Name: nt126004 Date: 07/17/2002


FULL PRODUCT VERSION :
java version "1.4.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-b92)
Java HotSpot(TM) Client VM (build 1.4.0-b92, mixed mode)

FULL OPERATING SYSTEM VERSION :
Microsoft Windows 2000 [Version 5.00.2195]

A DESCRIPTION OF THE PROBLEM :
When writing out many primitive types in a row to an
ObjectOutputStream, then the reverse will fail, i.e.
reading the primitive types in the exact same order from an
ObjectInputStream will generate an error. This is due to
incorrect handling of the block data mode feature.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
The program below always produces the error. The program
will fail with a java.io.EOFException after having read the
768th element from the ObjectInputStream.

---------------------------------

import java.io.*;

public class Javabug
{
public static void main(String args[]) {
try {
System.out.println("Starting
Javabug...");

ByteArrayOutputStream baos = new
ByteArrayOutputStream();
ObjectOutputStream oos = new
ObjectOutputStream(baos);

for (int i = 0; i < 1000; i++) {
oos.writeInt(i);
}

baos.flush();

byte[] buf = baos.toByteArray();

ByteArrayInputStream bais = new
ByteArrayInputStream(buf);
ObjectInputStream ois = new
ObjectInputStream(bais);

for (int i = 0; i < 1000; i++) {
System.out.print(i + " ");
int x = ois.readInt();
if (x != i) {
System.out.println
("ERROR : " + i);
}
}

System.out.println("END");
} catch (Throwable t) {
t.printStackTrace();
}
}
}


EXPECTED VERSUS ACTUAL BEHAVIOR :
The given example program about should be able to read back
all 1000 elements.

In ObjectInputStream, the program should recognize the
block header data that was written internally by
ObjectOutputStream onto the stream.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
java.io.EOFException
        at java.io.DataInputStream.readInt(DataInputStream.java:397)
        at java.io.ObjectInputStream$BlockDataInputStream.readInt(ObjectInputStr
eam.java:2645)
        at java.io.ObjectInputStream.readInt(ObjectInputStream.java:892)
        at Javabug.main(Javabug.java:25)

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
import java.io.*;

public class Javabug
{
public static void main(String args[]) {
try {
System.out.println("Starting Javabug...");

ByteArrayOutputStream baos = new ByteArrayOutputStream();
ObjectOutputStream oos = new ObjectOutputStream(baos);

for (int i = 0; i < 1000; i++) {
oos.writeInt(i);
}

baos.flush();

byte[] buf = baos.toByteArray();

ByteArrayInputStream bais = new ByteArrayInputStream(buf);
ObjectInputStream ois = new ObjectInputStream(bais);

for (int i = 0; i < 1000; i++) {
System.out.print(i + " ");
int x = ois.readInt();
if (x != i) {
System.out.println("ERROR : " + i);
}
}

System.out.println("END");
} catch (Throwable t) {
t.printStackTrace();
}
}
}

---------- END SOURCE ----------
(Review ID: 158451)
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