Types of Log Appenders in log4j

Types of log appender

An appender specifies where your log messages are written to. There is a wide choice of appenders available. All appenders are direct or indirect subclasses of the AppenderSkeleton. Therefore we can find all options on the following API page:

http://logging.apache.org/log4j/docs/api/org/apache/log4j/AppenderSkeleton.html

The console and the file appender are a subclass of WriterAppender.

Later on, we are going to choose examples for the following appenders.

ConsoleAppender	Logs to console
FileAppender	Logs to a file
SMTPAppender	Logs by email
RollingFileAppender	Logs to a file, starts a new file once the max size is reached. (An alternative is the DailyRollingFileAppender which creates on file per day)

But there are as well:

AsyncAppender, JDBCAppender, JMSAppender, LF5Appender, NTEventLogAppender, NullAppender, NullAppender, SMTPAppender, SocketAppender, SocketHubAppender, SyslogAppender, TelnetAppender, DailyRollingFileAppender, RollingFileAppender.

Custom appenders can be created as well. The log4j download comes with a whole bunch of samples in the examples directory.

For more information on log4j, visit the source below.

Source : http://www.laliluna.de/log4j-tutorial.html