[Jython-bugs] [Bug #127340] Problem with serializable method parameters

[<no...@so...>]

Bug #127340, was updated on 2001-Jan-02 14:42
Here is a current snapshot of the bug.

Project: Jython
Category: Core
Status: Open
Resolution: Later
Bug Group: None
Priority: 5
Submitted by: njcarriero
Assigned to : nobody
Summary: Problem with serializable method parameters

Details: An object crossing from jython to java seems to lose its identity
if passed as a serializable object . The following illustrates the
problem.

==== Output from java ====
[carriero@callisto kinase-search]$ java TellMeMore
class java.util.Hashtable
{zwei=two, uno=one}
class java.util.Hashtable
{zwei=two, uno=one}

==== Output from jython 2.0b1 ====
[carriero@callisto kinase-search]$
/home/carriero/jython/jython-2.0b1/jython tmm.py
class java.util.Hashtable
{zwei=two, uno=one}
class org.python.core.PyJavaInstance
org.python.core.PyJavaInstance@38ed7d

==== Python source ====

from java.util import *
import TellMeMore

h = Hashtable()

h.put("uno", "one")
h.put("zwei", "two")

tmm = TellMeMore()

tmm.TellMeMoreO(h)
tmm.dump()

tmm.TellMeMoreS(h)
tmm.dump()

==== Java source ====

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

public class TellMeMore  {
    Object	o;

    public void TellMeMoreS(Serializable o) {
	this.o = o;
    }

    public void TellMeMoreO(Object o) {
	this.o = o;
    }
    
    public void dump() {
	System.out.println(o.getClass());
	System.out.println(o.toString());
    }
    
    public static void main(String args[]) {
	Hashtable h = new Hashtable();
	h.put("uno", "one");
	h.put("zwei", "two");

	TellMeMore tmm = new TellMeMore();

	tmm.TellMeMoreO(h);
	tmm.dump();
	tmm.TellMeMoreS(h);
	tmm.dump();

    }
}


Follow-Ups:

Date: 2001-Jan-03 03:20
By: bckfnn

Comment:
This problem have been raised before and we quick forgot all about it:

http://mail.python.org/pipermail/jpython-interest/1999-July/001944.html

I don't feel that the solution Jim describe is such a big hack, but it does
require changes to the highly sensitive __tojava__() methods in the
classes:

PyClass
PyFloat
PyInstance
PyInteger
PyLong
PyString

Because such a change will need a long period if test, I'll delay the fix
until after the 2.0 release.
-------------------------------------------------------

For detailed info, follow this link:
http://sourceforge.net/bugs/?func=detailbug&bug_id=127340&group_id=12867