View Javadoc

1   package org.apache.commons.ognl;
2   
3   /*
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *   http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  import java.util.Iterator;
23  import java.util.Map;
24  
25  /**
26   * Implementation of PropertyAccessor that provides "property" reference to "next" and "hasNext".
27   * 
28   * @author Luke Blanshard (blanshlu@netscape.net)
29   * @author Drew Davidson (drew@ognl.org)
30   */
31  public class IteratorPropertyAccessor
32      extends ObjectPropertyAccessor
33      implements PropertyAccessor // This is here to make javadoc show this class as an implementor
34  {
35      @Override
36      public Object getProperty( Map<String, Object> context, Object target, Object name )
37          throws OgnlException
38      {
39          Object result;
40          Iterator<?> iterator = (Iterator<?>) target; // check performed by the invoker
41  
42          if ( name instanceof String )
43          {
44              if ( "next".equals( name ) )
45              {
46                  result = iterator.next();
47              }
48              else
49              {
50                  if ( "hasNext".equals( name ) )
51                  {
52                      result = iterator.hasNext() ? Boolean.TRUE : Boolean.FALSE;
53                  }
54                  else
55                  {
56                      result = super.getProperty( context, target, name );
57                  }
58              }
59          }
60          else
61          {
62              result = super.getProperty( context, target, name );
63          }
64          return result;
65      }
66  
67      @Override
68      public void setProperty( Map<String, Object> context, Object target, Object name, Object value )
69          throws OgnlException
70      {
71          throw new IllegalArgumentException( "can't set property " + name + " on Iterator" );
72      }
73  }