class.forName vs DriverManager.registerDriver

[Debabrata Jana]

Dear Friend
Please explain the topic---

which one is better to use class.forName or DriverManager.r egisterDriver at the time when we want to get a connection with database.
Please explain it..


And please also explain which one is dynamic?

Thanks and regards

Debabrata

[r035198x]

Dear Friend
Please explain the topic---

which one is better to use class.forName or DriverManager.r egisterDriver at the time when we want to get a connection with database.
Please explain it..


And please also explain which one is dynamic?

Thanks and regards

Debabrata

Class.forName() registers the JDBC driver by calling DriverManager.r egisterDriver() . It also creates an instance of the driver. There is no need to call DriverManager.r egisterDriver() unless of course you are writing the driver itself.

[dmjpro]

Dear Friend
Please explain the topic---

which one is better to use class.forName or DriverManager.r egisterDriver at the time when we want to get a connection with database.
Please explain it..


And please also explain which one is dynamic?

Thanks and regards

Debabrata

What do you mean by Dynamic?
Be specific.

Kind regards,
Dmjpro.

[JosAH]

Class.forName() registers the JDBC driver by calling DriverManager.r egisterDriver() . It also creates an instance of the driver. There is no need to call DriverManager.r egisterDriver() unless of course you are writing the driver itself.

Class.forName() doesn't do anything like that, it just loads the mentioned class.
Some JDBC drivers register themselves when their static { ... } class initialization
code is invoked; other JDBC drivers don't do that and you have to register such
driver yourself. Note that both these variants are outdated (see the API docs).

kind regards,

Jos

[r035198x]

Class.forName() doesn't do anything like that, it just loads the mentioned class.
Some JDBC drivers register themselves when their static { ... } class initialization
code is invoked; other JDBC drivers don't do that and you have to register such
driver yourself. Note that both these variants are outdated (see the API docs).

kind regards,

Jos

Of course Class.forName when called simply loads the mentioned class, but when called on a driver class the static initializer of that class would then perform the other actions I was talking about. So in the context of drivers and when comparing Class.forName with DriverManager.r egisterDriver .... ugh, I'm just trying to defend myself here ....

From this page they have :

"All Driver classes should be written with a static section (a static initializer) that creates an instance of the class and then registers it with the DriverManager class when it is loaded.
....


A Driver class is loaded, and therefore automatically registered with the DriverManager, in one of two ways:

1. by calling the method Class.forName. This explicitly loads the driver class. Since it does not depend on any external setup, this way of loading a driver is the recommended one for using the DriverManager framework. The following code loads the class acme.db.Driver:

Class.forName(" acme.db.Driver" );

If acme.db.Driver has been written so that loading it causes an instance to be created and also calls DriverManager.r egisterDriver with that instance as the parameter (as it should do), then it is in the DriverManager's list of drivers and available for creating a connection.
.....
"

[JosAH]

No need to defend yourself, I wasn't attacking you ;-) That JDBC framework went
through a bit of evolution too and nowaday drivers are required to register themselves.
In the 'old' days it was up to the vendor how you were supposed to get their driver
registered. Nowadays we have DataSources so we have to go through all those
new hoops to get to our own data ;-)

kind regards,

Jos

[r035198x]

No need to defend yourself, I wasn't attacking you ;-) That JDBC framework went
through a bit of evolution too and nowaday drivers are required to register themselves.
In the 'old' days it was up to the vendor how you were supposed to get their driver
registered. Nowadays we have DataSources so we have to go through all those
new hoops to get to our own data ;-)

kind regards,

Jos

Did they really get the DataSources idea from M$ or was that somewhere in the road map?

[JosAH]

Did they really get the DataSources idea from M$ or was that somewhere in the road map?

I really don't know; I noticed that funny thing when I noticed a similar DataSource
way of installing your driver in the Apache project. It has to do with how the JNDI
stuff got popular; not sure though ... I'm not a database fanatic ;-)

kind regards,

Jos