예제 #1
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 /**
  * Validates that the given collection of elements is unique.
  *
  * @param elements The elements to validate for being unique.
  * @param <T> The actual type.
  * @return The given value.
  */
 public static <T extends Collection<?>> T unique(T elements) {
   Set<Object> found = new HashSet<Object>(elements.size());
   for (Object element : elements) {
     if (!found.add(element)) {
       throw new IllegalArgumentException("Duplicate element: " + element);
     }
   }
   return elements;
 }
예제 #2
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 /**
  * Validates that a collection of generic type descriptions does not contain duplicate type
  * erasure.
  *
  * @param typeDescriptions The type descriptions to validate for being unique.
  * @param <T> The actual type of the argument.
  * @return The input value.
  */
 public static <T extends Collection<? extends GenericTypeDescription>> T uniqueRaw(
     T typeDescriptions) {
   Map<TypeDescription, GenericTypeDescription> types =
       new HashMap<TypeDescription, GenericTypeDescription>(typeDescriptions.size());
   for (GenericTypeDescription typeDescription : typeDescriptions) {
     GenericTypeDescription conflictingType =
         types.put(typeDescription.asErasure(), typeDescription);
     if (conflictingType != null) {
       throw new IllegalArgumentException(
           "Duplicate types: " + typeDescription + " and " + conflictingType);
     }
   }
   return typeDescriptions;
 }
 public static <T extends Collection<?>> boolean isVoid(T collection) {
   return collection == null || collection.size() == 0;
 }
예제 #4
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 /**
  * Validates that a collection is empty.
  *
  * @param collection The collection to be validated.
  * @param exceptionMessage The message of the exception that is thrown if the collection does
  *     contain an element.
  * @param <T> The type of the collection.
  * @return The same collection that was validated.
  */
 public static <T extends Collection<?>> T isEmpty(T collection, String exceptionMessage) {
   if (collection.size() > 0) {
     throw new IllegalArgumentException(exceptionMessage);
   }
   return collection;
 }
예제 #5
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 @Override
 public boolean isEmpty(T value) {
   return (value == null) || (value.size() == 0);
 }