It would be great if you could open a Jira issue for this with the explanation
below. It would also be great if you could provide a patch to fix the problem.
Ralph
On Feb 20, 2010, at 6:37 AM, Ronan KERDUDOU - VirageGroup wrote:
> Hi,
>
>
>
> Here is a serious issue in the
> org.apache.commons.vfs.util.MonitorInputStream (and so it is also in
> org.apache.commons.vfs.provider.DefaultFileContent$FileContentInputStream)
>
>
>
> FileContentInputStream extends MonitorInputStream extends
> BufferedInputStream
>
> So they support < mark > (stream.markSupported() returns true)
>
>
>
> But in MonitorInputStream.read(), when reaching the end of the stream, there
> is a call to close() regardless if 'mark' is positioned.
>
> To respect BufferedInputStream specifications we shouldn't close the stream
> in order to be able to call reset() on the stream and return in the state i
> twas when we called mark().
>
>
>
> Usually doing the folowing before using mark feature :
>
> if (!stream.markSupported()) {
>
> stream = new BufferedInputStream(stream);
>
> }
>
> Won't work with a VFS stream.
>
>
>
> So what i did :
>
> if (!stream.markSupported() || stream instanaceof
> MonitorInputStream) { //Hack to solve a VFS issue
>
> stream = new BufferedInputStream(stream);
>
> }
>
>
>
> I inform you also that in the BufferedInputStream.close() doc, it'written :
>
> < Once the stream has been closed, further read(), available(), reset(), or
> skip() invocations will throw an IOException. >
>
> And in the MonitorInputStream, if we call read() after close() it returns
> '-1'.
>
>
>
> Thank you in advance for solving this issue (may be somewhat difficult not
> to break compatibility with code that uses this specific usage)
>
>
>
> IMHO,
>
> I think < end-of-stream monitoring > doesn't mean < close when reach the end
>> but should mean < propose a way to execute some code when reaching the end
>> but anyway if we put a call to close() in this code it breaks the
> habillity to call reset().
>
> As this class consequently modify the comportment from the super class it
> should be more documented and explain what it does.
>
> I would say that your class is currently doing end-of-stream autoClose and
> after-close monitoring.
>
> Maybe it shouldn't extends BufferedInputStream to avoid confusion and don't
> try to support 'mark' (respond false in markSupported()) as it doesn't seem
> to serve you.
>
>
>
> Regards,
>
>
>
> KERDUDOU Ronan
>
> VIRAGE Group (France)
>
> +33 2 53 55 10 22
>
> [email protected]
>
> www.viragegroup.com <http://www.viragegroup.com/>
>
>
>
>
>
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