Re: JDBC connection to mysql problem
Tom Anderson wrote:
That jar also contains a
META-INF/services/java.sql.Driver
Which should, i believe, be sufficient for DriverManager to load the
driver without a Class.forName call.
Martin Gregorie wrote:
Is it reasonable to assume that any other JDBC driver jar file would be
similar enough to work without needing the Class.forName() call, which is
said not to be harmful even if not needed.
My guess is "no" for "any other JDBC driver [library]", but it is safe for the
major ones. At a minimum, PG, Derby, Oracle and DB2 have 'DataSource' classes
and such.
My experience bears out that the 'Class.forName()' approach is, indeed,
harmless. It depends for its success that drivers are required to register
themselves somehow with the JDBC mechanism upon class initialization.
Presumably they get loaded even via the 'DataSource' mechanisms; you just
don't have to explicitly as for class loading and initialization in that pattern.
As for repeated 'forName()' calls, they're idempotent, so the only costs are a
screwy program structure and redundant method calls.
The former is more serious. If the class-load happens deep in some unrelated
code, and thus likely in more than one place in code, it complicates maintenance.
I'm thinking about writing DB-agnostic code in asking this.
I don't believe in agnosticism, but I'm tolerant of it.
...
...
I /am/ talking about databases!
--
Lew