package org.apache.archiva.redback.components.cache.factory;
/*
* 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.
*/
import org.apache.archiva.redback.components.cache.Cache;
import org.apache.archiva.redback.components.cache.CacheException;
import org.apache.archiva.redback.components.cache.CacheHints;
import org.apache.archiva.redback.components.cache.impl.NoCacheCache;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.net.URL;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;
import java.util.Properties;
/**
* CacheFactory - dynamic cache creation (and tracking) facility for non-plexus objects to use.
*
* @author <a href="mailto:joakim@erdfelt.com">Joakim Erdfelt</a>
*/
public class CacheFactory
{
static class CacheFactoryHolder
{
static CacheFactory instance = new CacheFactory();
}
private static Map caches;
private static CacheCreator creator;
private Logger logger = LoggerFactory.getLogger( getClass() );
private CacheFactory()
{
caches = new HashMap();
try
{
ClassLoader classLoader = this.getClass().getClassLoader();
if ( classLoader == null )
{
classLoader = ClassLoader.getSystemClassLoader();
}
Enumeration cachePropResources = classLoader.getResources( "META-INF/plexus-cache.properties" );
if ( cachePropResources.hasMoreElements() )
{
URL propURL = (URL) cachePropResources.nextElement();
Properties props = new Properties();
props.load( propURL.openStream() );
String creatorImpl = props.getProperty( "cache.creator" );
Class creatorClass = classLoader.loadClass( creatorImpl );
creator = (CacheCreator) creatorClass.newInstance();
}
if ( cachePropResources.hasMoreElements() )
{
logger.error( "More than 1 CacheCreator provider exists in classpath. Using first one found [{}].",
creator.getClass().getName() );
}
}
catch ( IOException e )
{
throw new ExceptionInInitializerError( e );
}
catch ( ClassNotFoundException e )
{
throw new ExceptionInInitializerError( e );
}
catch ( InstantiationException e )
{
throw new ExceptionInInitializerError( e );
}
catch ( IllegalAccessException e )
{
throw new ExceptionInInitializerError( e );
}
}
public static CacheFactory getInstance()
{
return CacheFactoryHolder.instance;
}
public void setCacheCreatorFactory( CacheCreator creator )
{
CacheFactory.creator = creator;
}
public Cache getCache( String id, CacheHints hints )
throws CacheException
{
if ( creator == null )
{
return new NoCacheCache();
}
if ( caches.containsKey( id ) )
{
return (Cache) caches.get( id );
}
if ( hints == null )
{
// Setup some defaults.
hints = new CacheHints();
hints.setName( id );
}
Cache cache = CacheFactory.creator.createCache( hints );
caches.put( id, cache );
return (Cache) cache;
}
}