Apache log4cxx  Version 0.10.0
ExpressionFilter Class Reference

A filter supporting complex expressions - supports both infix and postfix expressions (infix expressions must first be converted to postfix prior to processing). More...

Inheritance diagram for ExpressionFilter:
Filter OptionHandler ObjectImpl Object Object

List of all members.

Public Member Functions

 ExpressionFilter ()
void activateOptions (log4cxx::helpers::Pool &p)
 Usually filters options become active when set.
void setExpression (const LogString &expression)
LogString getExpression () const
void setConvertInFixToPostFix (bool convertInFixToPostFix)
bool getConvertInFixToPostFix () const
void setAcceptOnMatch (bool acceptOnMatch)
bool getAcceptOnMatch () const
FilterDecision decide (const spi::LoggingEventPtr &event) const
 Returns log4cxx::spi::Filter#NEUTRAL is there is no string match.

Detailed Description

A filter supporting complex expressions - supports both infix and postfix expressions (infix expressions must first be converted to postfix prior to processing).

See org.apache.log4j.chainsaw.LoggingEventFieldResolver.java for the correct names for logging event fields used when building expressions.

See org.apache.log4j.chainsaw.rule package for a list of available rules which can be applied using the expression syntax.

See org.apache.log4j.chainsaw.RuleFactory for the symbols used to activate the corresponding rules.

NOTE: Grouping using parentheses is supported - all tokens must be separated by spaces, and operands which contain spaces are not yet supported.

Example:

In order to build a filter that displays all messages with infomsg-45 or infomsg-44 in the message, as well as all messages with a level of WARN or higher, build an expression using the LikeRule (supports ORO-based regular expressions) and the InequalityRule. ( MSG LIKE infomsg-4[4,5] ) && ( LEVEL >= WARN )

Three options are required: Expression - the expression to match ConvertInFixToPostFix - convert from infix to posfix (default true) AcceptOnMatch - true or false (default true)

Meaning of AcceptToMatch: If there is a match between the value of the Expression option and the log4cxx::spi::LoggingEvent and AcceptOnMatch is true, the decide method returns log4cxx::spi::Filter#ACCEPT.

If there is a match between the value of the Expression option and the log4cxx::spi::LoggingEvent and AcceptOnMatch is false, log4cxx::spi::Filter#DENY is returned.

If there is no match, log4cxx::spi::Filter#NEUTRAL is returned.


Constructor & Destructor Documentation


Member Function Documentation

void activateOptions ( log4cxx::helpers::Pool p) [virtual]

Usually filters options become active when set.

We provide a

default do-nothing implementation for convenience.

Reimplemented from Filter.

FilterDecision decide ( const spi::LoggingEventPtr event) const [virtual]

Returns log4cxx::spi::Filter#NEUTRAL is there is no string match.

Implements Filter.

bool getAcceptOnMatch ( ) const
bool getConvertInFixToPostFix ( ) const
void setAcceptOnMatch ( bool  acceptOnMatch)
void setConvertInFixToPostFix ( bool  convertInFixToPostFix)
void setExpression ( const LogString expression)

The documentation for this class was generated from the following file:
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