## Package org.apache.log4j

The main log4j package.

See:
Description

Interface Summary
Appender: Implement this interface for your own strategies for outputting log statements.

Class Summary
AppenderSkeleton: Abstract superclass of the other appenders in the package.
AsyncAppender: The AsyncAppender lets users log events asynchronously.
BasicConfigurator: Use this class to quickly configure the package.
Category: This class has been deprecated and replaced by the `Logger` subclass.
ConsoleAppender: ConsoleAppender appends log events to `System.out` or `System.err` using a layout specified by the user.
DailyRollingFileAppender: DailyRollingFileAppender extends `FileAppender` so that the underlying file is rolled over at a user chosen frequency.
DefaultThrowableRenderer: Default implementation of ThrowableRenderer using Throwable.printStackTrace.
EnhancedPatternLayout: This class is an enhanced version of org.apache.log4j.PatternLayout which was originally developed as part of the abandoned log4j 1.3 effort and has been available in the extras companion.
EnhancedThrowableRenderer: Enhanced implementation of ThrowableRenderer.
FileAppender: FileAppender appends log events to a file.
Hierarchy: This class is specialized in retrieving loggers by name and also maintaining the logger hierarchy.
HTMLLayout: This layout outputs events in a HTML table.
Layout: Extend this abstract class to create your own log layout format.
Level: Defines the minimum set of levels recognized by the system, that is `OFF`, `FATAL`, `ERROR`, `WARN`, `INFO</code, <code>DEBUG` and `ALL`.
Logger: This is the central class in the log4j package.
LogManager: Use the `LogManager` class to retreive `Logger` instances or to operate on the current `LoggerRepository`.
LogMF: This class provides parameterized logging services using the pattern syntax of java.text.MessageFormat.
LogSF: This class provides parameterized logging services using the SLF4J pattern syntax.
LogXF: This is a base class for LogMF and LogSF parameterized logging classes.
MDC: The MDC class is similar to the `NDC` class except that it is based on a map instead of a stack.
NDC: The NDC class implements nested diagnostic contexts as defined by Neil Harrison in the article "Patterns for Logging Diagnostic Messages" part of the book "Pattern Languages of Program Design 3" edited by Martin et al.
PatternLayout: A flexible layout configurable with pattern string.
Priority: Refrain from using this class directly, use the `Level` class instead.
PropertyConfigurator: Allows the configuration of log4j from an external file.
RollingFileAppender: RollingFileAppender extends FileAppender to backup the log files when they reach a certain size.
SimpleLayout: SimpleLayout consists of the level of the log statement, followed by " - " and then the log message itself.
TTCCLayout: TTCC layout format consists of time, thread, category and nested diagnostic context information, hence the name.
WriterAppender: WriterAppender appends log events to a `Writer` or an `OutputStream` depending on the user's choice.

## Package org.apache.log4j Description

The main log4j package.

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