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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  
18  package org.apache.commons.configuration.reloading;
19  
20  import org.apache.commons.configuration.FileConfiguration;
21  import org.apache.commons.logging.Log;
22  import org.apache.commons.logging.LogFactory;
23  
24  /***
25   * A strategy to reload configuration based on management requests. Designed for
26   * JMX management.
27   *
28   * @author Nicolas De loof
29   */
30  public class ManagedReloadingStrategy implements ReloadingStrategy,
31          ManagedReloadingStrategyMBean
32  {
33      /*** The logger. */
34      private Log log = LogFactory.getLog(ManagedReloadingStrategy.class);
35  
36      /*** Stores a reference to the associated configuration. */
37      private FileConfiguration configuration;
38  
39      /*** A flag whether a reload is required. */
40      private boolean reloadingRequired;
41  
42      /***
43       * @see org.apache.commons.configuration.reloading.ReloadingStrategy#init()
44       */
45      public void init()
46      {
47          return;
48      }
49  
50      /***
51       * @see org.apache.commons.configuration.reloading.ReloadingStrategy#reloadingPerformed()
52       */
53      public void reloadingPerformed()
54      {
55          reloadingRequired = false;
56      }
57  
58      /***
59       * Checks whether reloading is required. This implementation checks whether
60       * the <code>refresh()</code> method has been invokded.
61       *
62       * @return a flag whether reloading is required
63       * @see org.apache.commons.configuration.reloading.ReloadingStrategy#reloadingRequired()
64       */
65      public boolean reloadingRequired()
66      {
67          return reloadingRequired;
68      }
69  
70      /***
71       * Sets the associated configuration.
72       *
73       * @param configuration the associated configuration
74       */
75      public void setConfiguration(FileConfiguration configuration)
76      {
77          this.configuration = configuration;
78      }
79  
80      /***
81       * Tells this strategy that the monitored configuration file should be
82       * refreshed. This method will typically be called from outside (through an
83       * exposed MBean) on behalf of an administrator.
84       *
85       * @see org.apache.commons.configuration.reloading.ManagedReloadingStrategyMBean#refresh()
86       */
87      public void refresh()
88      {
89          log.info("Reloading configuration.");
90          this.reloadingRequired = true;
91          // force reloading
92          configuration.isEmpty();
93      }
94  }