Name: nt126004 Date: 02/24/2003


FULL PRODUCT VERSION :
java version "1.4.1_01"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1_01-b01)
Java HotSpot(TM) Client VM (build 1.4.1_01-b01, mixed mode)

FULL OPERATING SYSTEM VERSION :
Microsoft Windows XP [Version 5.1.2600]

A DESCRIPTION OF THE PROBLEM :
I created a BigInteger with a String as parameter. Calling
"longValue()" returns the correct value.

Then, I serialized and deserialized the BigInteger
(DataOutputStream + FileOutputStream). After
deserialization, the method "longValue()" returns an
incorrect value.

  Interestingly, the method "toString()" of the deserialized
BigInteger still returns the correct value. Just
"longValue()" causes a problem.

This bug does not occur with all values, but I found two
values where the problem occurs (see attached source code).

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Just compile the attached source code and you will see the
problem.

EXPECTED VERSUS ACTUAL BEHAVIOR :
This is the output of the attached program. You can see,
that longValue() returns a different value after
deserialization:


created BigInteger (before serialization):
toString=-2882303761517117440, longValue=-2882303761517117440

serialized and deserialized object

BigInteger after deserialization:
toString=-2882303761517117440, longValue=-2882303765812084736

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.math.BigInteger;

public class BigIntegerTest {
    
    public static void main(String[] args) {
        //BigInteger bigInteger = new BigInteger("-7493989779944505344");
        BigInteger bigInteger = new BigInteger("-2882303761517117440");
        System.out.println("created BigInteger (before serialization):");
        System.out.println("toString=" + bigInteger + ", longValue=" +
bigInteger.longValue());
        System.out.println();
        
        try {
            FileOutputStream fileOut = new FileOutputStream(new
File("biginteger.ser"));
            ObjectOutputStream objectOut = new ObjectOutputStream(fileOut);
            objectOut.writeObject(bigInteger);
            objectOut.close();
            
            FileInputStream fileIn = new FileInputStream(new
File("biginteger.ser"));
            ObjectInputStream objectIn = new ObjectInputStream(fileIn);
            bigInteger = (BigInteger) objectIn.readObject();
            objectIn.close();
            System.out.println("serialized and deserialized object");
            System.out.println();
            
            System.out.println("BigInteger after deserialization: ");
            System.out.println("toString=" + bigInteger + ", longValue=" +
bigInteger.longValue());
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }
}

---------- END SOURCE ----------

CUSTOMER WORKAROUND :
Do not use BigInteger.longValue() or BigDecimal.longValue()
(Review ID: 181559)
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