[LOG4J2-419] Support default value for missing key in look ups with fallbacking to looking in the properties map

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.0-rc2
• Assignee: Unassigned
• Reporter: Woonsan Ko
• Created: 10/Oct/13 14:08
• Updated: 10/Jun/14 15:57
• Resolved: 10/Jun/14 03:14

Description

It is more useful and flexible to allow default value in the variable expression itself.
For example,

${var1:-defvalue1},
${ctx:request_id:-defvalue2}, etc.

This generic feature has been included in StrSubstitutor of commons-lang3 as well with the following issue:

• https://issues.apache.org/jira/browse/LANG-893

The benefit from the feature with LANG-893 is we can use it more widely whenever used in look ups.

Issue Links

• relates to: LOG4J2-418 Support default value for missing key in map-based pattern