Java EE 8 High Performance

Log4j

Logj4 (1.x) uses the org.apache.log4j base package. Here are the logging concepts we talked about adapted to log4j1 semantic:

Concept	Name
Logger	Logger
Logger Factory	Logger
Handler	Appender
Filter	Filter
Formatter	Layout
Level	Level

Most of the concepts are the same as in JUL, but with a few different names.

In terms of usage, it is the same as in JUL, except it uses another package:

final Logger logger = Logger.getLogger("name.of.the.logger");logger.info("message");

What is a bit different is the configuration. It uses a log4j.properties or log4j.xml in the classpath (by default) which looks like this:

log4j.rootLogger=DEBUG, stdoutlog4j.appender.stdout=org.apache.log4j.ConsoleAppenderlog4j.appender.stdout.layout=org.apache.log4j.PatternLayout ...