Name: nt126004 Date: 01/06/2003


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 am no little surprised that this has gone unreported all
these years so I should point out that NEITHER DOWNSTREAM
DECORATORS (OR FILTERS) NOR THE DESTINATION FILE HAVE BEEN
CLOSED. THIS IS NOT A "BROKEN CHAIN" PROBLEM.


Writing to a closed BufferedOutputStream does not throw an
IOException until the byte buffer is full. The reason for
this behavoir is obvious looking at the write methods in
BufferedWriter (by way of comparison). They include a
private ensureOpen() method that throws an IOException
with a detail message of "Stream closed". This method is
missing in BufferedOutputStream. Adding such a method is
not a backwards compatibility issue, and so I am reporting
this as a bug.

The contract of OutputStream.close() claims :
"A closed stream cannot perform output operations and cannot be reopened."

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Compile and execute sample code
2.
3.

EXPECTED VERSUS ACTUAL BEHAVIOR :
*First* write after closing stream should throw IOexception.

REPRODUCIBILITY :
This bug can be reproduced always.

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

public class Test {
    public static void main(String[] args) {
        try {
            byte[] b = { 'a', 'b' };
            byte[] c = { 'c', 'd' };
            OutputStream os = new BufferedOutputStream(
                              new FileOutputStream("out.txt", false));
            os.write(b);
            os.close();
            os.write(c); // this suceeds - bug

            os = new FileOutputStream("out.txt", true);
            os.write(b);
            os.close();
            os.write(c); // crashes here, correct.
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
---------- END SOURCE ----------

CUSTOMER WORKAROUND :
In terms of silently losing data written to a closed
BufferedOutputStream that does not reach its buffer
capacity there is no workaround. Of course, not writing to
closed streams would help.
(Review ID: 179375)
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