/*
* 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 org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.pentaho.reporting.libraries.base.config.Configuration;
import org.pentaho.reporting.libraries.base.util.ObjectUtilities;
import org.pentaho.reporting.libraries.resourceloader.ContentNotRecognizedException;
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.ResourceKey;
import org.pentaho.reporting.libraries.resourceloader.ResourceLoadingException;
import org.pentaho.reporting.libraries.resourceloader.ResourceManager;
import java.util.HashSet;
import java.util.Iterator;
import java.util.TreeSet;
/**
* 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>
* <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." );
}
}