Back to Lessons

Java Logging Framework

April 5, 2026

Logging API

Record application events for debugging and monitoring.

Logging Example

import java.util.logging.*;

Logger logger = Logger.getLogger(MyClass.class.getName());
logger.setLevel(Level.INFO);

logger.info("Application started");
logger.warning("Low memory detected");
logger.severe("Critical error occurred");

ConsoleHandler handler = new ConsoleHandler();
handler.setFormatter(new SimpleFormatter());
logger.addHandler(handler);

Key Points

  • Levels: SEVERE, WARNING, INFO, CONFIG, FINE, FINER, FINEST.
  • Handlers: ConsoleHandler, FileHandler.
  • Formatters control log output format.
  • Configuration via logging.properties.
Previous Lesson End of course