001/*
002 * Copyright (C) 2010 The Guava Authors
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package com.google.common.collect;
018
019import com.google.common.annotations.GwtCompatible;
020
021import java.util.ListIterator;
022
023/**
024 * A list iterator that does not support {@link #remove}, {@link #add}, or
025 * {@link #set}.
026 *
027 * @since 7.0
028 * @author Louis Wasserman
029 */
030@GwtCompatible
031public abstract class UnmodifiableListIterator<E>
032    extends UnmodifiableIterator<E> implements ListIterator<E> {
033  /** Constructor for use by subclasses. */
034  protected UnmodifiableListIterator() {}
035
036  /**
037   * Guaranteed to throw an exception and leave the underlying data unmodified.
038   *
039   * @throws UnsupportedOperationException always
040   */
041  @Override public final void add(E e) {
042    throw new UnsupportedOperationException();
043  }
044
045  /**
046   * Guaranteed to throw an exception and leave the underlying data unmodified.
047   *
048   * @throws UnsupportedOperationException always
049   */
050  @Override public final void set(E e) {
051    throw new UnsupportedOperationException();
052  }
053}