Basically, you just have to replace your jdbc connection
string with:

jdbc:log:real_driver_class:real_jdbc_connection_string

So, if your jdbc connection string was:

jdbc:oracle:thin:@localhost:1521:FOOBAR
it would become:
jdbc:log:com.oracle.jdbc.OracleDriver:oracle:thin:@localhost:1521:FOOBAR

or something like that.  Once you have done that, you can use log4j to
log anything you want to know from your jdbc driver.  Currently I am
logging basic connection operations, statement execution, and
preparedStatement execution (with bind parameters).  There are two
ways to log the bind parameters.  The first is the default:

DEBUG [main] (LogPreparedStatement.java:64) - executing
PreparedStatement: 'select * from ECAL_USER where login like ?' with
bind parameters: {1=%rbb%}

(The %s are a part of the string)  Notice that I have left the ?s in
the sql statement, and I let you do the substitution.  The second
option requires you to set a System property, replace.bindParams, to
either true or 1.  That logs:

DEBUG [main] (LogPreparedStatement.java:73) - executing PreparedStatement: selec
t * from ECAL_USER where login like %rbb%

In this case, the bind parameters are in the string.  I am still very
clear that I am logging the PreparedStatement though.

This jdbc driver basically replaces Hibernate's showSQL option and it
is more informative than that option, so I am pretty happy with it.  I
can easily add more logging, and expect to add logging for stored
procedures very very soon (like tomorrow).  Play around with it, and
let me know what you think.  If I find it useful, I am likely to use
this driver as an article topic.

I'll be adding viewcvs to the server soon, so that you can browse the
source that way, and I'll most likely add some real docs too.