How to put a directory first on the classpath with Spring Boot?

Question

I am building my Spring Boot application using Maven, so I can start it with:

java -jar myjar-1.0-SNAPSHOT.jar --spring.profiles.active=prod

I want to have a directory first on the classpath that would allow me to place some files on the filesystem without having to unzip the jar to change them.

I have tried using loader.path, but it does not seem to work.

java -Dloader.path="config/*" -jar myjar-1.0-SNAPSHOT.jar --spring.profiles.active=prod

The config dir is a subdirectory of where the jar is located. I am trying to load a keystore file which is injected as a Resource in my application. There is such a file in the src/main/resources, but that only works in my IDE, not when packaged as a jar. So I want to put a file first on the classpath so that that one is found first on the classpath.

Answer 1

You can use loader.path but only if the Main-Class is PropertiesLauncher (so it depends how you built the JAR file). Maybe you need to re-build the JAR with packaging=ZIP in the Boot plugin (e.g. docs here)? Can you not set the path to the keystore as a "file:" URL?