Are wildcards allowed in the Log4j (via Spring Boot Logging) logging.level property?

Question

While I was installing a Java application that uses Log4j (via Spring Boot Logging), I was told that I could configure the logging level for all packages used in the application by including the following line in the application.properties file:

logging.level.*=ERROR

Where ERROR could be whatever logging level I wanted to use.

However, as I changed the level from one value to another, no matter what value I used, I found that log messages down to DEBUG would appear in the log.

Eventually, I found that using specific package names I could control the minimum level to be logged. That is, logging.level.org.orgname.appname=ERROR would do what I wanted.

Are the log level properties meant to to support wildcards like "*"?

Answer 1

Since my question seems unpopular, but I've found an answer anyway, I'll post it for completeness.

Neither Log4j nor Spring Boot Logging support wildcards such as logging.level.* . There is some documentation that uses that exact phrase, but they mean for the reader to substitute a package name for the asterisk. My colleagues didn't understand that and used it verbatim in documentation for their application.

The equivalent in Spring Boot Logging is logging.level.root . The equivalent in Log4j configuration files is log4j.rootLogger , although that requires one or more additional arguments giving the names of log appender objects.