openConnection stepthrough

1. Class.forName(JDBC_DRIVER); This loads the JDBC embedded driver class for Derby. Specifically the relevant is in the initialization functions for the class org.apache.derby.jdbc.EmbeddedDriver
2. conn = DriverManager.getConnection(DATABASE_URL_OPEN); This actually opens up the driver.
3. Error handling. Errors are caught and logged. Note that errors are logged rather than stopping the program or retrying; this function might return null because of an error. Calling methods should be able to handle this.

Note that no more than one connection should be open at once.