1package eu.siacs.conversations.crypto.sasl;
 2
 3import java.util.ArrayList;
 4import java.util.Arrays;
 5import java.util.Iterator;
 6import java.util.List;
 7import java.util.NoSuchElementException;
 8
 9/**
10 * A tokenizer for GS2 header strings
11 */
12public final class Tokenizer implements Iterator<String>, Iterable<String> {
13	private final List<String> parts;
14	private int index;
15
16	public Tokenizer(final byte[] challenge) {
17		final String challengeString = new String(challenge);
18		parts = new ArrayList<>(Arrays.asList(challengeString.split(",")));
19		index = 0;
20	}
21
22	/**
23	 * Returns true if there is at least one more element, false otherwise.
24	 *
25	 * @see #next
26	 */
27	@Override
28	public boolean hasNext() {
29		return parts.size() != index + 1;
30	}
31
32	/**
33	 * Returns the next object and advances the iterator.
34	 *
35	 * @return the next object.
36	 * @throws java.util.NoSuchElementException if there are no more elements.
37	 * @see #hasNext
38	 */
39	@Override
40	public String next() {
41		if (hasNext()) {
42			return parts.get(index++);
43		} else {
44			throw new NoSuchElementException("No such element. Size is: " + parts.size());
45		}
46	}
47
48	/**
49	 * Removes the last object returned by {@code next} from the collection.
50	 * This method can only be called once between each call to {@code next}.
51	 *
52	 * @throws UnsupportedOperationException if removing is not supported by the collection being
53	 *                                       iterated.
54	 * @throws IllegalStateException         if {@code next} has not been called, or {@code remove} has
55	 *                                       already been called after the last call to {@code next}.
56	 */
57	@Override
58	public void remove() {
59		if(index <= 0) {
60			throw new IllegalStateException("You can't delete an element before first next() method call");
61		}
62		parts.remove(--index);
63	}
64
65	/**
66	 * Returns an {@link java.util.Iterator} for the elements in this object.
67	 *
68	 * @return An {@code Iterator} instance.
69	 */
70	@Override
71	public Iterator<String> iterator() {
72		return parts.iterator();
73	}
74}