If the application that started the embedded quits
but leaves the Java Virtual Machine (JVM) running, continues
to run and is available for database connections.
In an embedded system,
the application shuts down the system
by issuing the following JDBC call:
DriverManager.getConnection("jdbc:derby:;shutdown=true");Shutdown
commands always raise SQLExceptions.
When a system
shuts down, a message goes to the log file:
----------------------------------------------------------------
Thu Sep 13 09:53:21 EDT 2012: Shutting down Derby engine
----------------------------------------------------------------
Thu Sep 13 09:53:21 EDT 2012:
Shutting down instance a816c00e-0139-bfe6-bff8-000000a155b8 on
database directory C:\sampledb with class loader
sun.misc.Launcher$AppClassLoader@9931f5
----------------------------------------------------------------
If you are running with a security manager on JDK 8 or higher, you must grant
permission to
deregister the embedded driver in order to fully shut down the system. See
"Configuring Java security" in the
for details.
Typically,
an application using an embedded engine
shuts down just before
shutting itself down. However, an application can shut down and
later restart it in the same JVM session. To restart successfully,
the application needs to reload org.apache.derby.jdbc.EmbeddedDriver
explicitly, as follows:
Class.forName("org.apache.derby.jdbc.EmbeddedDriver").newInstance();
This is an exception to the rule that you do not need to load the driver
explicitly when starting
.
The JDBC specification does not recommend calling
newInstance(), but adding a newInstance() call
guarantees that will be
booted on any JVM.
If your application will need to restart
, you can add the
attribute deregister=false to the connection URL to avoid having to
reload the embedded driver:
DriverManager.getConnection("jdbc:derby:;shutdown=true;deregister=false");
It is also possible to shut down a single database instead of the entire system. See .
You can reboot a database in the same session
after shutting it down.