/**
* ================================================
* LibLoader : a free Java resource loading library
* ================================================
*
* Project Info: http://reporting.pentaho.org/libloader/
*
* (C) Copyright 2006-2008, by Pentaho Corporation and Contributors.
*
* This library is free software; you can redistribute it and/or modify it under the terms
* of the GNU Lesser General Public License as published by the Free Software Foundation;
* either version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
*
* ------------
* DefaultResourceManagerBackend.java
* ------------
*/
package org.pentaho.reporting.libraries.resourceloader;
import java.net.URL;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Map;
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;
/**
* Todo: Document Me
*
* @author Thomas Morgner
*/
public class DefaultResourceManagerBackend implements ResourceManagerBackend
{
private static Log logger = LogFactory.getLog(DefaultResourceManagerBackend.class);
private ArrayList resourceLoaders;
private ArrayList resourceBundleLoaders;
private ArrayList resourceFactories;
public DefaultResourceManagerBackend()
{
resourceLoaders = new ArrayList();
resourceBundleLoaders = new ArrayList();
resourceFactories = new ArrayList();
}
public synchronized ResourceKey createKey(final Object data, final Map parameters)
throws ResourceKeyCreationException
{
if (data == null)
{
throw new NullPointerException("Key data must not be null.");
}
final Iterator values = resourceLoaders.iterator();
while (values.hasNext())
{
final ResourceLoader loader = (ResourceLoader) values.next();
try
{
final ResourceKey key = loader.createKey(data, parameters);
if (key != null)
{
return key;
}
}
catch (ResourceKeyCreationException rkce)
{
// ignore it.
}
}
throw new ResourceKeyCreationException
("Unable to create key: No loader was able to handle the given key data: " + data);
}
/**
* Derives a new key from the given resource-key. Only keys for a hierarchical storage system (like file-systems or
* URLs) can have derived keys. Since LibLoader 0.3.0 only hierarchical keys can be derived. For that, the deriving
* path must be given as String.
* <p/>
* The optional parameter-map will be applied to the derived key after the parent's parameters have been copied to
* the new key.
* <p/>
* Before trying to derive the key, the system tries to interpret the path as absolute key-value.
*
* @param parent the parent key, or null to interpret the path as absolute key.
* @param path the relative path, that is used to derive the key.
* @param parameters a optional map containing resource-key parameters.
* @return the derived key.
* @throws ResourceKeyCreationException if deriving the key failed.
*/
public synchronized ResourceKey deriveKey(final ResourceKey parent, final String path, final Map parameters)
throws ResourceKeyCreationException
{
if (parent == null)
{
if (path == null)
{
throw new NullPointerException();
}
return createKey(path, parameters);
}
ResourceKeyCreationException rce = null;
for (int i = 0; i < resourceBundleLoaders.size(); i++)
{
final ResourceBundleLoader bundleLoader = (ResourceBundleLoader) resourceBundleLoaders.get(i);
if (bundleLoader.isSupportedKey(parent) == false)
{
continue;
}
try
{
final ResourceKey key = bundleLoader.deriveKey(parent, path, parameters);
if (key != null)
{
return key;
}
}
catch (ResourceKeyCreationException rcke)
{
rce = rcke;
}
}
// First, try to derive the resource directly. This makes sure, that we preserve the parent's context.
// If a file is derived, we assume that the result will be a file; and only if that fails we'll try to
// query the other contexts. If the parent is an URL-context, the result is assumed to be an URL as well.
for (int i = 0; i < resourceLoaders.size(); i++)
{
final ResourceLoader loader = (ResourceLoader) resourceLoaders.get(i);
if (loader.isSupportedKey(parent) == false)
{
continue;
}
try
{
final ResourceKey key = loader.deriveKey(parent, path, parameters);
if (key != null)
{
return key;
}
}
catch (ResourceKeyCreationException rcke)
{
rce = rcke;
}
}
if (path != null)
{
// Second, try to load the key as absolute value.
// This assumes, that we have no catch-all implementation.
for (int i = 0; i < resourceLoaders.size(); i++)
{
final ResourceLoader loader = (ResourceLoader) resourceLoaders.get(i);
final ResourceKey key = loader.createKey(path, parameters);
if (key != null)
{
return key;
}
}
}
final ResourceKey secondParent = parent.getParent();
if (secondParent != null)
{
// Desperate measures: Maybe the key is relative to the bundle.
for (int i = 0; i < resourceLoaders.size(); i++)
{
final ResourceLoader loader = (ResourceLoader) resourceLoaders.get(i);
if (loader.isSupportedKey(parent) == false)
{
continue;
}
try
{
final ResourceKey key = loader.deriveKey(parent, path, parameters);
if (key != null)
{
return key;
}
}
catch (ResourceKeyCreationException rcke)
{
rce = rcke;
}
}
}
if (rce != null)
{
throw rce;
}
throw new ResourceKeyCreationException
("Unable to create key: No such schema or the key was not recognized.");
}
/**
* Tries to find the first resource-loader that would be able to process the key.
