How to use com.ning.billing.util.config.catalog

private Collection<? extends ValidationError> validate(final StandaloneCatalog catalog,
                            final ValidationErrors errors, final ValidatingConfig<StandaloneCatalog>[] configs) {
  for (final ValidatingConfig<StandaloneCatalog> config : configs) {
    config.validate(catalog, errors);
  }
  return errors;
}

public void add(final String description, final URI catalogURI,
        final Class<?> objectType, final String objectName) {
  add(new ValidationError(description, catalogURI, objectType, objectName));
}

public void log(final Logger log) {
  for (final ValidationError error : this) {
    error.log(log);
  }
}

public static <T extends ValidatingConfig<T>> void validate(final URI uri, final T c) throws ValidationException {
  c.initialize(c, uri);
  final ValidationErrors errs = c.validate(c, new ValidationErrors());
  log.info("Errors: " + errs.size() + " for " + uri);
  if (errs.size() > 0) {
    throw new ValidationException(errs);
  }
}

public static <T extends ValidatingConfig<T>> T getObjectFromStream(final URI uri, final InputStream stream, final Class<T> clazz) throws SAXException, InvalidConfigException, JAXBException, IOException, TransformerException, ValidationException {
  if (stream == null) {
    return null;
  }
  final Object o = unmarshaller(clazz).unmarshal(stream);
  if (clazz.isInstance(o)) {
    @SuppressWarnings("unchecked") final
    T castObject = (T) o;
    try {
      validate(uri, castObject);
    } catch (ValidationException e) {
      e.getErrors().log(log);
      System.err.println(e.getErrors().toString());
      throw e;
    }
    return castObject;
  } else {
    return null;
  }
}

public static <T extends ValidatingConfig<T>> T getObjectFromUri(final URI uri, final Class<T> objectType) throws Exception {
  if (uri == null) {
    return null;
  }
  log.info("Initializing an object of class " + objectType.getName() + " from xml file at: " + uri);
  return getObjectFromStream(uri, UriAccessor.accessUri(uri), objectType);
}

@Override
public void initialize(final StandaloneCatalog root, final URI uri) {
  if (prices == null) {
    prices = getZeroPrice(root);
  }
  super.initialize(root, uri);
}

public static String accessUriAsString(String uri)  throws IOException, URISyntaxException {
  return accessUriAsString(new URI(uri));
}

public static InputStream accessUri(String uri)  throws IOException, URISyntaxException {
  return accessUri(new URI(uri));
}

public String toString() {
  final StringBuilder builder = new StringBuilder();
  for (final ValidationError error : this) {
    builder.append(error.toString());
  }
  return builder.toString();
}

@Override
public void printStackTrace(final PrintStream arg0) {
  arg0.print(errors.toString());
  super.printStackTrace(arg0);
}

@Override
public ValidationErrors validate(final StandaloneCatalog catalog, final ValidationErrors errors) {
  for (final StandaloneCatalog c : versions) {
    errors.addAll(c.validate(c, errors));
  }
  //TODO MDW validation - ensure all catalog versions have a single name
  //TODO MDW validation - ensure effective dates are different (actually do we want this?)
  //TODO MDW validation - check that all products are there
  //TODO MDW validation - check that all plans are there
  //TODO MDW validation - check that all currencies are there
  //TODO MDW validation - check that all pricelists are there
  return errors;
}

@Override
public ValidationErrors validate(final StandaloneCatalog catalog, final ValidationErrors errors) {
  //Validation: TimeUnit UNLIMITED iff number == -1
  if ((unit == TimeUnit.UNLIMITED && number != -1)) {
    errors.add(new ValidationError("Duration can only have 'UNLIMITED' unit if the number is omitted.",
                    catalog.getCatalogURI(), DefaultPlanPhase.class, ""));
  }
  //TODO MDW - Validation TimeUnit UNLIMITED iff number == -1
  return errors;
}

public static <T extends ValidatingConfig<T>> T getObjectFromString(final String uri, final Class<T> objectType) throws Exception {
  if (uri == null) {
    return null;
  }
  log.info("Initializing an object of class " + objectType.getName() + " from xml file at: " + uri);
  return getObjectFromStream(new URI(uri), UriAccessor.accessUri(uri), objectType);
}

@Override
public void initialize(final StandaloneCatalog catalog, final URI sourceURI) {
  super.initialize(catalog, sourceURI);
  if (finalPhase != null) {
    finalPhase.setPlan(this);
    finalPhase.initialize(catalog, sourceURI);
  }
  if (initialPhases != null) {
    for (final DefaultPlanPhase p : initialPhases) {
      p.setPlan(this);
      p.initialize(catalog, sourceURI);
    }
  }
}

  public static String accessUriAsString(URI uri) throws IOException,  URISyntaxException {
    InputStream stream = accessUri(uri);
    return new Scanner(stream).useDelimiter("\\A").next();
  }
}

@Override
public ValidationErrors validate(final OverdueConfig root,
                 final ValidationErrors errors) {
  if (name.length() > MAX_NAME_LENGTH) {
    errors.add(new ValidationError(String.format("Name of state '%s' exceeds the maximum length of %d", name, MAX_NAME_LENGTH), root.getURI(), DefaultOverdueState.class, name));
  }
  return errors;
}

@Override
public ValidationErrors validate(StandaloneCatalog root, ValidationErrors errors) {
  if(max == null && min == null) {
    errors.add(new ValidationError("max and min cannot both be ommitted",root.getCatalogURI(), Limit.class, ""));
  } else if (max != null && min != null && max.doubleValue() < min.doubleValue()) {
    errors.add(new ValidationError("max must be greater than min",root.getCatalogURI(), Limit.class, ""));
  }
  return errors;
}

@Override
public ValidationErrors validate(final StandaloneCatalog catalog, final ValidationErrors errors) {
  if (effectiveDateForExistingSubscriptons != null &&
      catalog.getEffectiveDate().getTime() > effectiveDateForExistingSubscriptons.getTime()) {
    errors.add(new ValidationError(String.format("Price effective date %s is before catalog effective date '%s'",
                           effectiveDateForExistingSubscriptons,
                           catalog.getEffectiveDate().getTime()),
                    catalog.getCatalogURI(), DefaultInternationalPrice.class, ""));
  }
  return errors;
}

@Override
public ValidationErrors validate(final StandaloneCatalog catalog, final ValidationErrors errors) {
  super.validate(catalog, errors);
  if (!getName().equals(PriceListSet.DEFAULT_PRICELIST_NAME)) {
    errors.add(new ValidationError("The name of the default pricelist must be 'DEFAULT'",
                    catalog.getCatalogURI(), DefaultPriceList.class, getName()));
  }
  return errors;
}