net.sf.staccatocommons.io.preferences.CharSerializationObjectPreferences Maven / Gradle / Ivy

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/**
 *  Copyright (c) 2010-2012, The StaccatoCommons Team
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU Lesser General Public License as published by
 *  the Free Software Foundation; version 3 of the License.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser General Public License for more details.
 */

package net.sf.staccatocommons.io.preferences;

import java.util.prefs.BackingStoreException;
import java.util.prefs.Preferences;

import net.sf.staccatocommons.io.serialization.CharSerializationManager;
import net.sf.staccatocommons.restrictions.check.NonNull;

import org.apache.commons.lang.SerializationException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * {@link ObjectPreferences} implementation that serializes objects using a
 * {@link CharSerializationManager}
 * 
 * @author flbulgarelli
 */
public class CharSerializationObjectPreferences implements ObjectPreferences {

  private static final Logger LOG = LoggerFactory.getLogger(CharSerializationObjectPreferences.class);

  private final Preferences preferences;
  private final CharSerializationManager serializationManager;

  /**
   * Creates a new {@link CharSerializationObjectPreferences}
   * 
   * @param preferences
   *          non null.
   * @param stream
   *          non null.
   */
  public CharSerializationObjectPreferences(@NonNull Preferences preferences, @NonNull CharSerializationManager stream) {
    this.preferences = preferences;
    this.serializationManager = stream;
  }

  @NonNull
  public Preferences getNode() {
    return preferences;
  }

  public void put(@NonNull String key, Object value) {
    preferences.put(key, serializationManager.serialize(value));
  }

  public  T get(@NonNull String key, T defaultValue) {
    String valueAsString = preferences.get(key, null);
    if (valueAsString == null) {
      LOG.debug("Preference " + key + "not found. Loading defaults");
      return defaultValue;
    }
    try {
      return (T) serializationManager.deserialize(valueAsString);
    } catch (SerializationException e) {
      LOG.warn("Could not read valid value for preference " + key + ", loading defaults " + defaultValue);
      LOG.debug("Loading preference " + key + "threw an exception", e);
      return defaultValue;
    }
  }

  public void flush() throws BackingStoreException {
    preferences.flush();
  }

  public void sync() throws BackingStoreException {
    preferences.sync();
  }

  public void remove(String key) {
    preferences.remove(key);
  }

  /**
   * Answers an user node {@link ObjectPreferences} for the given class package
   * 
   * @param clazz
   * @param serializarionManager
   *          the {@link CharSerializationManager} to deserialize and serialize
   *          the objects
   * @return a new {@link ObjectPreferences}
   */
  public static ObjectPreferences userNodeForPackage(@NonNull Class clazz,
    @NonNull CharSerializationManager serializarionManager) {
    return new CharSerializationObjectPreferences(Preferences.userNodeForPackage(clazz), serializarionManager);
  }

  /**
   * Answers a system node {@link ObjectPreferences} for the given class package
   * 
   * @param clazz
   * @param serializarionManager
   *          the {@link CharSerializationManager} to deserialize and serialize
   *          the objects
   * @return a new {@link ObjectPreferences}
   */
  public static ObjectPreferences systemNodeForPackage(Class clazz, CharSerializationManager serializarionManager) {
    return new CharSerializationObjectPreferences(Preferences.systemNodeForPackage(clazz), serializarionManager);
  }

}