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;
020import com.google.errorprone.annotations.DoNotCall;
021import java.util.ListIterator;
022import org.checkerframework.checker.nullness.qual.Nullable;
023
024/**
025 * A list iterator that does not support {@link #remove}, {@link #add}, or {@link #set}.
026 *
027 * @since 7.0
028 * @author Louis Wasserman
029 */
030@GwtCompatible
031@ElementTypesAreNonnullByDefault
032public abstract class UnmodifiableListIterator<E extends @Nullable Object>
033    extends UnmodifiableIterator<E> implements ListIterator<E> {
034  /** Constructor for use by subclasses. */
035  protected UnmodifiableListIterator() {}
036
037  /**
038   * Guaranteed to throw an exception and leave the underlying data unmodified.
039   *
040   * @throws UnsupportedOperationException always
041   * @deprecated Unsupported operation.
042   */
043  @Deprecated
044  @Override
045  @DoNotCall("Always throws UnsupportedOperationException")
046  public final void add(@ParametricNullness E e) {
047    throw new UnsupportedOperationException();
048  }
049
050  /**
051   * Guaranteed to throw an exception and leave the underlying data unmodified.
052   *
053   * @throws UnsupportedOperationException always
054   * @deprecated Unsupported operation.
055   */
056  @Deprecated
057  @Override
058  @DoNotCall("Always throws UnsupportedOperationException")
059  public final void set(@ParametricNullness E e) {
060    throw new UnsupportedOperationException();
061  }
062}