/*
* This program 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.
*
* You should have received a copy of the GNU Lesser General Public License along with this
* program; if not, you can obtain a copy at http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* or from the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* This program 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.
*
* Copyright (c) 2006 - 2013 Pentaho Corporation and Contributors. All rights reserved.
*/
package org.pentaho.reporting.libraries.resourceloader.factory;
import java.util.HashSet;
import java.util.Iterator;
import java.util.TreeSet;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.reporting.libraries.resourceloader.LibLoaderBoot;
import org.pentaho.reporting.libraries.resourceloader.Resource;
import org.pentaho.reporting.libraries.resourceloader.ResourceCreationException;
import org.pentaho.reporting.libraries.resourceloader.ResourceData;
import org.pentaho.reporting.libraries.resourceloader.ResourceFactory;
import org.pentaho.reporting.libraries.resourceloader.ResourceLoadingException;
import org.pentaho.reporting.libraries.resourceloader.ResourceKey;
import org.pentaho.reporting.libraries.resourceloader.ResourceManager;
import org.pentaho.reporting.libraries.resourceloader.ContentNotRecognizedException;
import org.pentaho.reporting.libraries.base.util.ObjectUtilities;
import org.pentaho.reporting.libraries.base.config.Configuration;
/**
* Creation-Date: 05.04.2006, 16:58:57
*
* @author Thomas Morgner
*/
public abstract class AbstractResourceFactory implements ResourceFactory
{
private static Log logger = LogFactory.getLog(AbstractResourceFactory.class);
private static class ResourceFactoryEntry implements Comparable
{
private FactoryModule module;
private int weight;
private ResourceFactoryEntry(final FactoryModule module, final int weight)
{
this.module = module;
this.weight = weight;
}
public FactoryModule getModule()
{
return module;
}
public int getWeight()
{
return weight;
}
public boolean equals(final Object o)
{
if (this == o)
{
return true;
}
if (o == null || getClass() != o.getClass())
{
return false;
}
final ResourceFactoryEntry that = (ResourceFactoryEntry) o;
if (weight != that.weight)
{
return false;
}
if (module != null ? !module.equals(that.module) : that.module != null)
{
return false;
}
return true;
}
public int hashCode()
{
int result;
result = (module != null ? module.hashCode() : 0);
result = 31 * result + weight;
return result;
}
/**
* Compares this object with the specified object for order. Returns a
* negative integer, zero, or a positive integer as this object is less than,
* equal to, or greater than the specified object.<p>
*
* "Note: this class has a natural ordering that is inconsistent with
* equals."
*
* @param o the Object to be compared.
* @return a negative integer, zero, or a positive integer as this object is
* less than, equal to, or greater than the specified object.
* @throws ClassCastException if the specified object's type prevents it from
* being compared to this Object.
*/
public int compareTo(final Object o)
{
final ResourceFactoryEntry entry = (ResourceFactoryEntry) o;
// the order is intentionally reveresed, so that a sorted set has the best
// fit as first entry.
if (weight == entry.weight)
{
return 0;
}
if (weight < entry.weight)
{
return -1;
}
return 1;
}
}
/** The available factory methods. */
private HashSet<FactoryModule> factoryModules;
/** Which type of objects do we create here? */
private Class factoryType;
protected AbstractResourceFactory(final Class factoryType)
{
if (factoryType == null)
{
throw new NullPointerException();
}
this.factoryType = factoryType;
this.factoryModules = new HashSet<FactoryModule>();
}
public Class getFactoryType()
{
return factoryType;
}
public void initializeDefaults ()
{
final String type = getFactoryType().getName();
final String prefix = CONFIG_PREFIX + type;
final Configuration config = LibLoaderBoot.getInstance().getGlobalConfig();
final Iterator itType = config.findPropertyKeys(prefix);
while (itType.hasNext())
{
final String key = (String) itType.next();
final String modClass = config.getConfigProperty(key);
final FactoryModule maybeFactory = ObjectUtilities.loadAndInstantiate
(modClass, AbstractResourceFactory.class, FactoryModule.class);
if (maybeFactory == null)
{
continue;
}
registerModule(maybeFactory);
}
}
public synchronized boolean registerModule(final String className)
{
try
{
final ClassLoader loader = ObjectUtilities.getClassLoader(getClass());
final Class c = Class.forName(className, false, loader);
registerModule((FactoryModule) c.newInstance());
return true;
}
catch (Exception e)
{
return false;
}
}
public synchronized void registerModule(final FactoryModule module)
{
if (factoryModules.contains(module))
{
return;
}
factoryModules.add(module);
}
/**
*
* @param data
* @param context
* @return
* @throws ResourceCreationException
* @throws ResourceLoadingException
*/
public synchronized Resource create(final ResourceManager manager,
final ResourceData data,
final ResourceKey context)
throws ResourceCreationException, ResourceLoadingException
{
final TreeSet<ResourceFactoryEntry> sortedEntries = new TreeSet<ResourceFactoryEntry>();
final Iterator<FactoryModule> factoryModulesIt = factoryModules.iterator();
while (factoryModulesIt.hasNext())
{
final FactoryModule mod = factoryModulesIt.next();
final int weight = mod.canHandleResource(manager, data);
if (weight >= 0)
{
sortedEntries.add(new ResourceFactoryEntry(mod, weight));
}
}
final Iterator<ResourceFactoryEntry> it = sortedEntries.iterator();
while (it.hasNext())
{
final ResourceFactoryEntry entry = it.next();
try
{
return entry.getModule().create(manager, data, context);
}
catch (ResourceCreationException ex)
{
if (ex instanceof ContentNotRecognizedException)
{
throw ex;
}
}
catch(Exception ex)
{
// ok, that one failed, try the next one ...
if (logger.isDebugEnabled())
{
logger.debug("Failed to load content with module " + entry.getModule() + ":", ex);
}
}
}
throw new ContentNotRecognizedException("No valid handler for the given content.");
}
}