This allows a read-only database to be distributed as a single
file instead of as multiple files within a directory and to be compressed.
In fact, a jar or zip file can contain any number of Derby databases
and can also contain other information not related to Derby,
such as application data or code.
You cannot store the derby.properties file
in a jar or zip file.
To create a jar or zip file containing one or
more
Derby databases:
- Create a database for use on read-only media.
- From the directory that contains the database folder, archive the database
directory and its contents. For example, for the database sales that
lives in the system directory C:\london, issue the command from london.
Do not issue the command from inside the database directory itself.
For example, archive the database folder and its contents using
the JAR program from the JDK. You can use any zip or jar tool to generate
the archive.
This command archives the database directory
sales and
its contents into a compressed jar file called
dbs.jar.
cd C:\london
jar cMf C:\dbs.jar sales
You can add multiple databases
with jar. For example, this command puts the
sales databases and the
boiledfood database
(in the subdirectory products) into the archive.
cd C:\london
jar cMf C:\dbs.jar sales products\boiledfood
The relative
paths of the database in the jar need not match their original relative paths.
You can do this by allowing your archive tool to change the path, or by moving
the original databases before archiving them.
The archive can be compressed
or uncompressed, or individual databases can be uncompressed or compressed
if your archive tool allows it. Compressed databases take up a smaller amount
of space on disk, depending on the data loaded, but are slower to access.
Once
the database is archived into the jar or zip file, it has no relationship
to the original database. The original database can continue to be modified
if desired.
