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1   /*
2    * Copyright 2002,2004 The Apache Software Foundation.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  
17  package org.apache.commons.jexl.util.introspection;
18  
19  /***
20   * Interface defining a 'getter'. For uses when looking for resolution of
21   * property references
22   * 
23   * $foo.bar
24   * 
25   * @since 1.0
26   * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
27   * @version $Id: VelPropertyGet.java 398514 2006-05-01 03:44:34Z dion $
28   */
29  public interface VelPropertyGet {
30      /***
31       * invocation method - called when the 'get action' should be performed and
32       * a value returned.
33       * @param o the object to get the property from.
34       * @return the property value.
35       * @throws Exception on any error.
36       */
37      Object invoke(Object o) throws Exception;
38  
39      /***
40       * specifies if this VelPropertyGet is cacheable and able to be reused for
41       * this class of object it was returned for.
42       * 
43       * @return true if can be reused for this class, false if not
44       */
45      boolean isCacheable();
46  
47      /***
48       * returns the method name used to return this 'property'.
49       * @return the method name.
50       */
51      String getMethodName();
52  }