winery/org.eclipse.winery.repository/src/main/java/org/eclipse/winery/repository/backend/filebased/AutoSaveListener.java

   1 /*******************************************************************************
   2  * Copyright (c) 2012-2013 University of Stuttgart.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Eclipse Public License v1.0
   5  * and the Apache License 2.0 which both accompany this distribution,
   6  * and are available at http://www.eclipse.org/legal/epl-v10.html
   7  * and http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Contributors:
  10  *     Oliver Kopp - initial API and implementation
  11  *******************************************************************************/
  12 package org.eclipse.winery.repository.backend.filebased;
  13
  14 import java.io.IOException;
  15 import java.io.OutputStream;
  16 import java.io.OutputStreamWriter;
  17 import java.nio.file.Files;
  18 import java.nio.file.Path;
  19 import java.nio.file.StandardOpenOption;
  20
  21 import org.apache.commons.configuration.ConfigurationException;
  22 import org.apache.commons.configuration.PropertiesConfiguration;
  23 import org.apache.commons.configuration.event.ConfigurationEvent;
  24 import org.apache.commons.configuration.event.ConfigurationListener;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27
  28 /**
  29  * We do not count loads and saves as in
  30  * {@link org.apache.commons.configuration.builder.AutoSaveListener}, because
  31  * ConfigurationListener is not aware of such things
  32  */
  33 class AutoSaveListener implements ConfigurationListener {
  34
  35         private static final Logger logger = LoggerFactory.getLogger(AutoSaveListener.class);
  36
  37         private final Path path;
  38         private final PropertiesConfiguration configuration;
  39
  40
  41         /**
  42          *
  43          * @param path the file path to write to
  44          * @param configuration the configuration, where the change events come
  45          *            from. This is needed as <code>event.getSource()</code> does
  46          *            not work
  47          */
  48         public AutoSaveListener(Path path, PropertiesConfiguration configuration) {
  49                 this.path = path;
  50                 this.configuration = configuration;
  51         }
  52
  53         @Override
  54         public void configurationChanged(ConfigurationEvent event) {
  55                 if (!event.isBeforeUpdate()) {
  56                         try {
  57                                 if (!Files.exists(this.path.getParent())) {
  58                                         Files.createDirectories(this.path.getParent());
  59                                 }
  60                         } catch (IOException ce) {
  61                                 AutoSaveListener.logger.error("Could not update properties file", ce);
  62                                 return;
  63                         }
  64                         try (OutputStream out = Files.newOutputStream(this.path, StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING)) {
  65                                 OutputStreamWriter writer = new OutputStreamWriter(out);
  66                                 this.configuration.save(writer);
  67                         } catch (ConfigurationException | IOException ce) {
  68                                 AutoSaveListener.logger.error("Could not update properties file", ce);
  69                         }
  70                 }
  71         }
  72 }