Java logging framework

Java logging framework

Framework	Supported log levels	Standard appenders	Popularity	Cost / licence
Log4J	FATAL ERROR WARN INFO DEBUG TRACE	AsyncAppender, JDBCAppender, JMSAppender, LF5Appender, NTEventLogAppender, NullAppender, SMTPAppender, SocketAppender, SocketHubAppender, SyslogAppender, TelnetAppender, WriterAppender	Widely used in many project and platforms	Apache License, Version 2.0
Java Logging API	SEVERE WARNING INFO CONFIG FINE FINER FINEST	Depends on the underlying framework; Sun's default Java Virtual Machine (JVM) has the following: ConsoleHandler, FileHandler, SocketHandler, MemoryHandler	Not widely used[citation needed]	Comes with the JRE
Apache Commons Logging	FATAL ERROR WARN INFO DEBUG TRACE	Depends on the underlying framework	Widely used, in conjunction with log4j	Apache License, Version 2.0
SLF4J	ERROR WARN INFO DEBUG TRACE	Depends on the underlying framework, which is pluggable	Probably small but growing	MIT License