Apache Log4j version 2.

Overview

Apache Log4j version 2.

Example 

  private static final Logger log = LoggerFactory.getLogger(MyClass.class);
log.info("Processing order {}", orderId);

Common Use Cases

  • Production debugging
  • Performance monitoring
  • Incident response

Pitfalls to Avoid

  • Logging sensitive data (PII, passwords)
  • Excessive DEBUG logging in production
  • Spring Boot Actuator
  • Distributed tracing

Best Practices

  • Understand when to use log4j2 versus simpler alternatives
  • Write unit tests covering edge cases and failure paths
  • Follow Java conventions and prefer standard library APIs when available
  • Profile before optimizing — measure impact in your specific workload