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Re: Logging Question

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On Sun, 1 Jan 2012, Arved Sandstrom wrote:

> On 12-01-01 08:59 AM, Jeff Higgins wrote:
>> On 01/01/2012 06:33 AM, Stefan Ram wrote:
>>> Novice<novice@example..com>  writes:
>>>> Yes! I simply copied XMLFormatter from the Java source file, added one
>>>
>>>    A log file should remain usable even when the process was terminated
>>>    abnormally. But an XML file needs to have one single root element
>>>    that has an end tag at its end. A process that is being terminated
>>>    abnormally might not write such an end tag. So, one has no guarantee
>>>    that the log output is well-formed XML. Or did I miss something?
>>
>> Only that there are no guarantees.
>> <http://docs.oracle.com/javase/7/docs/technotes/guides/logging/overview.html#a1.12>
>
> And let's face it, the <log> document element in this case is useless. 
> It conveys zero information. It would better to regard each record as a 
> separate well-formed XML document, and the file is merely physical 
> storage for a bunch of log records.

What happens if you throw such a file into a normal XML parser?

I would imagine that if you're using StAX, you can stop parsing when you 
hit the end of a root element, and then either carry on to the next one, 
or perhaps wrap a fresh parser round the underlying input stream.

I have no idea what a SAX parser would do; i don't know how much 
well-formedness checking they do.

What would a DOM parser do?

You might need to interpolate a layer between the parser and the 
FileInputStream to notionally split the file into substreams, one per 
document. That would require some sort of framing format for the file, i 
think.

> This kind of XML "wrapper" element, as in <log> in this case, happens 
> when folks think that 1 XML document == 1 physical file. An XML document 
> entity is a logical, not a physical storage, concept.

Well, it is physical (quoth the spec: "Each XML document has both a 
logical and a physical structure."), but it's a physical thing distinct 
from a file, and doesn't have to map directly on to it. The spec says "A 
data object is an XML document if ..." and "A textual object is a 
well-formed XML document if ...", but never gets any more specific than 
that.

tom

-- 
I heard this from two different reliable sources on newsgroups. --
Peter Olcott

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Thread

Logging Question Novice <novice@example..com> - 2011-12-31 21:27 +0000
  Re: Logging Question Jeff Higgins <jeff@invalid.invalid> - 2011-12-31 17:25 -0500
    Re: Logging Question Novice <novice@example..com> - 2012-01-01 01:46 +0000
  Re: Logging Question Lew <lewbloch@gmail.com> - 2011-12-31 14:53 -0800
    Re: Logging Question Novice <novice@example..com> - 2012-01-01 01:59 +0000
      Re: Logging Question Jeff Higgins <jeff@invalid.invalid> - 2011-12-31 22:14 -0500
        Re: Logging Question Novice <novice@example..com> - 2012-01-01 05:44 +0000
          Re: Logging Question Jeff Higgins <jeff@invalid.invalid> - 2012-01-01 07:59 -0500
            Re: Logging Question Jeff Higgins <jeff@invalid.invalid> - 2012-01-01 08:14 -0500
            Re: Logging Question Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-01 19:06 -0400
              Re: Logging Question Jeff Higgins <jeff@invalid.invalid> - 2012-01-01 18:24 -0500
              Re: Logging Question Tom Anderson <twic@urchin.earth.li> - 2012-01-03 15:33 +0000
                Re: Logging Question Jeff Higgins <jeff@invalid.invalid> - 2012-01-03 11:21 -0500
                Re: Logging Question Jeff Higgins <jeff@invalid.invalid> - 2012-01-03 11:35 -0500
                Re: Logging Question Tom Anderson <twic@urchin.earth.li> - 2012-01-04 14:42 +0000
                Re: Logging Question Jeff Higgins <jeff@invalid.invalid> - 2012-01-04 11:43 -0500
                Re: Logging Question Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-04 20:28 -0400
                Re: Logging Question Donkey Hottie <donkey@fredriksson.dy.fi> - 2012-01-05 11:28 +0200
                Re: Logging Question Tom Anderson <twic@urchin.earth.li> - 2012-01-08 14:08 +0000
                Re: Logging Question Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-09 19:47 -0400

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