01: //--------------------------------------------------------------------------
02: // Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
03: // All rights reserved.
04: //
05: // Redistribution and use in source and binary forms, with or without
06: // modification, are permitted provided that the following conditions are
07: // met:
08: //
09: // Redistributions of source code must retain the above copyright notice,
10: // this list of conditions and the following disclaimer.
11: // Redistributions in binary form must reproduce the above copyright
12: // notice, this list of conditions and the following disclaimer in the
13: // documentation and/or other materials provided with the distribution.
14: // Neither the name of the Drew Davidson nor the names of its contributors
15: // may be used to endorse or promote products derived from this software
16: // without specific prior written permission.
17: //
18: // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19: // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20: // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21: // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22: // COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23: // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24: // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
25: // OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26: // AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27: // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
28: // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
29: // DAMAGE.
30: //--------------------------------------------------------------------------
31: package ognl;
32:
33: import java.util.Enumeration;
34:
35: /**
36: * This interface defines a method for getting the "elements" of an object, which means
37: * any objects that naturally would be considered to be contained by the object. So for a
38: * collection, you would expect this method to return all the objects in that collection;
39: * while for an ordinary object you would expect this method to return just that object.
40: *
41: * <p> An implementation of this interface will often require that its target objects all
42: * be of some particular type. For example, the MapElementsAccessor class requires that
43: * its targets all implement the Map interface.
44: * @author Luke Blanshard (blanshlu@netscape.net)
45: * @author Drew Davidson (drew@ognl.org)
46: */
47: public interface ElementsAccessor {
48: /**
49: * Returns an iterator over the elements of the given target object.
50: * @param target the object to get the elements of
51: * @return an iterator over the elements of the given object
52: * @exception OgnlException if there is an error getting the given object's elements
53: */
54: public Enumeration getElements(Object target) throws OgnlException;
55: }
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