Method unmodifiableIterator

output/java_guava/1.4.19/Iterators.java:163–181

Returns an unmodifiable view of iterator.

(final Iterator<? extends T> iterator)

  public static <T> UnmodifiableIterator<T> unmodifiableIterator(final Iterator<? extends T> iterator) {
    checkNotNull(iterator);
    if (iterator instanceof UnmodifiableIterator) {
      @SuppressWarnings("unchecked") // Since it's unmodifiable, the covariant cast is safe
      UnmodifiableIterator<T> result = (UnmodifiableIterator<T>) iterator;
      return result;
    }
    return new UnmodifiableIterator<T>() {
      @Override
      public boolean hasNext() {
        return iterator.hasNext();
      }

      @Override
      public T next() {
        return iterator.next();
      }
    };
  }

  /**
   * Simply returns its argument.