View Javadoc

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 PutExecutor and SetPropertyExecutor.
31   *
32   * There really should be a superclass for this and AbstractExecutor (which should
33   * be refactored to GetExecutor) because they differ only in the execute() method.
34   *
35   * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
36   * @author <a href="mailto:geirm@apache.org">Geir Magnusson Jr.</a>
37   * @author <a href="mailto:henning@apache.org">Henning P. Schmiedehausen</a>
38   * @version $Id: SetExecutor.java 463298 2006-10-12 16:10:32Z henning $
39   */
40  public abstract class SetExecutor
41  {
42      /** Class logger */
43      protected Log log = null;
44  
45      /**
46       * Method to be executed.
47       */
48      private Method method = null;
49  
50      /**
51       * Execute method against context.
52       * @param o
53       * @param value
54       * @return The result of the invocation.
55       * @throws IllegalAccessException
56       * @throws InvocationTargetException
57       */
58      public abstract Object execute(Object o, Object value)
59           throws IllegalAccessException, InvocationTargetException;
60  
61      /**
62       * Tell whether the executor is alive by looking
63       * at the value of the method.
64       * @return True if the executor is alive.
65       */
66      public boolean isAlive()
67      {
68          return (method != null);
69      }
70  
71      /**
72       * @return The method to invoke.
73       */
74      public Method getMethod()
75      {
76          return method;
77      }
78  
79      /**
80       * @param method
81       */
82      protected void setMethod(final Method method)
83      {
84          this.method = method;
85      }
86  }