> I use conn.isValid(2000) in my code and get a crash at that line, with
> this exception:
>
> SEVERE: Servlet.service() for servlet jsp threw exception
> java.lang.AbstractMethodError:
> org.apache.tomcat.dbcp.dbcp.PoolingDataSource$PoolGuardConnectionWrapper.isValid(I)Z
> at lu.demo.web.Application.getDbConnection(Application.java:49)
>
> Still being a little newbie... do I do something wrong?

Most likely you run Java 6.0, but use JDBC driver version for Java 5.0
or 1.4.2.

Roman