Log SQL Statements With Parameter Values Filled In (Spring JDBC)

If you’re using parameterized queries with Spring JDBC (and why wouldn’t you?), it’s easy to log them with a simple log.debug() statement. But your logged statements will be full of ?’s instead of the values, which makes them much less useful. Suppose you’d like to know what was substituted for those question marks. It’s not so difficult if you use AspectJ.  Here is what is needed:

1. aspectjrt.jar and aspectjweaver.jar from here.
2. An aspect with a pointcut on the JdbcOperations interface, which JdbcTemplate implements.
3. @Before advice that intercepts the execution of JdbcTemplate methods and logs de-parameterized SQL statements.
4. Configuration of Spring applicationContext.xml to get it working.

Let’s start off with our class:

@Aspect
public class SqlLogger {
    private static final Logger log = LoggerFactory.getLogger(SqlLogger.class);

Here, I’m using an org.slf4j.Logger, but any logging framework will work.

Next step is to add the method that will capture the SQL and parameters as they are executed. Again, I’m using Spring JDBC, so all calls are made to an object that implements JdbcOperations.  We can set up our class to spy on all relevant calls by defining our method like so:

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