001    package org.apache.commons.ognl;
002    
003    /*
004     * Licensed to the Apache Software Foundation (ASF) under one
005     * or more contributor license agreements.  See the NOTICE file
006     * distributed with this work for additional information
007     * regarding copyright ownership.  The ASF licenses this file
008     * to you under the Apache License, Version 2.0 (the
009     * "License"); you may not use this file except in compliance
010     * with the License.  You may obtain a copy of the License at
011     *
012     *   http://www.apache.org/licenses/LICENSE-2.0
013     *
014     * Unless required by applicable law or agreed to in writing,
015     * software distributed under the License is distributed on an
016     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017     * KIND, either express or implied.  See the License for the
018     * specific language governing permissions and limitations
019     * under the License.
020     */
021    
022    import java.util.Iterator;
023    import java.util.Map;
024    
025    /**
026     * Implementation of PropertyAccessor that provides "property" reference to "next" and "hasNext".
027     * 
028     * @author Luke Blanshard (blanshlu@netscape.net)
029     * @author Drew Davidson (drew@ognl.org)
030     */
031    public class IteratorPropertyAccessor
032        extends ObjectPropertyAccessor
033        implements PropertyAccessor // This is here to make javadoc show this class as an implementor
034    {
035        @Override
036        public Object getProperty( Map<String, Object> context, Object target, Object name )
037            throws OgnlException
038        {
039            Object result;
040            Iterator<?> iterator = (Iterator<?>) target; // check performed by the invoker
041    
042            if ( name instanceof String )
043            {
044                if ( "next".equals( name ) )
045                {
046                    result = iterator.next();
047                }
048                else
049                {
050                    if ( "hasNext".equals( name ) )
051                    {
052                        result = iterator.hasNext() ? Boolean.TRUE : Boolean.FALSE;
053                    }
054                    else
055                    {
056                        result = super.getProperty( context, target, name );
057                    }
058                }
059            }
060            else
061            {
062                result = super.getProperty( context, target, name );
063            }
064            return result;
065        }
066    
067        @Override
068        public void setProperty( Map<String, Object> context, Object target, Object name, Object value )
069            throws OgnlException
070        {
071            throw new IllegalArgumentException( "can't set property " + name + " on Iterator" );
072        }
073    }