import org.yaml.snakeyaml.Yaml; public class SnakeYamlVerificaation { public static void main(final String[] args) { final Person p = new Person(); p.firstName = "John"; p.familyName = "Kay"; p.nationality = "UK"; p.age = 28; final Yaml y = new Yaml(); System.out.println(y.dump(p)); } } Exception in thread "main" org.yaml.snakeyaml.error.YAMLException: No JavaBean properties found in jp.toastkid.v