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.Enumeration;
23
24 /**
25 * This interface defines a method for getting the "elements" of an object, which means any objects that naturally would
26 * be considered to be contained by the object. So for a collection, you would expect this method to return all the
27 * objects in that collection; while for an ordinary object you would expect this method to return just that object.
28 * <p>
29 * An implementation of this interface will often require that its target objects all be of some particular type. For
30 * example, the MapElementsAccessor class requires that its targets all implement the Map interface.
31 *
32 * @author Luke Blanshard (blanshlu@netscape.net)
33 * @author Drew Davidson (drew@ognl.org)
34 */
35 public interface ElementsAccessor
36 {
37 /**
38 * Returns an iterator over the elements of the given target object.
39 *
40 * @param target the object to get the elements of
41 * @return an iterator over the elements of the given object
42 * @exception OgnlException if there is an error getting the given object's elements
43 */
44 Enumeration<?> getElements( Object target ) throws OgnlException;
45 }