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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.log4j.chainsaw;
18  
19  import java.io.File;
20  import java.io.FileReader;
21  import java.io.FileWriter;
22  
23  import com.thoughtworks.xstream.XStream;
24  import com.thoughtworks.xstream.io.xml.DomDriver;
25  
26  import org.apache.log4j.chainsaw.prefs.LoadSettingsEvent;
27  import org.apache.log4j.chainsaw.prefs.SaveSettingsEvent;
28  import org.apache.log4j.chainsaw.prefs.SettingsListener;
29  import org.apache.log4j.chainsaw.prefs.SettingsManager;
30  
31  /**
32   * Helper class that helps delegate the work of loading and saving the  values
33   * of the ApplicationPreferenceModel, allowing that class to remain a simple
34   * bean.
35   * 
36   * The Model passed to this class' constructor is the instance of the ApplicationPreference
37   * that will be saved, and will have properties modified by loading from the
38   * 'chainsaw.settings.xml' file in the .chainsaw directory of the user's home directory.
39   * 
40   * @author psmith
41   *
42   */
43  public class ApplicationPreferenceModelSaver implements SettingsListener {
44  
45      private final ApplicationPreferenceModel model;
46      
47      /**
48       * @param model
49       */
50      public ApplicationPreferenceModelSaver(final ApplicationPreferenceModel model) {
51          this.model = model;
52      }
53  
54      public void loadSettings(LoadSettingsEvent event) {
55          XStream stream = new XStream(new DomDriver());
56          File file = getApplicationPreferenceXMLFile(SettingsManager.getInstance().getSettingsDirectory());
57          try {
58              if (file.exists()) {
59                  FileReader reader = new FileReader(file);
60                  ApplicationPreferenceModel loadedModel = (ApplicationPreferenceModel) stream
61                          .fromXML(reader);
62                  model.apply(loadedModel);
63                  reader.close();
64              }
65          } catch (Exception e) {
66  //            TODO exception handling
67              e.printStackTrace();
68              //unable to process - delete file 
69              file.delete();
70          }
71      }
72  
73      public void saveSettings(SaveSettingsEvent event) {
74          XStream stream = new XStream(new DomDriver());
75          try {
76              File file = getApplicationPreferenceXMLFile(event.getSettingsLocation());
77              FileWriter writer = new FileWriter(file);
78              stream.toXML(model, writer);
79              writer.close();
80          } catch (Exception e) {
81  //            TODO exception handling
82              e.printStackTrace();
83          }
84  
85      }
86  
87      private File getApplicationPreferenceXMLFile(File settingsLocation) {
88          return new File(settingsLocation, "chainsaw.settings.xml");
89      }
90  
91  }