A Properties file stored in a JAR can be loaded this way
import java.net.URL; import java.util.Properties; import javax.swing.JApplet; public class Main extends JApplet { public static void main(String[] a) throws Exception { Properties p = new Properties(); URL url = ClassLoader.getSystemResource("/com/java2s/config/system.props"); if (url != null) p.load(url.openStream()); } }