[LOG4J2-2197] Document default property value support

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Invalid
• Affects Version/s: 2.10.0
• Component/s: Lookups
• Labels: Documentation
• Assignee: Unassigned
• Reporter: Fabrice Daugan
• Created: 17/Jan/18 07:47
• Updated: 22/Jan/18 14:23
• Resolved: 17/Jan/18 08:44

Description

As Spring and some other libraries, it would be nice to support default property value. For sample : 

${sys:property_name:default_value}

Lookup will return the actual system property value of "property_name" if defined, otherwise "default_value".

The form without default value would work as normal and return a "null" value when this property is not defined.

The way of getting the default value will be similar to "ResourceBundleLookup" and both "EnvironmentLookup" and "SystemPropertiesLookup" will benefit this feature.

Patch incoming...

Issue Links

• links to: GitHub Pull Request #142