This implementation iterates over the specified collection, + * and adds each element returned by the iterator to this + * collection, in turn. A runtime exception encountered while + * trying to add an element (including, in particular, a + * null element) may result in only some of the elements + * having been successfully added when the associated exception is + * thrown. + * + * @param c collection whose elements are to be added to this collection. + * @return true if this collection changed as a result of the + * call. + * @throws NullPointerException if the specified collection, or + * any of its elements are null. + * @throws IllegalArgumentException if c is this queue. + * + * @see #add(Object) + */ + public boolean addAll(Collection extends E> c) { + if (c == null) + throw new NullPointerException(); + if (c == this) + throw new IllegalArgumentException(); + boolean modified = false; + Iterator extends E> e = c.iterator(); + while (e.hasNext()) { + if (add(e.next())) + modified = true; + } + return modified; + } + }