[ 
https://issues.apache.org/jira/browse/LOG4J2-1842?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15906591#comment-15906591
 ] 

Mihhail Lapushkin commented on LOG4J2-1842:
-------------------------------------------

Hm, that's a nice discovery. The syntax is actually: 
`${sys:some.property:-defaultValue}` (note the dash). Maybe it would be enough 
for me ATM.
However, I am opened to refactor this to be part of `StrSubstitutor`.

> Expand SystemPropertiesLookup syntax
> ------------------------------------
>
>                 Key: LOG4J2-1842
>                 URL: https://issues.apache.org/jira/browse/LOG4J2-1842
>             Project: Log4j 2
>          Issue Type: Improvement
>          Components: Lookups
>            Reporter: Mihhail Lapushkin
>            Priority: Minor
>
> I've been using a modified version of {{SystemPropertiesLookup}} in my 
> project. Maybe it could be part of the library.
> The idea is to allow a series of property keys to be specified. If one of the 
> properties is present, then it is used. If none are present, then the default 
> value is used. For example:
> {code}
> <Logger name="com.myapp.dao" 
> level="${sys:myapp.log.level|myapp.log.level.dao|warn}"/>
> <Logger name="com.myapp.service" 
> level="${sys:myapp.log.level|myapp.log.level.service|warn}"/>
> <Logger name="com.myapp.controller" 
> level="${sys:myapp.log.level|myapp.log.level.controller|warn}"/>
> {code}
> This allows me to quickly rerun the app with different log levels without 
> fiddling with the configuration file or JConsole. Defaults represent 
> production settings, so that nothing extra needs to be specified to run the 
> app.
> This work nice in other places as well:
> {code}
> <PatternLayout disableAnsi="${sys:myapp.log.nocolor|true}">
> {code}
> Disables colors by default (for production build), but leaves an easy way to 
> turn them on for development.
> When no pipes are present in the expression, then the standard property 
> lookup is used, so the change is backwards-compatible.
> Can be a separate lookup if needed.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

---------------------------------------------------------------------
To unsubscribe, e-mail: log4j-dev-unsubscr...@logging.apache.org
For additional commands, e-mail: log4j-dev-h...@logging.apache.org

Reply via email to