Re: How can I write values in a properties-File which is located in a JAR without copying the whole JAR?

"Andrew Thompson" <u32984@uwe>
Fri, 17 Aug 2007 09:11:51 GMT
<76d28d9144fd5@uwe> wrote:

I have a question concerning properties-files in Java.

Writing in a properties-file and reading out of the file is working as
long as I don't put my files in a JAR.

The best approach to user here, is to treat the
properties file in the jar as simply an 'initial'
properties file.

Check in "user.home"/our/backward/domain/
for the properties file. If it is not there, read it
from out of the jar, and write it to there.

Proceed loading the property file from the
sub-directory of user.home.

Using this scheme, you can also offer a
'revert properties to defaults' option in the
GUI, by simply retoring them from unchanged
version in the Jar. ;-)

But no, attempts to *edit* or *update* the actual
resource in the Jar file will probably fail, or end
in a very fragile application.

The adventureous part of the programm is that I'm trying to make an
application which should be able to remember user-settings (write
values in properties-file) and load them (read out values of
properties-file) when started next time.

Here is an example of storing user preferences.
It makes use of the web start API's PersistenceService
to do the same basic thing I described above, but for a
sandboxed app. launched using web start (and with no
specific '.properties' file to begin with).

...(The user just has to unzip a ZIP-archive, which includes
a folder with the necessary libraries and a JAR-file with my classes.)

'Tut-tut' - use web start for the launch - much easier
for the end-user.


Andrew Thompson

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