test.java

@Test
public void testJobConfigurationValidity() {
  final Reflections reflections = new Reflections(JobConfigurationBase.class.getPackage().getName());
  final Set<Class<? extends JobConfigurationBase>> configs = reflections.getSubTypesOf(JobConfigurationBase.class);
  final List<String> errorList = new ArrayList<>();

  configs.stream()
    .filter(config -> !Modifier.isAbstract(config.getModifiers()) && !config.isAnonymousClass())
    .forEach(config -> {
      try {
        final JobConfigurationBase jobConfig = config.newInstance();
        
        if (jobConfig.getRetries() < 0) {
          errorList.add(String.format("Retries must be non negative for %s", jobConfig));
        }

        if (jobConfig.getRunCommand() == null || jobConfig.getRunCommand().isEmpty()) {
          errorList.add(String.format("Command must exist for %s", jobConfig));
        }
      } catch (InstantiationException | IllegalAccessException e) {
        errorList.add(String.format("%s cannot be instantiated", config));
      }
    });
    
  assertTrue(errorList.stream().collect(Collectors.joining("\n")), errorList.isEmpty());
}