// Copyright (c) 2000 Just Objects B.V. <just@justobjects.nl>// Distributable under LGPL license. See terms of license at gnu.org.package nl.justobjects.pushlet.core;import nl.justobjects.pushlet.util.Log;import nl.justobjects.pushlet.util.PushletException;import nl.justobjects.pushlet.util.Sys;import java.io.File;import java.util.Properties;/** * Loads and maintains overall configuration. * * @author Just van den Broecke - Just Objects &copy; * @version $Id: Config.java,v 1.5 2007/11/23 21:10:17 justb Exp $ */public class Config implements ConfigDefs {	private static final String PROPERTIES_FILE = "pushlet.properties";	private static Properties properties;	/**	 * Factory method: create object from property denoting class name.	 *	 * @param aClassNameProp property name e.g. "session.class"	 * @return an instance of class denoted by property	 * @throws PushletException when class cannot be instantiated	 */	public static Object createObject(String aClassNameProp, String aDefault) throws PushletException {		Class clazz = getClass(aClassNameProp, aDefault);		try {			return clazz.newInstance();		} catch (Throwable t) {			// Usually a misconfiguration			throw new PushletException("Cannot instantiate class for " + aClassNameProp + "=" + clazz, t);		}	}	/**	 * Factory method: create object from property denoting class name.	 *	 * @param aClassNameProp property name e.g. "session.class"	 * @return a Class object denoted by property	 * @throws PushletException when class cannot be instantiated	 */	public static Class getClass(String aClassNameProp, String aDefault) throws PushletException {		// Singleton + factory pattern:  create object instance		// from configured class name		String clazz = (aDefault == null ? getProperty(aClassNameProp) : getProperty(aClassNameProp, aDefault));		try {			return Class.forName(clazz);		} catch (ClassNotFoundException t) {			// Usually a misconfiguration			throw new PushletException("Cannot find class for " + aClassNameProp + "=" + clazz, t);		}	}	/**	 * Initialize event sources from properties file.	 */	public static void load(String aDirPath) {		// Load Event sources using properties file.		try {			// Try loading through classpath first (e.g. in WEB-INF/classes or from .jar)			Log.info("Config: loading " + PROPERTIES_FILE + " from classpath");			properties = Sys.loadPropertiesResource(PROPERTIES_FILE);		} catch (Throwable t) {			// Try from provided dir (e.g. WEB_INF/pushlet.properties)			String filePath = aDirPath + File.separator + PROPERTIES_FILE;			System.out.println("Config: cannot load " + PROPERTIES_FILE + " from classpath, will try from ");			Log.info("Config: cannot load " + PROPERTIES_FILE + " from classpath, will try from " + filePath);			try {				properties = Sys.loadPropertiesFile(filePath);			} catch (Throwable t2) {				Log.fatal("Config: cannot load properties file from " + filePath, t);				// Give up				return;			}		}		Log.debug("Config: loaded values=" + properties);	}	public static String getProperty(String aName, String aDefault) {		return properties.getProperty(aName, aDefault);	}	public static String getProperty(String aName) {		String value = properties.getProperty(aName);		if (value == null) {			throw new IllegalArgumentException("Unknown property: " + aName);		}		return value;	}	public static boolean getBoolProperty(String aName) {		String value = getProperty(aName);		try {			return value.equals("true");		} catch (Throwable t) {			throw new IllegalArgumentException("Illegal property value: " + aName + " val=" + value);		}	}	public static int getIntProperty(String aName) {		String value = getProperty(aName);		try {			return Integer.parseInt(value);		} catch (Throwable t) {			throw new IllegalArgumentException("Illegal property value: " + aName + " val=" + value);		}	}	public static long getLongProperty(String aName) {		String value = getProperty(aName);		try {			return Long.parseLong(value);		} catch (Throwable t) {			throw new IllegalArgumentException("Illegal property value: " + aName + " val=" + value);		}	}	public static boolean hasProperty(String aName) {		return properties.containsKey(aName);	}}/* * $Log: Config.java,v $ * Revision 1.5  2007/11/23 21:10:17  justb * add hooks for custom logging (you can override DefaultLogger in pushlet.properties) * * Revision 1.4  2007/11/23 14:33:07  justb * core classes now configurable through factory * * Revision 1.3  2007/11/10 13:44:02  justb * pushlet.properties and sources.properties can now also be put under WEB-INF * * Revision 1.2  2006/05/06 00:10:11  justb * various chgs but not too serious... * * Revision 1.1  2005/02/18 12:36:47  justb * changes for renaming and configurability * * */