1 /*
2 * Copyright (C) 2008 The Guava Authors
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package com.google.common.collect;
18
19 import com.google.common.annotations.GwtCompatible;
20 import com.google.errorprone.annotations.DoNotCall;
21 import java.util.Iterator;
22
23 /**
24 * An iterator that does not support {@link #remove}.
25 *
26 * <p>{@code UnmodifiableIterator} is used primarily in conjunction with implementations of {@link
27 * ImmutableCollection}, such as {@link ImmutableList}. You can, however, convert an existing
28 * iterator to an {@code UnmodifiableIterator} using {@link Iterators#unmodifiableIterator}.
29 *
30 * @author Jared Levy
31 * @since 2.0
32 */
33 @GwtCompatible
34 public abstract class UnmodifiableIterator<E> implements Iterator<E> {
35 /** Constructor for use by subclasses. */
36 protected UnmodifiableIterator() {}
37
38 /**
39 * Guaranteed to throw an exception and leave the underlying data unmodified.
40 *
41 * @throws UnsupportedOperationException always
42 * @deprecated Unsupported operation.
43 */
44 @Deprecated
45 @Override
46 @DoNotCall("Always throws UnsupportedOperationException")
47 public final void remove() {
48 throw new UnsupportedOperationException();
49 }
50 }