Load Config properties outside a JAR file.

ConfigReader.java

public class ConfigReader {

    public static Map<String, String> readConfig() {

        Map<String, String> config = new HashMap<>(3);

        Properties prop = new Properties();

        CodeSource codeSource = ConfigReader.class.getProtectionDomain().getCodeSource();

        try {
            File jarFile = new File(codeSource.getLocation().toURI().getPath());
            String jarDir = jarFile.getParentFile().getPath();
            System.out.println("Loading config data from :: " + jarDir + File.separator + "config.properties");
            InputStream input = new FileInputStream(jarDir + File.separator + "config.properties");

            prop.load(input);

            config.put("KEY_1", prop.getProperty("KEY_1"));
            config.put("KEY_2", prop.getProperty("KEY_2"));
        } catch (IOException | URISyntaxException e) {
            e.printStackTrace();
        }

        return config;
    }
}