Java tutorial
// 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 javax.ejb.Local; import org.apache.commons.io.IOUtils; import org.apache.log4j.Logger; 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 || * } **/ @Local(value = { StorageComponent.class }) public class PropertiesStorage implements StorageComponent { private static final Logger s_logger = Logger.getLogger(PropertiesStorage.class); 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) { _properties.setProperty(key, value); FileOutputStream output = null; try { output = new FileOutputStream(_file); _properties.store(output, _name); output.flush(); output.close(); } catch (IOException e) { s_logger.error("Uh-oh: ", e); } finally { IOUtils.closeQuietly(output); } } @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()) { s_logger.error("Unable to create _file: " + file.getAbsolutePath()); return false; } } catch (IOException e) { s_logger.error("Unable to create _file: " + file.getAbsolutePath(), e); return false; } } try { PropertiesUtil.loadFromFile(_properties, file); _file = file; } catch (FileNotFoundException e) { s_logger.error("How did we get here? ", e); return false; } catch (IOException e) { s_logger.error("IOException: ", e); return false; } return true; } @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 } }