java.sql.Driver

The class that loads Derby's local JDBC driver is the class org.apache.derby.jdbc.EmbeddedDriver. Listed below are some of the ways to create instances of that class. Do not use the class directly through the java.sql.Driver interface. Use the DriverManager class to create connections.

If your application runs on JDK 1.6 or higher, you do not need to do any of the following. The EmbeddedDriver will load automatically when your application asks for its first Connection.
Class.forName("org.apache.derby.jdbc.EmbeddedDriver")
Our recommended manner, because it ensures that the class is loaded in all JVMs by creating an instance at the same time.
new org.apache.derby.jdbc.EmbeddedDriver()
Same as Class.forName("org.apache.derby.jdbc.EmbeddedDriver"), except that it requires the class to be found when the code is compiled.
Class c = org.apache.derby.jdbc.EmbeddedDriver.class
This is also the same as Class.forName("org.apache.derby.jdbc.EmbeddedDriver"), except that it requires the class to be found when the code is compiled. The pseudo-static field class evaluates to the class that is named.
Setting the System property jdbc.drivers
To set a System property, you alter the invocation command line or the system properties within your application. It is not possible to alter system properties within an applet.

java -Djdbc.drivers=org.apache.derby.jdbc.EmbeddedDriver
    applicationClass

The actual driver that gets registered in the DriverManager to handle the jdbc:derby: protocol is not the class org.apache.derby.jdbc.EmbeddedDriver; that class simply detects the type of Derby driver needed and then causes the appropriate Derby driver to be loaded.

The only supported way to connect to a Derby system through the jdbc:derby: protocol is using the DriverManager to obtain a driver (java.sql.Driver) or connection (java.sql.Connection) through the getDriver and getConnection method calls.