001 /* 002 * JBoss DNA (http://www.jboss.org/dna) 003 * See the COPYRIGHT.txt file distributed with this work for information 004 * regarding copyright ownership. Some portions may be licensed 005 * to Red Hat, Inc. under one or more contributor license agreements. 006 * See the AUTHORS.txt file in the distribution for a full listing of 007 * individual contributors. 008 * 009 * Unless otherwise indicated, all code in JBoss DNA is licensed 010 * to you under the terms of the GNU Lesser General Public License as 011 * published by the Free Software Foundation; either version 2.1 of 012 * the License, or (at your option) any later version. 013 * 014 * JBoss DNA is distributed in the hope that it will be useful, 015 * but WITHOUT ANY WARRANTY; without even the implied warranty of 016 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 017 * Lesser General Public License for more details. 018 * 019 * You should have received a copy of the GNU Lesser General Public 020 * License along with this software; if not, write to the Free 021 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 022 * 02110-1301 USA, or see the FSF site: http://www.fsf.org. 023 */ 024 package org.jboss.dna.common.collection; 025 026 import java.util.Iterator; 027 028 /** 029 * An {@link Iterator} implementation that only allows reading elements, used as a wrapper around another iterator to make the 030 * contents appear to be immutable. 031 * 032 * @param <T> the type that is being iterated over 033 */ 034 public final class ReadOnlyIterator<T> implements Iterator<T> { 035 036 private final Iterator<T> delegate; 037 038 public ReadOnlyIterator( Iterator<T> delegate ) { 039 this.delegate = delegate; 040 assert this.delegate != null; 041 } 042 043 /** 044 * {@inheritDoc} 045 * 046 * @see java.util.Iterator#hasNext() 047 */ 048 public boolean hasNext() { 049 return delegate.hasNext(); 050 } 051 052 /** 053 * {@inheritDoc} 054 * 055 * @see java.util.Iterator#next() 056 */ 057 public T next() { 058 return delegate.next(); 059 } 060 061 /** 062 * {@inheritDoc} 063 * 064 * @see java.util.Iterator#remove() 065 */ 066 public void remove() { 067 throw new UnsupportedOperationException(); 068 } 069 070 }