2009/05/20 - Apache Shale has been retired.

For more information, please explore the Attic.


1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to you under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.shale.tiger.managed.rules;
19  
20  import org.apache.commons.digester.Rule;
21  import org.apache.shale.tiger.managed.config.MapEntriesConfig;
22  import org.apache.shale.tiger.managed.config.MapEntryConfig;
23  import org.xml.sax.Attributes;
24  
25  /***
26   * <p>Digester rule for processing a <code>&lt;map-entry&gt;</code>
27   * element.</p>
28   */
29  public class MapEntryRule extends Rule {
30  
31      /*** Creates a new instance of MapEntryRule. */
32      public MapEntryRule() {
33      }
34  
35      /*** <p>Fully qualified class name of our configuration element bean.</p> */
36      private static final String CLASS_NAME =
37              "org.apache.shale.tiger.managed.config.MapEntryConfig";
38  
39      /***
40       * <p>Create a new {@link MapEntryConfig} and push it on to the
41       * Digester stack.</p>
42       *
43       * @param namespace Namespace URI of the matching element
44       * @param name Local name of the matching element
45       * @param attributes Attribute list of the matching element
46       *
47       * @exception Exception if a parsing error occurs
48       */
49      public void begin(String namespace, String name,
50                        Attributes attributes) throws Exception {
51  
52          Class clazz = digester.getClassLoader().loadClass(CLASS_NAME);
53          digester.push(clazz.newInstance());
54  
55      }
56  
57  
58      /***
59       * <p>No body processing for this element.</p>
60       *
61       * @param namespace Namespace URI of the matching element
62       * @param name Local name of the matching element
63       *
64       * @throws Exception if a parsing error occurs
65       */
66      public void body(String namespace, String name) throws Exception {
67      }
68  
69  
70      /***
71       * <p>Pop the {@link MapEntriesConfig} instance from the stack,
72       * and either add it or merge it with parent information.</p>
73       *
74       * @param namespace Namespace URI of the matching element
75       * @param name Local name of the matching element
76       *
77       * @exception IllegalStateException if the popped object is not
78       *  of the correct type
79       * @exception Exception if a different error occurs
80       */
81      public void end(String namespace, String name) throws Exception {
82  
83          MapEntryConfig config = (MapEntryConfig) digester.pop();
84          MapEntriesConfig parent = (MapEntriesConfig) digester.peek();
85          MapEntryConfig previous = parent.getEntry(config.getKey());
86          if (previous == null) {
87              parent.addEntry(config);
88          } else {
89              merge(config, previous);
90          }
91  
92      }
93  
94  
95      /***
96       * <p>Merge properties from <code>config</code> into
97       * <code>previous</code>.</p>
98       *
99       * @param config Newly constructed bean
100      * @param previous Previous bean to merge into
101      */
102     static void merge(MapEntryConfig config, MapEntryConfig previous) {
103 
104         previous.setValue(config.getValue());
105 
106     }
107 
108 
109 }