JUL vs. Log4j

JUL (Java Util Logging) vs. Log4j

Similarities

• Log4j and JUL are almost conceptually identical.
  But JUL renamed some concepts : For example appenders are "handlers," layouts are "formatters," and LoggingEvents are "LogRecords"
• JUL uses log levels the same way that Log4J uses levels.
  Although JUL has 9 default levels instead of 7
• JUL organizes loggers in a hierarchy and JUL loggers inherit properties from their parent loggers.
  Same way Log4j organizes its loggers.

Differences

• JUL uses API java.util.logging
• Log4j uses API org.apache.commons.logging
  

• JUL has Unclear log levels :
  SEVERE - WARNING - INFO - CONFIG - FINE - FINER - FINEST 
• Log4j has Clear log level using different names :
  FATAL - ERROR - WARN - INFO - DEBUG - TRACE
  

• No ERROR level in JUL
• There is an ERROR level in Log4j
  

• To log an exception in JUL, it is unclear what Level to use and why do I need to pass e.getMessage() parameter, Like :
  logger.log(Level.SEVERE, e.getMessage(), e);
• Simpler logging syntax in Log4j, Like
  logger.error(e);
  

• In JUL, there is no way to put a configuration in the classpath to be automatically picked up by the logging framework.
  To configure either modify the logging.properties in your JRE/lib folder
  OR 
  Set JVM parameter -Djava.util.logging.config.file=/my/folder/logging.properties
• In Log4j, there is a possibility to put an already configured configuration file.
  

• Another method to create a logger is missing in JUL, Like : 
  Logger.getLogger(class)
  
  Method to create logger is :
  private static Logger logger =
            Logger.getLogger(MyCLass.class.getName());
  
• Log4j has method to create a logger with syntax : 
  private Logger logger = Logger.getLogger(getClass());