Package org.apache.log4j.rule

Class ExistsRule

java.lang.Object

org.apache.log4j.rule.AbstractRule

org.apache.log4j.rule.ExistsRule

All Implemented Interfaces:

Serializable, Rule

public class ExistsRule
extends AbstractRule

A Rule class implementing a not null (and not empty string) check.

Author:

Scott Deboy (sdeboy@apache.org)

See Also:

• Serialized Form

Method Summary

Modifier and Type	Method	Description
boolean	evaluate(org.apache.log4j.spi.LoggingEvent event, Map matches)	Returns true if this implementation of the rule accepts the LoggingEvent, or false if not.
static Rule	getRule(String field)	Get an instance of ExistsRule.
static Rule	getRule(Stack stack)	Create an instance of ExistsRule using the top name on the stack.

Methods inherited from class org.apache.log4j.rule.AbstractRule

addPropertyChangeListener, firePropertyChange, firePropertyChange, removePropertyChangeListener

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

getRule

public static Rule getRule(String field)

Get an instance of ExistsRule.

Parameters:

field - field.

Returns:

instance of ExistsRule.

getRule

public static Rule getRule(Stack stack)

Create an instance of ExistsRule using the top name on the stack.

Parameters:

stack - stack

Returns:

instance of ExistsRule.

evaluate

public boolean evaluate(org.apache.log4j.spi.LoggingEvent event,
 Map matches)

Returns true if this implementation of the rule accepts the LoggingEvent, or false if not.

What True/False means can be client-specific.

Parameters:

event - LoggingEvent this instance will evaluate

matches - a Map of event field keys to Sets of matching strings (may be null) which will be updated during execution of this method to include field and string matches based on the rule evaluation results

Returns:

true if this Rule instance accepts the event, otherwise false.