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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  package org.apache.jetspeed.security.impl;
18  
19  import java.util.ArrayList;
20  import java.util.List;
21  import java.util.prefs.BackingStoreException;
22  import java.util.prefs.Preferences;
23  
24  import org.apache.commons.logging.Log;
25  import org.apache.commons.logging.LogFactory;
26  import org.apache.jetspeed.util.ArgUtil;
27  
28  /***
29   * <p>
30   * Base implementation for the hierarchy resolver.
31   * <p>
32   * 
33   * @author <a href="mailto:dlestrat@apache.org">David Le Strat</a>
34   */
35  public class BaseHierarchyResolver
36  {
37      /*** The logger. */
38      private static final Log log = LogFactory.getLog(BaseHierarchyResolver.class);
39      
40      /***
41       * @see org.apache.jetspeed.security.HierarchyResolver#resolveChildren(java.util.prefs.Preferences)
42       */
43      public String[] resolveChildren(Preferences prefs)
44      {
45          ArgUtil.notNull(new Object[] { prefs }, new String[] { "preferences" }, "resolveChildren(java.util.prefs.Preferences)");
46  
47          List children = new ArrayList();
48          processPreferences(prefs, children);
49          return (String[]) children.toArray(new String[0]);
50      }
51      
52      /***
53       * <p>
54       * Recursively processes the preferences.
55       * </p>
56       * 
57       * @param prefs The preferences.
58       * @param list The list to add the preferences to.
59       */
60      protected void processPreferences(Preferences prefs, List list)
61      {
62          if (!list.contains(prefs.absolutePath()))
63          {
64              list.add(prefs.absolutePath());
65          }
66          try
67          {
68              String[] names = prefs.childrenNames();
69              for (int i = 0; i < names.length; i++)
70              {
71                  processPreferences(prefs.node(names[i]), list);
72              }
73          }
74          catch (BackingStoreException bse)
75          {
76              log.warn("can't find children of " + prefs.absolutePath(), bse);
77          }
78      }
79  }