How to determine what SQL query a java web application is using to return the data?

I have been given a java web application for which I have the source code to. The application queries an Oracle database to return data back to the user in web page. I need to update a value for the returned data in the database, without knowing the table or column names. Is there a general way to determine what query the application is submitting to return the data for a particular page so I can find the right tables and columns?

I am new to java and web development so not sure where to start looking. Thanks!