An appender is a logging component that stores messages in a configured destination. A logger selects messages and sends them to one or more appenders; a formatter shapes them first. section 4.2.2
Configure an appender by deciding:
- Which destination receives messages, such as the system terminal, a file, or a database. section 4.2.2
Console appender in Log4j
A Console appender named Console targets SYSTEM_OUT and uses PatternLayout. A Root logger at info level references it, so informational messages appear in the terminal while debug messages remain hidden. Changing the Root level to debug exposes per-character diagnostic messages from StringDigitExtractor.
