001    /*
002     * Copyright (C) 2008 Google Inc.
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    
017    package com.google.common.collect;
018    
019    import com.google.common.annotations.GwtCompatible;
020    
021    import java.util.Iterator;
022    
023    /**
024     * An iterator that does not support {@link #remove}.
025     *
026     * @author Jared Levy
027     * @since 2 (imported from Google Collections Library)
028     */
029    @GwtCompatible
030    public abstract class UnmodifiableIterator<E> implements Iterator<E> {
031      /**
032       * Guaranteed to throw an exception and leave the underlying data unmodified.
033       *
034       * @throws UnsupportedOperationException always
035       */
036      public final void remove() {
037        throw new UnsupportedOperationException();
038      }
039    }