A convinient way to produce output with different verbosity levels is to use the slf4j logging library. Its already included as a maven dependency so you dont have to worry about it. Simply import these two classes
import org.slf4j.Logger; import org.slf4j.LoggerFactory;
and you’re good to go.
final Logger log = LoggerFactory.getLogger(YourProcessor.class);
//for very verbose output that helps you debug your code
log.debug("message");
//in case an error happens. usually means you want to cancel the stream and inform the user of the error
log.error("message");
//display some useful information to the user
log.info("message");
// a warning message. For recovarable errors and such.
log.warn("message");
You’ll find the settings to controll the logging output in
/facttools/src/main/resources/log4j.properties
Some more information about these settings can be found here