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.util.Map;
23
24 import org.apache.velocity.runtime.log.Log;
25
26 /**
27 * GetExecutor that is smart about Maps. If it detects one, it does not
28 * use Reflection but a cast to access the getter.
29 *
30 * @author <a href="mailto:henning@apache.org">Henning P. Schmiedehausen</a>
31 * @version $Id: MapGetExecutor.java 463298 2006-10-12 16:10:32Z henning $
32 */
33 public class MapGetExecutor
34 extends AbstractExecutor
35 {
36 private final String property;
37
38 public MapGetExecutor(final Log log, final Class clazz, final String property)
39 {
40 this.log = log;
41 this.property = property;
42 discover(clazz);
43 }
44
45 protected void discover (final Class clazz)
46 {
47 Class [] interfaces = clazz.getInterfaces();
48 for (int i = 0 ; i < interfaces.length; i++)
49 {
50 if (interfaces[i].equals(Map.class))
51 {
52 try
53 {
54 if (property != null)
55 {
56 setMethod(Map.class.getMethod("get", new Class [] { Object.class }));
57 }
58 }
59 /**
60 * pass through application level runtime exceptions
61 */
62 catch( RuntimeException e )
63 {
64 throw e;
65 }
66 catch(Exception e)
67 {
68 log.error("While looking for get('" + property + "') method:", e);
69 }
70 break;
71 }
72 }
73 }
74
75 public Object execute(final Object o)
76 {
77 return ((Map) o).get(property);
78 }
79 }