Java -jar : access external configuration file

Question

I\'m looking to do something which I thought was not going to be difficult.

I have an application that I\'d like to package up as a jar because I\'ve got ~30 depend

Answer 1

You need to add "." to the classpath of the jar file you are building for your application.

So in the manifest, I'd expect to see

Main-Class: some.full.Name
Class-Path: . needed-lib.jar other-lib.jar 

Then, when you run your app by executing

java -jar myapp.jar

it actually uses

java -classpath .;needed-lib.jar;other-lib.jar some.full.Name

This way any file in the directory with the myapp.jar file will also be on the classpath. That classpath is relative to the location of jar containing it.

Log4j for one expects the log4j.xml configuration file to be on the classpath. If you aren't using the name log4j.xml you also have to add a system property to your start up command to tell the log4j library to look for a different name.

I'm not sure what Spring expects for configuration files. And property file loading depends on what mechanism is used to load the file. Using a FileReader or InputStream doesn't use the classpath mechanism at all. In that case you need to know where the application is expecting the file to be relative to the current working directory.