Can we be done loading driver and registering driver by Using 'new" Operat.

Question

Dear Sir..
Can we directly create the instance of any driver class by using the "new" operator and by this object can we call any method like getConnection() etc,will it return connection instance.
Is it necessary these all task from loading to registering the drivers all done by the help of class.forName().
Please i am very confuse ...help me..

Answer 1

The JDBD API is an early (and consequently rather clumsy) example of a pattern which I call the Factory/Interface pattern (not an official name).
The idea is to allow different implementations of an API where the implentation actually used doesn't need to be known at compile time. Another example of this pattern is the SAX and DOM xml parsers. JNDI is a third example.
You wouldn't normally even have the database driver library on your classpath when compiling, so you avoid referring to the concrete Driver instance as a class reference, in the FQN of the concrete driver class is likely to be part of a configuration file.
If it were being designed today I don't doubt that the implementing class names would be contained in the services directory of the jars containing them and you wouldn't need to know their names at all, all the drivers on the class path would take a look at the URL until one accepted it.
It's a nice idea, but with JDBC the actual benefits probably aren't all that great, particularly when different vendors have different flavours of SQL.
By the way. when a driver class is loaded it registers itself with the DriverManager as part of it's class initialization code (in a static initializer), so if you do create an instance the class registers itself automatically.
You can use the Driver classes directly, I've had to do this on one occasion because I was loading the Driver from a URLClassLoader and DriverManager won't deliver drivers that have a different classloader from the class that calls getConnection().