Name: rmT116609			Date: 02/06/2003


FULL PRODUCT VERSION :
java version "1.4.1"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1-b21)
Java HotSpot(TM) Client VM (build 1.4.1-b21, mixed mode)

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

A DESCRIPTION OF THE PROBLEM :
As shown in the example code, "file" URLs can't be written
to.  There are work-arounds, but they suffer from
limitations.  Adding custom handling for the "file" protocol
defeats the purpose of the abstraction we are trying to hide
behind.  Adding an enhanced protocol handler seems workable,
but the case for this being supported "out-of-the-box" is
pretty strong.  It would be different if the protocol was
rarely used or had issues with output semantics.  Neither is
true.

Whether or not any behavior is changed, additional
documentation is needed about what protocols are supported
by the default handlers.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Create a File URL
2. Open it
3. Try to get an OutputStream

EXPECTED VERSUS ACTUAL BEHAVIOR :
Expected:
FileURLConnection should support output.
Failing that, it should throw an
UnsupportedOperationException when setDoOutput(true) is invoked.

Actual:
An UnknownServiceException is thrown when getOutputStream()
is invoked.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
d:\DOCUME~1\ccox\LOCALS~1\Temp\foo31795bar can be written to true
Exception in thread "main" java.net.UnknownServiceException: protocol doesn't
support output
        at java.net.URLConnection.getOutputStream(URLConnection.java:679)
        at Test.main(Test.java:13)

REPRODUCIBILITY :
This bug can be reproduced always.

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

public class Test {

public static void main(String[] args)
    throws Exception
{
   File file = File.createTempFile("foo","bar");
   System.out.println(file + " can be written to " + file.canWrite());
   URLConnection con = file.toURL().openConnection();
   con.setDoOutput(true);
   PrintWriter out = new PrintWriter(con.getOutputStream());
   out.write("Test");
   out.close();
}

}
---------- END SOURCE ----------

CUSTOMER WORKAROUND :
Either
a) Add special handling for file URLs or
b) Install a protocol handler

See the following for discussion:
http://forum.java.sun.com/thread.jsp?forum=31&thread=290300
(Review ID: 180944) 
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