No log4j2 configuration file found. Using default configuration: logging only errors to the console

Question

$ java -Dlog4j.configuration=file:///path/to/your/log4j2.xml -jar /path/to/your/jar_file.jar

Written to the console, you get

ERROR          


        

Answer 1

In my case I am using the log4j2 Json file log4j2.json in the classpath of my gradle project and I got the same error.

The solution here was to add dependency for JSON handling to my gradle dependencies.

compile group:"com.fasterxml.jackson.core", name:"jackson-core", version:'2.8.4'
compile group:"com.fasterxml.jackson.core", name:"jackson-databind", version:'2.8.4'
compile group:"com.fasterxml.jackson.core", name:"jackson-annotations", version:'2.8.4'

See also documentation of log4j2:

The JSON support uses the Jackson Data Processor to parse the JSON files. These dependencies must be added to a project that wants to use JSON for configuration: