001/* 002 * Copyright (C) 2008 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 java.util.Iterator; 021 022/** 023 * An iterator that does not support {@link #remove}. 024 * 025 * <p>{@code UnmodifiableIterator} is used primarily in conjunction with implementations of {@link 026 * ImmutableCollection}, such as {@link ImmutableList}. You can, however, convert an existing 027 * iterator to an {@code UnmodifiableIterator} using {@link Iterators#unmodifiableIterator}. 028 * 029 * @author Jared Levy 030 * @since 2.0 031 */ 032@GwtCompatible 033public abstract class UnmodifiableIterator<E> implements Iterator<E> { 034 /** Constructor for use by subclasses. */ 035 protected UnmodifiableIterator() {} 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 public final void remove() { 046 throw new UnsupportedOperationException(); 047 } 048}