content: // Licensed to the Apache Software Foundation (ASF) under one
  // or more contributor license agreements.  See the NOTICE file
  // distributed with this work for additional information
  // regarding copyright ownership.  The ASF licenses this file
  // to you under the Apache License, Version 2.0 (the
  // "License"); you may not use this file except in compliance
  // with the License.  You may obtain a copy of the License at
  //
  //   http://www.apache.org/licenses/LICENSE-2.0
  //
  // Unless required by applicable law or agreed to in writing,
  // software distributed under the License is distributed on an
  // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, either express or implied.  See the License for the
  // specific language governing permissions and limitations
  // under the License.
  package com.cloud.agent.dao.impl;
  
  import java.io.File;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.util.Map;
  import java.util.Properties;
  
  import org.apache.commons.io.IOUtils;
  import org.apache.logging.log4j.Logger;
  import org.apache.logging.log4j.LogManager;
  
  import com.cloud.agent.dao.StorageComponent;
  import com.cloud.utils.PropertiesUtil;
  
  /**
   * Uses Properties to implement storage.
   *
   * @config {@table || Param Name | Description | Values | Default || || path |
   *         path to the properties _file | String | db/db.properties || * }
   **/
  public class PropertiesStorage implements StorageComponent {
      protected Logger logger = LogManager.getLogger(getClass());
      Properties _properties = new Properties();
      File _file;
      String _name;
  
      @Override
      public synchronized String get(String key) {
          return _properties.getProperty(key);
      }
  
      @Override
      public synchronized void persist(String key, String value) {
          if (!loadFromFile(_file)) {
              logger.error("Failed to load changes and then write to them");
          }
          _properties.setProperty(key, value);
          FileOutputStream output = null;
          try {
              output = new FileOutputStream(_file);
              _properties.store(output, _name);
              output.flush();
              output.close();
          } catch (IOException e) {
              logger.error("Uh-oh: ", e);
          } finally {
              IOUtils.closeQuietly(output);
          }
      }
  
      private synchronized boolean loadFromFile(final File file) {
          try {
              PropertiesUtil.loadFromFile(_properties, file);
              _file = file;
          } catch (FileNotFoundException e) {
              logger.error("How did we get here? ", e);
              return false;
          } catch (IOException e) {
              logger.error("IOException: ", e);
              return false;
          }
          return true;
      }
  
      @Override
      public synchronized boolean configure(String name, Map<String, Object> params) {
          _name = name;
          String path = (String)params.get("path");
          if (path == null) {
              path = "agent.properties";
          }
  
          File file = PropertiesUtil.findConfigFile(path);
          if (file == null) {
              file = new File(path);
              try {
                  if (!file.createNewFile()) {
                      logger.error("Unable to create _file: {}", file.getAbsolutePath());
                      return false;
                  }
              } catch (IOException e) {
                  logger.error("Unable to create file: {}", file.getAbsolutePath());
                  logger.debug("IOException while trying to create file: {}", file.getAbsolutePath(), e);
                  return false;
              }
          }
          return loadFromFile(file);
      }
  
      @Override
      public synchronized String getName() {
          return _name;
      }
  
      @Override
      public boolean start() {
          return true;
      }
  
      @Override
      public boolean stop() {
          return true;
      }
  
      @Override
      public void setName(String name) {
          // TODO Auto-generated method stub
  
      }
  
      @Override
      public void setConfigParams(Map<String, Object> params) {
          // TODO Auto-generated method stub
  
      }
  
      @Override
      public Map<String, Object> getConfigParams() {
          // TODO Auto-generated method stub
          return null;
      }
  
      @Override
      public int getRunLevel() {
          // TODO Auto-generated method stub
          return 0;
      }
  
      @Override
      public void setRunLevel(int level) {
          // TODO Auto-generated method stub
      }
  
  }
  