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1   package org.apache.velocity.runtime.parser.node;
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.lang.reflect.InvocationTargetException;
23  import java.lang.reflect.Method;
24  
25  import org.apache.velocity.runtime.log.Log;
26  
27  /**
28   * Abstract class that is used to execute an arbitrary
29   * method that is in introspected. This is the superclass
30   * for the GetExecutor and PropertyExecutor.
31   *
32   * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
33   * @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
34   * @version $Id: AbstractExecutor.java 463298 2006-10-12 16:10:32Z henning $
35   */
36  public abstract class AbstractExecutor
37  {
38      /** */
39      protected Log log = null;
40  
41      /**
42       * Method to be executed.
43       */
44      private Method method = null;
45  
46      /**
47       * Execute method against context.
48       * @param o
49       * @return The resulting object.
50       * @throws IllegalAccessException
51       * @throws InvocationTargetException
52       */
53       public abstract Object execute(Object o)
54           throws IllegalAccessException, InvocationTargetException;
55  
56      /**
57       * Tell whether the executor is alive by looking
58       * at the value of the method.
59       *
60       * @return True if executor is alive.
61       */
62      public boolean isAlive()
63      {
64          return (method != null);
65      }
66  
67      /**
68       * @return The current method.
69       */
70      public Method getMethod()
71      {
72          return method;
73      }
74  
75      /**
76       * @param method
77       */
78      protected void setMethod(final Method method)
79      {
80          this.method = method;
81      }
82  }