[kaffe] java.io.ObjectInputStream: final field cannot be restored
Ito Kazumitsu
ito.kazumitsu at hitachi-cable.co.jp
Tue Mar 23 22:02:02 PST 2004
Hi,
Interested in Prevayler (http://www.prevayler.org/), which is
marked untested in our "Compatibility - Application Testing",
I tried it.
The result was unsatisfactory. The simplest demo of Prevayler
cannot run on kaffe. After studying the cause of the error,
I found something buggy in java.io.ObjectInputStream.
My test program is attaced below. The test shows that a
field that is marked "final" cannot be restored by
java.io.ObjectInputStream#readObject.
I tested it on kaffe 1.1.4, but I have not tested it on the current
CVS version yet.
Results:
The VM on which The VM
ObjectOutputStream ran ObjectInputStream ran Result
---------------------- --------------------- ------
Kaffe 1.1.4 Kaffe 1.1.4 FAIL(1)
Sun's 1.4.2_04 Sun's 1.4.2_04 PASS(2)
Kaffe 1.1.4 Sun's 1.4.2_04 PASS(3)
Sun's 1.4.2_04 Kaffe 1.1.4 FAIL(4)
(1) Kaffe --> Kaffe
$bash java Test01 write | java Test01 read
t2=Test01 at 8291b64 null B
t1=Test01 at 81459b4 A B
(2) Sun --> Sun
bash$ java Test01 write | java Test01 read
t1=Test01 at f9f9d8 A B
t2=Test01 at 1820dda A B
(3) Kaffe --> Sun
bash$ java Test01 write | (Some command that sends data to another machine)
t1=Test01 at 81459b4 A B
bash$ (Some command that received data from another machine) | java Test01 read
t2=Test01 at 1820dda A B
(4) Sun --> Kaffe
bash$ java Test01 write | (Some command that sends data to another machine)
t1=Test01 at f9f9d8 A B
$ (Some command that received data from another machine) | java Test01 read
t2=Test01 at 8291b64 null B
Test program:
import java.io.*;
import java.util.*;
class Test01 implements java.io.Serializable {
private final String s1 = "A";
private String s2 = "B";
public static void main(String args[]) throws Exception {
if (args[0].equals("write")) {
Test01 t1 = new Test01();
ObjectOutputStream stream = new ObjectOutputStream(System.out);
stream.writeObject(t1);
stream.flush();
System.err.println("t1=" + t1 + " " + t1.s1 + " " + t1.s2);
return;
}
if (args[0].equals("read")) {
ObjectInputStream ois = new ObjectInputStream(System.in);
Test01 t2 = (Test01)(ois.readObject());
System.err.println("t2=" + t2 + " " + t2.s1 + " " + t2.s2);
return;
}
}
}
More information about the kaffe
mailing list