Re: ClassCastException with LargeObjectAPI and Tomcat Connection

When you use a DataSource, the connection returned is not an
org.postgresql.PGConnection, so the ClassCastException would be expected.
The connection is usually wrapped (though I'd have to look at the Tomcat
impl to be sure) because the behavior is supposed to be different for
pooled connections (in particular, close, and often setAutoCommit).
Now that I look at it, we could easily enough make the PostgreSQL
pooled connections implement PGConnection, and then you could just use the
PostgreSQL DataSource instead of the Tomcat DataSource.

Aaron

On Fri, 3 Jan 2003, Joao Filipe Placido wrote:
> Hello list,
>
> I configured successfully a PostgreSQL 7.2.3 connection pool with JNDI
> DataSource following the Tomcat docs (v 4.1.12).
> But when I try to use the returned connection with the LargeObjectAPI,
> tomcat gives me a ClassCastException (runtime), in the following line:
>
> LargeObjectManager lobj =
> ((org.postgresql.PGConnection)db).getLargeObjectAPI();
>
> I tried using pgjdbc2.jar, in which case instead of
> org.postgresql.PGConnection, it only works with org.postgresql.Connection.
> With pg73jdbc3.jar, and using org.postgresql.PGConnection, the same
> Exception occurs.
> I also tried with a compiled JDBC jar from the 7.3 sources, with no luck.
>
> I don't understand why the connection works with non-LargeObject SQL and
> fails here. I have the same jars working with the LargeObjectAPI without the
> Tomcat DBCP.
> Any help is appreciated. Has anyone successfully configured a tomcat DBCP
> with PostgresSQL and used LOs with it?
>
> Thank you,
>
> João Filipe Plácido
>
>