You can set properties programmatically -- either in application code before
booting the driver or
as a command-line option to the Java Virtual
Machine (JVM) when booting the application that starts up
. When you set
properties programmatically, these properties persist only for the duration of
the application. Properties set programmatically are not written to the
derby.properties file or made persistent in any other way by
.
Setting properties programmatically works only for the application that
starts up ; for example,
for an application in an embedded environment or for the application server that
starts up a server product. It does not work for client applications connecting
to a server that is running.
You can set properties programmatically in the following ways:
As a parameter to the JVM command line
You can set system-wide properties as parameters to the JVM command line when
you start up the application or framework in which
is embedded. To do so,
you typically use the -D option. For example:
java -Dderby.system.home=C:\home\\
-Dderby.storage.pageSize=8192 JDBCTest
Using a Properties object within an application or statement
In embedded mode, your application runs in the same JVM as
, so you can also set
system properties within an application using a Properties object before
loading the JDBC
driver. The following example sets derby.system.home on Windows.
Properties p = System.getProperties();
p.setProperty("derby.system.home", "C:\databases\sample");
If you pass in a Properties object as an argument to the
DriverManager.getConnection call when connecting to a database, those
properties are used as database connection URL attributes, not as properties of
the type discussed in this section. For more information, see
and
as well as the
.