public static void loadConfig() {
        Properties prop = new Properties();
        InputStream input = null;

        try {
            input = new FileInputStream("config.txt");
            prop.load(input);
            
            String s = prop.getProperty("PROPERTY_STRING_1");
        } catch (IOException ex) {
            ex.printStackTrace();
        } finally {
            if (input != null) {
                try {
                    input.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

I decided to use JSON configs, which is faster&simpler.

Config file structure:
PROPERTY_STRING_1=str

PROPERTY_STRING_2=str2

Simple config loading

Java