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 // 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.utils; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.net.URL; import java.util.HashMap; import java.util.Map; import java.util.Properties; import java.util.Set; import org.apache.commons.io.IOUtils; import org.apache.log4j.Logger; public class PropertiesUtil { private static final Logger s_logger = Logger.getLogger(PropertiesUtil.class); /** * Searches the class path and local paths to find the config file. * @param path path to find. if it starts with / then it's absolute path. * @return File or null if not found at all. */ public static File findConfigFile(String path) { ClassLoader cl = PropertiesUtil.class.getClassLoader(); URL url = cl.getResource(path); if (url != null && "file".equals(url.getProtocol())) { return new File(url.getFile()); } url = ClassLoader.getSystemResource(path); if (url != null && "file".equals(url.getProtocol())) { return new File(url.getFile()); } File file = new File(path); if (file.exists()) { return file; } String newPath = "conf" + (path.startsWith(File.separator) ? "" : "/") + path; url = ClassLoader.getSystemResource(newPath); if (url != null && "file".equals(url.getProtocol())) { return new File(url.getFile()); } url = cl.getResource(newPath); if (url != null && "file".equals(url.getProtocol())) { return new File(url.getFile()); } newPath = "conf" + (path.startsWith(File.separator) ? "" : File.separator) + path; file = new File(newPath); if (file.exists()) { return file; } newPath = System.getProperty("catalina.home"); if (newPath == null) { newPath = System.getenv("CATALINA_HOME"); } if (newPath == null) { newPath = System.getenv("CATALINA_BASE"); } if (newPath == null) { return null; } file = new File(newPath + File.separator + "conf" + File.separator + path); if (file.exists()) { return file; } return null; } public static Map<String, Object> toMap(Properties props) { Set<String> names = props.stringPropertyNames(); HashMap<String, Object> map = new HashMap<String, Object>(names.size()); for (String name : names) { map.put(name, props.getProperty(name)); } return map; } /* * Returns an InputStream for the given resource * This is needed to read the files within a jar in classpath. */ public static InputStream openStreamFromURL(String path) { ClassLoader cl = PropertiesUtil.class.getClassLoader(); URL url = cl.getResource(path); if (url != null) { try { InputStream stream = url.openStream(); return stream; } catch (IOException ioex) { return null; } } return null; } // Returns key=value pairs by parsing a commands.properties/config file // with syntax; key=cmd;value (with this syntax cmd is stripped) and key=value public static Map<String, String> processConfigFile(String[] configFiles) { Map<String, String> configMap = new HashMap<String, String>(); Properties preProcessedCommands = new Properties(); for (String configFile : configFiles) { File commandsFile = findConfigFile(configFile); if (commandsFile != null) { try { loadFromFile(preProcessedCommands, commandsFile); } catch (FileNotFoundException fnfex) { // in case of a file within a jar in classpath, try to open stream using url InputStream stream = PropertiesUtil.openStreamFromURL(configFile); if (stream != null) { try { preProcessedCommands.load(stream); } catch (IOException e) { s_logger.error("IO Exception, unable to find properties file:", fnfex); } } else { s_logger.error("Unable to find properites file", fnfex); } } catch (IOException ioe) { s_logger.error("IO Exception loading properties file", ioe); } } } for (Object key : preProcessedCommands.keySet()) { String preProcessedCommand = preProcessedCommands.getProperty((String) key); int splitIndex = preProcessedCommand.lastIndexOf(";"); String value = preProcessedCommand.substring(splitIndex + 1); configMap.put((String) key, value); } return configMap; } /** * Load a Properties object with contents from a File. * @param properties the properties object to be loaded * @param file the file to load from * @throws IOException */ public static void loadFromFile(Properties properties, File file) throws IOException { InputStream stream = new FileInputStream(file); try { properties.load(stream); } finally { IOUtils.closeQuietly(stream); } } }