Re: Configure composite filter for specific logger in Log4j2 via properties file

Hello Stamatis,

I posted a working solution on SO:

logger.t1.filter.M.type = Filters
logger.t1.filter.M.f1.type = RegexFilter
logger.t1.filter.M.f1.regex = .*SQL.*
logger.t1.filter.M.f1.onMatch = NEUTRAL
logger.t1.filter.M.f1.onMismatch = DENY
logger.t1.filter.M.f2.type = RegexFilter
logger.t1.filter.M.f2.regex = .*JPQL.*
logger.t1.filter.M.f2.onMatch = NEUTRAL
logger.t1.filter.M.f2.onMismatch = DENY

The problem is caused by two facts:
1. The `LoggerConfig` only accepts a single filter, so you have to
wrap them in a "Filters" element,
2. A `Properties` class is a `Hashtable`, so the order of the keys is random.

I believe both of them to be bugs of `PropertiesConfigurationBuilder`:
1. I interpret the "filter" prefix in the properties configuration as
an implicit "Filters" component. `addFiltersToComponent` should wrap
the filters in a "Filters" component if more than one is defined.
2. `PropertiesUtil#partitionOnCommonPrefixes` should probably return a
`TreeMap` instead of a `HashMap` to impose a deterministic order on
the filters (and other components that use this function).

You should open a JIRA ticket for this problem and since you
apparently have a PR in progress, submit your test case and a solution
as PR.

Best wishes,
Piotr

On Sat, 2 Apr 2022 at 18:44, Stamatis Zampetakis <[email protected]> wrote:
>
> Hi all,
>
> After many unsuccessful attempts to configure a composite filter for a
> specified logger [1] using the property syntax, I posted the following
> question on stackoverflow [2].
>
> In [1], I tried to create a unit test simulating what I would like to
> achieve but didn't manage to make it work yet. I searched in the code to
> find examples of how this can be done but couldn't find any.
>
> Any feedback would be much appreciated!
>
> Best,
> Stamatis
>
> [1]
> https://github.com/zabetak/logging-log4j2/commit/a9944885100db42f7e3ba1b3ff81d59b743d0ab7
> [2]
> https://stackoverflow.com/questions/71719354/configure-composite-filter-for-specific-logger-in-log4j2-via-properties-file