How to override Java resources when you run Spring Boot fat-jar?

Question

How to override Java resources when you run Spring Boot fat-jar?

I've created a Spring Boot far-jar that contains inside as resource a log4j.xml configuration file. Now when I run the fat-jar I'm trying to override it in this way

$ java -cp conf/ -jar target/myapp.jar

and I've put in the conf/ folder a new log4j.xml. But nothing, it continues to use the resource inside the jar.

Answer 1

If your goal is only to define your own log4j.xml configuration file, this could help:

java -Dlogging.config='/path/to/log4j2.xml' -jar target/myapp.jar

(this was mentioned already in How can I change the default location of log4j2.xml in Java Spring Boot? )

If you just want to add resources by classpath addition you could refer to https://docs.spring.io/spring-boot/docs/current/reference/html/appendix-executable-jar-format.html#executable-jar-property-launcher-features where I found loader.path :

loader.path can contain directories (which are scanned recursively for jar and zip files), archive paths, a directory within an archive that is scanned for jar files (for example, dependencies.jar!/lib), or wildcard patterns (for the default JVM behavior). Archive paths can be relative to loader.home or anywhere in the file system with a jar:file: prefix.