Log4J is a reliable, fast and flexible framework written in JAVA to perform logging in Java applications and it is provided by Apache Software Foundation.
- Log4j is able to allow more than one thread at a time without providing data inconsistency, so that, Log4j is thread-safe.
- Log4j will not slow down the application execution, it will be optimized to improve application performance.
- Log4j is providing environment to send logging messages to more than one output appenders.
- Log4j supports internationalization.
- Log4j is providing services for both predefined and user defined facilities, it able to provide some customization’s also.
- Log4j allows to set logging behaviors at run time through the configuration file.
- Log4j is providing very good environment to trace Exceptions from its root.
- Log4j uses multiple levels like ALL, TRACE, DEBUG, INFO, WARN, ERROR and FATAL to generate messages.
- Log4j allows to change the format of log output by extending Layout class.
- Log4j is using appenders to generate log messages.