassNotFoundException
    {
        x = in.readInt();
        y = in.readInt();
        obj = in.readObject();
    }

    public boolean equals(Object other) {
        if (other instanceof Foo) {
            Foo f = (Foo) other;
            return ((x == f.x) && (y == f.y) &&
                    ((obj != null) ? obj.equals(f.obj) : (f.obj == null)));
        }
        return false;
    }
}

public class ExternalizableBlockData {
    public static void main(String[] args) throws Exception {
        byte[] oldExternalizableBytes = getFileBytes(
                new File(System.getProperty("test.src", "."), "old.ser"));
        Foo foo = new Foo(0xbad, 0xbeef, "burrito");
        ByteArrayOutputStream bout = new ByteArrayOutputStream();
        ObjectOutputStream oout = new ObjectOutputStream(bout);
        oout.useProtocolVersion(ObjectStreamConstants.PROTOCOL_VERSION_1);
        oout.writeObject(foo);
        oout.close();
        if (! Arrays.equals(bout.toByteArray(), oldExternalizableBytes)) {
            throw new Error();
        }

        ObjectInputStream oin = new ObjectInputStream(
                new ByteArrayInputStream(oldExternalizableBytes));
        if (! foo.equals(oin.readObject())) {
            throw new Error();
        }

        bout = new ByteArrayOutputStream();
        oout = new ObjectOutputStream(bout);
        oout.writeObject(foo);
        oout.close();
        if (Arrays.equals(bout.toByteArray(), oldExternalizableBytes)) {
            throw new Error();
        }
    }

    static byte[] getFileBytes(File file) throws IOException {
        FileInputStream fin = new FileInputStream(file);
        ByteArrayOutputStream bout = new ByteArrayOutputStream();
        byte[] buf = new byte[256];
        int n;

        while ((n = fin.read(buf)) != -1) {
            bout.write(buf, 0, n);
        }
        fin.close();
        return bout.toByteArray();
    }
}