Serialization: parent readResolve tests

[Daniel Bonniot <Daniel dot Bonniot at inria dot fr>]

Hi,

These are tests for deserialization, in the case where the object's class's 
parent has a readResolve class. I put the rationale for the tests in comments 
in the source. All tested free runtimes (kaffe, gij, gcj, jamvm) get this 
wrong when that readResolve is visible. (sablevm fails with todo errors)

By the way, I'm a developer for the Nice project, an advanced open source 
extension of Java. By trying to bootstrap or running our testsuite on free 
VMs, I occasionally run into bugs that call for a mauve test. Would it make 
sense for me to ask for cvs write access?

Cheers,

Daniel
--
The Nice programming language: http://nice.sf.net

// Tags: JDK1.1

// Copyright (C) 2005 Daniel Bonniot <bonniot@users.sf.net>

// This file is part of Mauve.

// Mauve is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2, or (at your option)
// any later version.

// Mauve 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 for more details.

// You should have received a copy of the GNU General Public License
// along with Mauve; see the file COPYING.  If not, write to
// the Free Software Foundation, 59 Temple Place - Suite 330,
// Boston, MA 02111-1307, USA.  */

package gnu.testlet.java.io.Serializable;

import gnu.testlet.TestHarness;
import gnu.testlet.Testlet;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

/**
 * Check when a parent readResolve() method should be used for subclasses.
 *
 * Here is the rationale for this test, based on Sun's javadoc for
 * java.io.Serializable:
 *
 * First, readResolve must be declared with:
 *   ANY-ACCESS-MODIFIER Object readResolve() throws ObjectStreamException;
 * Thus, a non-private readResolve is OK.
 *
 * Second, the rules for invoking readResolve (as for writeReplace) are that
 * it must be called if it would be accessible from the class of the object
 * being deserialized. So, a non-private readSolve method in the parent must
 * be called, but a private one should not be.
 */
public class ParentReadResolve implements Testlet {

  public void test(TestHarness harness)
  {
    try {
      ByteArrayOutputStream outb = new ByteArrayOutputStream();
      ObjectOutputStream outs = new ObjectOutputStream(outb);

      outs.writeObject(MySingleton.instance);
      outs.writeObject(new MyFoo());

      byte[] store = outb.toByteArray();

      ByteArrayInputStream inb = new ByteArrayInputStream(store);
      ObjectInputStream ins = new ObjectInputStream(inb);

      MySingleton x = (MySingleton) ins.readObject();
      harness.check(x == MySingleton.instance);

      MyFoo foo = (MyFoo) ins.readObject();
      harness.check(! foo.resolved);
    }
    catch (Throwable e) {
      harness.debug(e);
    }
  }

  //// Singleton/MySingleton with a non-private readResolve ////

  static abstract class Singleton implements java.io.Serializable
  {
    abstract Singleton getInstance();

    /** NOTE: this readResolve is not private.
     */
    Object readResolve() {
      return getInstance();
    }
  }

  static class MySingleton extends Singleton
  {
    static final MySingleton instance = new MySingleton();

    Singleton getInstance() { return instance; }
  }

  //// Foo/MyFoo with a private readResolve ////

  static abstract class Foo implements java.io.Serializable
  {
    boolean resolved = false;

    /** NOTE: this readResolve is private.
     */
    private Object readResolve() {
      resolved = true;
      return this;
    }
  }

  static class MyFoo extends Foo
  {
  }
}

? gnu/testlet/java/io/Serializable/ParentReadResolve.java
Index: ChangeLog
===================================================================
RCS file: /cvs/mauve/mauve/ChangeLog,v
retrieving revision 1.893
diff -u -r1.893 ChangeLog
--- ChangeLog	24 Feb 2005 20:53:29 -0000	1.893
+++ ChangeLog	26 Feb 2005 00:31:11 -0000
@@ -1,3 +1,7 @@
+2005-02-26  Daniel Bonniot  <bonniot@users.sourceforge.net>
+
+	* gnu/testlet/java/io/Serializable/ParentReadResolve.java: New test.
+
 2005-02-24  Audrius Meskauskas  <audriusa@bluewin.ch>
 
     * gnu/testlet/javax/swing/JFrame/paint5.java: New test.