/**
* Constructs an instance of the BreadthFirstIterator class wrapping the Iterator of Iterators to
* collectively traverse the Iterators in order, left to right, top to bottom.
*
* @param iterators the Iterator of Iterators to encapsulate in a breadth-first traversal.
* @throws java.lang.NullPointerException if the Iterator of Iterators reference is null.
* @see java.util.Iterator
*/
public BreadthFirstIterator(final Iterator<Iterator<T>> iterators) {
Assert.notNull(iterators, "The Iterator of Iterators must not be null!");
for (Iterator<T> iterator : CollectionUtils.iterable(iterators)) {
if (iterator != null) {
this.iterators.add(iterator);
}
}
}
/**
* Constructs an instance of the {@link RegexFileFilter} class initialized with the given regular
* expression (regex), expressed as a {@link Pattern}.
*
* @param regularExpression regular expression (regex) used to match and filter {@link File}s.
* @throws IllegalArgumentException if the regular expression {@link Pattern} is null.
* @see java.util.regex.Pattern
*/
public RegexFileFilter(Pattern regularExpression) {
Assert.notNull(regularExpression, "The Regular Expression (Pattern) cannot be null");
this.regularExpression = regularExpression;
}