You can do this:

• Add the default configuration as an embedded resource file to the library jar
• Then the user can override the file adding a resource with the same path to the classpath

As file format you can use the Java Properties File.

And you can load it in this way

Properties props = new Properties(); props.load(ClassLoader.getResourceAsStream("name-of-your-prop-file.properties")); 

You can do this:

• Add the default configuration as an embedded resource file to the library jar
• Then the user can override the file adding a resource with the same path to the classpath

As file format you can use the Java Properties File.

And you can load it in this way

Properties props = new Properties(); props.load(YourClass.class.getResourceAsStream("name-of-your-prop-file.properties")); 

You can do this:

• Add the default configuration as an embedded resource file to the library jar
• Then the user can override the file adding a resource with the same path to the classpath

You can do this:

• Add the default configuration as an embedded resource file to the library jar
• Then the user can override the file adding a resource with the same path to the classpath

As file format you can use the Java Properties File.

And you can load it in this way

Properties props = new Properties(); props.load(ClassLoader.getResourceAsStream("name-of-your-prop-file.properties"));