public interface AppConfig { @Config("database.url") String getDatabaseUrl(); @Config("database.username") String getDatabaseUsername(); @Config("database.password") String getDatabasePassword(); @Config("email.server") String getEmailServer(); @Config("email.username") String getEmailUsername(); @Config("email.password") String getEmailPassword(); } properties database.url=jdbc:mysql://localhost:3306/mydb database.username=root database.password=123456 email.server=smtp.gmail.com email.username=example@gmail.com email.password=secret ConfigMagicFactory factory = new ConfigMagicFactory(); AppConfig config = factory.load(AppConfig.class, "app-config.properties"); public class DatabaseConnection { public void connect(String url, String username, String password) { } } DatabaseConnection connection = new DatabaseConnection(); connection.connect(config.getDatabaseUrl(), config.getDatabaseUsername(), config.getDatabasePassword());