Inherited by AndFilter, DenyAllFilter, ExpressionFilter, LevelMatchFilter, LevelRangeFilter, LocationInfoFilter, MapFilter, PropertyFilter, and StringMatchFilter.
Note that Logger and AppenderSkeleton, the parent class of all standard appenders, have built-in filtering rules. It is suggested that you first use and understand the built-in rules before rushing to write your own custom filters.
This abstract class assumes and also imposes that filters be organized in a linear chain. The decide(LoggingEvent) method of each filter is called sequentially, in the order of their addition to the chain.
The decide(LoggingEvent) method must return one of the integer constants DENY, NEUTRAL or ACCEPT.
If the value DENY is returned, then the log event is dropped immediately without consulting with the remaining filters.
If the value NEUTRAL is returned, then the next filter in the chain is consulted. If there are no more filters in the chain, then the log event is logged. Thus, in the presence of no filters, the default behaviour is to log all logging events.
If the value ACCEPT is returned, then the log event is logged without consulting the remaining filters.
The philosophy of log4cxx filters is largely inspired from the Linux ipchains.
Note that filtering is only supported by the DOMConfigurator.
Public Types | |
enum | FilterDecision { DENY = -1, NEUTRAL = 0, ACCEPT = 1 } |
Public Member Functions | |
Filter () | |
void | addRef () const |
void | releaseRef () const |
log4cxx::spi::FilterPtr | getNext () const |
void | setNext (const log4cxx::spi::FilterPtr &newNext) |
void | activateOptions (log4cxx::helpers::Pool &p) |
Usually filters options become active when set. | |
void | setOption (const LogString &option, const LogString &value) |
Set option to value . | |
virtual FilterDecision | decide (const LoggingEventPtr &event) const =0 |
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Usually filters options become active when set. We provide a default do-nothing implementation for convenience. Implements OptionHandler. Reimplemented in ExpressionFilter, and LocationInfoFilter. |
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Reimplemented from ObjectImpl. |
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If the decision is
Implemented in AndFilter, DenyAllFilter, ExpressionFilter, LevelMatchFilter, LevelRangeFilter, LocationInfoFilter, MapFilter, PropertyFilter, and StringMatchFilter. |
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Reimplemented from ObjectImpl. |
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Set The handling of each option depends on the OptionHandler instance. Some options may become active immediately whereas other may be activated only when activateOptions is called. Implements OptionHandler. Reimplemented in LevelMatchFilter, LevelRangeFilter, and StringMatchFilter. |