Re: Storing preprocessed data over executions

RedGrittyBrick <>
Fri, 04 Apr 2008 15:13:06 +0100
Hendrik Maryns wrote:


I have a simple program that queries a 2?tree bank2". This is a text file
containing descriptions of linguistic trees. To make the querying
efficient, the data is proprocessed into a binary format. This is
stored somewhere on disk, and used by other parts of the program.

At this point, the binary data is stored in the place where the original
file is, with another file ending. This solution is unsatisfactory,
since the directory in question might not be writable. So I want to
store the preprocessed tree banks somewhere in a directory for my
program. Furthermore, I2"d like to have access to them in a subsequent
execution of the program, since this preprocessing step is quite
intensive and there is no need to do it each time. Also, some other
file are generated during execution and they can be put there as well;
and I want to have a 2?cleanup2" option to delete them.

How is this handled generally in Java?

In Linux, one would make a directory .<programname> in the user2"s home
directory and store data there. There is no such thing as a workspace
where this data can be stored, like Eclipse does.

I could of course ask the user to choose a directory at startup, but
that is sub-optimal.

What I am trying now is to create a temp dir and store stuff there, but
that does not persist between executions, since a new temp dir is
created each time.

Here's what I do to persist application-specific settings:

   if ("Windows XP".equals(System.getProperty(""))) {
      propertiesPath = System.getProperty("user.home")
                     + System.getProperty("file.separator")
                     + "Application Data"
                     + System.getProperty("file.separator")
                     + developerName;

      boolean success = (new File(propertiesPath)).mkdir();
      propertiesFileName = propertiesPath
                         + System.getProperty("file.separator")
                         + appName + ".properties";
    } else {
      propertiesPath = System.getProperty("user.home");
      propertiesFileName = propertiesPath
                         + System.getProperty("file.separator")
                         + "." + appName + ".properties";

But obviously this needs some attention :-)


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