org.apache.logging.log4j.core.lookup

Class Interpolator

java.lang.Object

org.apache.logging.log4j.core.lookup.AbstractLookup

org.apache.logging.log4j.core.lookup.AbstractConfigurationAwareLookup

org.apache.logging.log4j.core.lookup.Interpolator

All Implemented Interfaces:

ConfigurationAware, LoggerContextAware, StrLookup

public class Interpolator
extends AbstractConfigurationAwareLookup
implements LoggerContextAware

Proxies all the other StrLookups.

Field Summary

Fields

Modifier and Type	Field and Description
protected WeakReference<LoggerContext>	loggerContext
static char	PREFIX_SEPARATOR Constant for the prefix separator.

Fields inherited from class org.apache.logging.log4j.core.lookup.AbstractConfigurationAwareLookup

configuration

Fields inherited from interface org.apache.logging.log4j.core.lookup.StrLookup

CATEGORY

Constructor Summary

Constructors

Constructor and Description
Interpolator() Create the default Interpolator.
Interpolator(Map<String,String> properties) Creates the default Interpolator with the provided properties.
Interpolator(StrLookup defaultLookup)
Interpolator(StrLookup defaultLookup, List<String> pluginPackages) Constructs an Interpolator using a given StrLookup and a list of packages to find Lookup plugins in.

Method Summary

Modifier and Type	Method and Description
LookupResult	evaluate(LogEvent event, String var) Resolves the specified variable.
StrLookup	getDefaultLookup()
Map<String,StrLookup>	getStrLookupMap()
String	lookup(LogEvent event, String var) Resolves the specified variable.
void	setLoggerContext(LoggerContext loggerContext) Injects the current LoggerContext into this object.
String	toString()

Methods inherited from class org.apache.logging.log4j.core.lookup.AbstractConfigurationAwareLookup

setConfiguration

Methods inherited from class org.apache.logging.log4j.core.lookup.AbstractLookup

evaluate, lookup

Methods inherited from class java.lang.Object

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

Field Detail

PREFIX_SEPARATOR

public static final char PREFIX_SEPARATOR

Constant for the prefix separator.

See Also:

Constant Field Values

loggerContext

protected WeakReference<LoggerContext> loggerContext

Constructor Detail

Interpolator

public Interpolator(StrLookup defaultLookup)

Interpolator

public Interpolator(StrLookup defaultLookup,
                    List<String> pluginPackages)

Constructs an Interpolator using a given StrLookup and a list of packages to find Lookup plugins in.

Parameters:

defaultLookup - the default StrLookup to use as a fallback

pluginPackages - a list of packages to scan for Lookup plugins

Since:

2.1

Interpolator

public Interpolator()

Create the default Interpolator.

Interpolator

public Interpolator(Map<String,String> properties)

Creates the default Interpolator with the provided properties.

Method Detail

getDefaultLookup

public StrLookup getDefaultLookup()

getStrLookupMap

public Map<String,StrLookup> getStrLookupMap()

lookup

public String lookup(LogEvent event,
                     String var)

Resolves the specified variable. This implementation will try to extract a variable prefix from the given variable name (the first colon (':') is used as prefix separator). It then passes the name of the variable with the prefix stripped to the lookup object registered for this prefix. If no prefix can be found or if the associated lookup object cannot resolve this variable, the default lookup object will be used.

Specified by:

lookup in interface StrLookup

Parameters:

event - The current LogEvent or null.

var - the name of the variable whose value is to be looked up

Returns:

the value of this variable or null if it cannot be resolved

evaluate

public LookupResult evaluate(LogEvent event,
                             String var)

Resolves the specified variable. This implementation will try to extract a variable prefix from the given variable name (the first colon (':') is used as prefix separator). It then passes the name of the variable with the prefix stripped to the lookup object registered for this prefix. If no prefix can be found or if the associated lookup object cannot resolve this variable, the default lookup object will be used.

Specified by:

evaluate in interface StrLookup

Parameters:

event - The current LogEvent or null.

var - the name of the variable whose value is to be looked up

Returns:

the value of this variable or null if it cannot be resolved

setLoggerContext

public void setLoggerContext(LoggerContext loggerContext)

Description copied from interface: LoggerContextAware

Injects the current LoggerContext into this object.

Specified by:

setLoggerContext in interface LoggerContextAware

Parameters:

loggerContext - the current LoggerContext

toString

public String toString()

Overrides:

toString in class Object