Re: BufferedWriter.write does not throw exception if it is already closed.

[Jing LV]

Thanks for reply Alan, sorry didn't see this mail before I raise an 
issue on https://bugs.openjdk.java.net/show_bug.cgi?id=100169 (my mail 
server seems some problem these days)

Consider it is using underlying writer, one thing I need to mention is 
that in the testcase I post in the first mail, it was trying to throw an 
exception[1] in its write method when it's closed already. I am ok with 
the documentation modification myself, however I wonder it may confuse 
customer if he found his own writer has no problem at all?

[1]
@Override
public void write(char[] buf, int offset, int count) throws
IOException {
        if (closed) {
                throw new IOException("Already closed");
        }
}



于 2011-1-28 18:55, Alan Bateman 写道:
Jing LV wrote:
Hi Alan,

(Sorry for late reply that it seems my mail-box has some trouble that 
I cannot send my mail yesterday). I agreed with you that the document 
may be changed. However as you see another problem is that the write 
method is unstable, it may or may not throw the exception, only 
depends on its buffer size, I think we'd better at least fix this 
unpredictable behaviour?

I think this is part of the same issue. BufferedWriter#close is 
failing because the underlying Writer's close is failing. This leaves 
the BufferedWriter "open" and the underlying Writer "closed". If you 
continue writing then the BufferedWriter may continue to buffer 
characters but if it has to flush to the underlying Writer then it 
will fail. This is clearly undesirable and it may be best to clarify 
the spec so that stream will be considered to be closed even if the 
close fails (as the current behavior is long standing behavior we 
would just need to think through any implications/side-effects). We 
can easily the implementation too, and in addition the suppressed 
exception support gives us the opportunity to fix a few other issues 
in these classes. I'll create a bug for this today.

-Alan.