log4j.rootLogger=DEBUG, ConsoleAppender log4j.appender.ConsoleAppender=org.apache.log4j.ConsoleAppender log4j.appender.ConsoleAppender.layout=org.apache.log4j.PatternLayout log4j.appender.ConsoleAppender.layout.ConversionPattern=[%d{yyyy-MM-dd HH:mm:ss}] [%-5p] %C{1}.%M(%L) - %m%n import org.apache.log4j.Logger; public class MyClass { private static final Logger logger = Logger.getLogger(MyClass.class); public void doSomething() { logger.debug("This is a debug message."); logger.warn("This is a warning message."); try { throw new Exception("Something went wrong."); } catch (Exception e) { logger.error("An error occurred: " + e.getMessage(), e); } } }