Re: reading data from "journal"-files

peacecop kalmer wrote:

> Is there a way to read the data from an existing .journal-file
> like converting it into XML or CSV or any other human-readable
> format? I have lots of journal-files that has been used for
> storing data and I need this data for further analyses.
> However, I don't have the source code of the application itself
> that uses these journal-files.

The missing source code makes it potentially tricky. Are you at
least able to run the application? And does the application have
an option to trigger a Prevayler snapshot?

Conceptually, the journal files aren't really "storing data" in
the sense of a database table. They are more like a log of
changes, so ideally you would bring up the application, let it
read all the journals, and then get the data you need from the
application's memory. A Prevayler snapshot, as opposed to a
journal, contains a dump of the objects in memory that result
from replaying all the journals.

If you're lucky, the application is already configured to
generate snapshots in XML format. The default is to use Java
serialization, which is less convenient than XML but is at
least a well-defined format that you might be able to figure
out how to process.

Cheers,
Justin



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