Native JDBC driver access

[Jakub Kotowski]

Hi,

I'm using PostgreSQL and I need to use some of the PostgreSQL-specific
JDBC extension (such as geometric types). So far I've learned that the
normal simple approach (getting a connection and casting it to
PGConnection) is not possible because with JPA2 it is impossible to
get to the original implementation - I always get only Proxys and a
ClassCastException. It's probably the same with using the C3P0
directly (I know there is some "reflective" way that the C3P0 provides
for accessing native features but I find it not very nice).

I guess what I could do is to write my own "PostgreSQLDBPlugin" that
would create a native PostgreSQL DataSource. If I do this, how should
I use it along with the Play's DBPlugin? Is there a way to switch the
plugin off? Or should my plugin run after the Play's plugin and just
set the DB.datasource again?

Is there some other way of using database-specific features while not
abandoning JPA?

Regards,

Jakub

[Rakesh Waghela]

Checkout http://jooq.org  which is specifically developed to gain advantage of database specific features while maintaining the good accessibility.

[Jakub Kotowski]

Hi Rakesh,

thanks for the pointer, JOOQ looks certainly interesting but I don't
see how it helps to solve my current problem. I'll keep it in mind in
case I rewrite my application one day.

Regards,

Jakub


On Sep 24, 7:38 pm, Rakesh Waghela <javain...@gmail.com> wrote:
> Checkouthttp://jooq.org which is specifically developed to gain advantage

[Jonas]

You can use JDBC directly:

Connection conn = play.db.DB.getConnection()

/Jonas

[Jakub Kotowski]

no, this way you get only a proxy wrapped around the original driver
implementation. Try:

Connection conn = play.db.DB.getConnection()
PGConnection pgconn = (PGConnection) conn; //or whatever JDBC driver
you use

and you'll get a ClassCastException.

[Adam Hooper]

How about "PGConnection pgconn = conn.unwrap(classOf[PGConnection])"?

Enjoy life,

Adam

[Adam Hooper]

How about I write that properly:

Java: PGConnection pgconn = conn.unwrap(PGConnection.class)

Scala: pgconn : PGConnection = conn.unwrap(classOf[PGConnection])

Evidently, I haven't tested either :).

Enjoy life,

Adam

[Jonas K]

On Wednesday, October 24, 2012 6:31:58 PM UTC-4, Adam Hooper wrote:

How about I write that properly:

Java: PGConnection pgconn = conn.unwrap(PGConnection.class)

Scala: pgconn : PGConnection = conn.unwrap(classOf[PGConnection])

For me the above results in 

PSQLException: Method org.postgresql.jdbc4.Jdbc4Connection.unwrap(Class<T>) is not yet implemented. (AbstractJdbc4Connection.java:163)

 

conn match {

  case bcpConn: com.jolbox.bonecp.ConnectionHandle => {

     bcpConn.getInternalConnection() match {

       case pgConn: org.postgresql.PGConnection => {

          val loMgr = pgConn.getLargeObjectAPI()

           ...

       }

       case _ => // handle bad cast

    }

   case _ => // handle bad cast

 }

Seems to work

_jonas

 

 

[ennala]

Hi Jonas,

can you write that code in java.
I am facing the same situation but I was not able to understand you code.

Thanks.