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.Beta;
020import com.google.common.annotations.GwtCompatible;
021
022import java.util.ListIterator;
023
024/**
025 * A list iterator that does not support {@link #remove}, {@link #add}, or
026 * {@link #set}.
027 *
028 * @since 7
029 * @author Louis Wasserman
030 */
031@Beta
032@GwtCompatible
033public abstract class UnmodifiableListIterator<E> 
034    extends UnmodifiableIterator<E> implements ListIterator<E> {
035  /** Constructor for use by subclasses. */
036  protected UnmodifiableListIterator(){}
037  
038  /**
039   * Guaranteed to throw an exception and leave the underlying data unmodified.
040   *
041   * @throws UnsupportedOperationException always
042   */
043  @Override public final void add(E e) {
044    throw new UnsupportedOperationException();
045  }
046
047  /**
048   * Guaranteed to throw an exception and leave the underlying data unmodified.
049   *
050   * @throws UnsupportedOperationException always
051   */
052  @Override public final void set(E e) {
053    throw new UnsupportedOperationException();
054  }
055}