OK, so I must deploy my container a ressource file where all needed data
is specified to connect to my MySQL server/database. Then I make a
dataSource with an abstract type DataSource which is fetched via JNDI
from my ressource file (I don't know which type it has - e.g.
MySQL/PostgreSQL/... because I'm using an abstract type). This
dataSource is given to my constructor and it should work? (so, it's
something like a "workaround" :D )
In fact, I can use the Maven Jetty WebServer too if am able to deploy a
valid ressource file and can include the MySQL Connector/J or I can make
mvn package in the taste-web folder and copy the war file to an other
container (e.g. Tomcat) to work with this file.
Am 16.02.2011 16:27, schrieb Sean Owen:
You do not need to use the Connector/J classes directly, and shouldn't.
Yes, you need a DataSource. If you're inside a web container, then you
can and should already have configured the database connection in the
container's configuration file. It makes the DataSource available for
lookup via JNDI.
At no point do you need to know that the DataSource is actually a
MysqlDataSource in your code, no.
I think you need to read that Tomcat page and understand how J2EE
containers deal with DataSources via JNDI. It will be clearer. This is
not specific to Mahout.
2011/2/16 Daniel Mühlbachler<[email protected]>:
yeah, that's what I meant. My problem is that I am importing the MySQL
Connector/J directly in my source file.
So all my source files are not allowed to use such a class? But the
MySQLJDBCDataModel has a constructor like ...(DataSource ds, ...) and
DataSource is provided by the MySQL Connector/J but how can I give my
constructor a dataSource if I can't use the classes I need - deps that
shouldn't be there?
Moreover, if I can configure the jetty server that it can handle MySQL
connections it's also ok but how can I compile a java source file that needs
a dataSource which is declared in a class I can't use directly? (something
paradox...)
Am 16.02.2011 16:13, schrieb Sean Owen:
No. As I've said, you never import the driver / connector classes
directly. You have a complete working example: Mahout. As you can see
it doesn't depend on this.
As I've also said, please read the documentation for Tomcat (or your
container). Here you go:
http://tomcat.apache.org/tomcat-6.0-doc/jndi-resources-howto.html#JDBC_Data_Sources
This is where MySQL Connector/J is involved.
2011/2/16 Daniel Mühlbachler<[email protected]>:
ok, thanks for your detailed answer - now I understand! :)
So my problem is that I must import the MySQL Connector/J into my source
files because I need them. The nasty thing about that is that I just need
"import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;" in my dataSource
but
that won't work because there shouldn't be any dependencies on that
because
I must configure the web application to use/provide the connector.
omg... Is there any example round here that shows such a configuration?
