/* * Distributed as part of c3p0 v.0.9.1-pre6 * * Copyright (C) 2005 Machinery For Change, Inc. * * Author: Steve Waldman <swaldman@mchange.com> * * This library is free software; you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License version 2.1, as  * published by the Free Software Foundation. * * This software 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. * * You should have received a copy of the GNU Lesser General Public License * along with this software; see the file LICENSE.  If not, write to the * Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307, USA. */package com.mchange.v2.cfg;import java.util.*;import java.io.*;import com.mchange.v2.log.*;/** * MultiPropertiesConfig allows applications to accept configuration data * from a more than one property file (each of which is to be loaded from * a unique path using this class' ClassLoader's resource-loading mechanism), * and permits access to property data via the resource path from which the * properties were loaded, via the prefix of the property (where hierarchical  * property names are presumed to be '.'-separated), and simply by key. * In the by-key and by-prefix indices, when two definitions conflict, the * key value pairing specified in the MOST RECENT properties file shadows * earlier definitions, and files are loaded in the order of the list of * resource paths provided a constructor. * * The rescource path "/" is a special case that always refers to System * properties. No actual resource will be loaded. * The class manages a special instance called "vmConfig" which is accessable * via a static method. It's resource path is list specified by a text-file, * itself a ClassLoader managed resource, which must be located at * <tt>/com/mchange/v2/cfg/vmConfigResourcePaths.txt</tt>. This file should * be one resource path per line, with blank lines ignored and lines beginning * with '#' treated as comments. */public abstract class MultiPropertiesConfig{    final static MultiPropertiesConfig EMPTY = new BasicMultiPropertiesConfig( new String[0] );    final static String VM_CONFIG_RSRC_PATHS = "/com/mchange/v2/cfg/vmConfigResourcePaths.txt";    static MultiPropertiesConfig vmConfig = null;    public static MultiPropertiesConfig read(String[] resourcePath, MLogger logger)    { return new BasicMultiPropertiesConfig( resourcePath, logger ); }    public static MultiPropertiesConfig read(String[] resourcePath)    { return new BasicMultiPropertiesConfig( resourcePath ); }    public static MultiPropertiesConfig combine( MultiPropertiesConfig[] configs )    { return new CombinedMultiPropertiesConfig( configs ); }    public static MultiPropertiesConfig readVmConfig(String[] defaultResources, String[] preemptingResources)    {	List l = new LinkedList();	if (defaultResources != null)	    l.add( read( defaultResources ) );	l.add( readVmConfig() );	if (preemptingResources != null)	    l.add( read( preemptingResources ) );	return combine( (MultiPropertiesConfig[]) l.toArray( new MultiPropertiesConfig[ l.size() ] ) );    }    public static MultiPropertiesConfig readVmConfig()    {	if ( vmConfig == null )	    {		List rps = new ArrayList();		BufferedReader br = null;		try		    {			InputStream is = MultiPropertiesConfig.class.getResourceAsStream( VM_CONFIG_RSRC_PATHS );			if ( is != null )			    {				br = new BufferedReader( new InputStreamReader( is, "8859_1" ) );				String rp;				while ((rp = br.readLine()) != null)				    {					rp = rp.trim();					if ("".equals( rp ) || rp.startsWith("#"))					    continue;										rps.add( rp );				    }				vmConfig = new BasicMultiPropertiesConfig( (String[]) rps.toArray( new String[ rps.size() ] ) ); 			    }			else			    {				//System.err.println("Resource path list could not be found at resource path: " + VM_CONFIG_RSRC_PATHS);				//System.err.println("Using empty vmconfig.");				vmConfig = EMPTY;			    }		    }		catch (IOException e)		    { e.printStackTrace(); }		finally		    {			try { if ( br != null ) br.close(); }			catch (IOException e) { e.printStackTrace(); }		    }	    }	return vmConfig;    }    public boolean foundVmConfig()    { return vmConfig != EMPTY; }    public abstract String[] getPropertiesResourcePaths();    public abstract Properties getPropertiesByResourcePath(String path);    public abstract Properties getPropertiesByPrefix(String pfx);    public abstract String getProperty( String key );}