Log4j is an open source project for Apache. By using Log4j, the destination of log information can be controlled by the console, file, GUI component, or even socket server, NT event logger, UNIX Syslog Daemon. You can also control the output format of each log; by defining the level of each log information, you can more carefully control the log generation process. Most interesting is that these can be configured flexibly through a configuration file without having to modify the application code.
Apache Log4j is a well known framework for logging application behavior. Log4j 2 is an upgrade to Log4j that provides significant improvements over its predecessor, Log4j 1.x, and provides many other modern features
such as support for Markers, lambda expressions for lazy logging, property substitution using Lookups, multiple patterns on a PatternLayout and asynchronous Loggers. Another notable Log4j 2 feature is the ability to be “garbage-free” (avoid allocating temporary objects) while logging. In addition, Log4j 2 will not lose events while
Apache Log4j 2.13.3 has been released.
- Fix NullPointerException in ThreadContextDataInjector. Fixes LOG4J2-2838