*
* @param key the resource-key.
* @return the resourceloader for that key, or null, if no resource-loader is able to process the key.
*/
private ResourceLoader findBySchema(final ResourceKey key)
{
for (int i = 0; i < resourceLoaders.size(); i++)
{
final ResourceLoader loader = (ResourceLoader) resourceLoaders.get(i);
if (loader.isSupportedKey(key))
{
return loader;
}
}
return null;
}
public synchronized URL toURL(final ResourceKey key)
{
if (key == null)
{
throw new NullPointerException();
}
final ResourceLoader loader = findBySchema(key);
if (loader == null)
{
return null;
}
return loader.toURL(key);
}
public synchronized Resource create(final ResourceManager frontEnd,
final ResourceData data,
final ResourceKey context,
final Class[] target)
throws ResourceLoadingException, ResourceCreationException
{
if (frontEnd == null)
{
throw new NullPointerException();
}
if (data == null)
{
throw new NullPointerException("Data must not be null.");
}
// AutoMode ..
if (target == null)
{
return autoCreateResource(frontEnd, data, context);
}
ResourceCreationException exception = null;
final int factoryCount = resourceFactories.size();
final ResourceFactory[] factories = (ResourceFactory[])
resourceFactories.toArray(new ResourceFactory[factoryCount]);
for (int targetIdx = 0; targetIdx < target.length; targetIdx++)
{
final Class targetClass = target[targetIdx];
for (int i = 0; i < factoryCount; i++)
{
final ResourceFactory fact = factories[i];
if (isSupportedTarget(targetClass, fact) == false)
{
// Unsupported keys: Try the next factory ..
continue;
}
try
{
return fact.create(frontEnd, data, context);
}
catch (ContentNotRecognizedException ce)
{
// Ignore it, unless it is the last one.
}
catch (ResourceCreationException rex)
{
// ignore it, try the next factory ...
exception = rex;
if (logger.isDebugEnabled())
{
logger.debug("Failed at " + fact.getClass() + ": ", rex);
}
}
}
}
if (exception != null)
{
throw exception;
}
throw new ContentNotRecognizedException
("None of the selected factories was able to handle the given data: " + data.getKey());
}
private boolean isSupportedTarget(final Class target, final ResourceFactory fact)
{
final Class factoryType = fact.getFactoryType();
if (target != null && target.isAssignableFrom(factoryType))
{
return true;
}
return false;
}
private Resource autoCreateResource(final ResourceManager frontEnd,
final ResourceData data,
final ResourceKey context)
throws ResourceLoadingException, ResourceCreationException
{
final Iterator it = resourceFactories.iterator();
while (it.hasNext())
{
final ResourceFactory fact = (ResourceFactory) it.next();
try
{
final Resource res = fact.create(frontEnd, data, context);
if (res != null)
{
return res;
}
}
catch (ResourceCreationException rex)
{
// ignore it, try the next factory ...
}
}
throw new ResourceCreationException
("No known factory was able to handle the given data.");
}
public boolean isResourceUnchanged(final ResourceManager frontEnd,
final Resource resource)
throws ResourceLoadingException
{
if (frontEnd == null)
{
throw new NullPointerException();
}
if (resource == null)
{
throw new NullPointerException();
}
final ResourceKey[] deps = resource.getDependencies();
for (int i = 0; i < deps.length; i++)
{
final ResourceKey dep = deps[i];
final long version = resource.getVersion(dep);
if (version == -1)
{
// non-versioning key, ignore it.
continue;
}
final ResourceData data = frontEnd.load(dep);
if (data.getVersion(frontEnd) != version)
{
// oh, my bad, an outdated or changed entry.
// We have to re-read the whole thing.
return false;
}
}
// all versions have been confirmed to be valid. Nice, we can use the
// cached product.
return true;
}
/**
* Tries to find the first resource-bundle-loader that would be able to process the key.
*
* @param key the resource-key.
* @return the resourceloader for that key, or null, if no resource-loader is able to process the key.
* @throws ResourceLoadingException if an error occured.
*/
public synchronized ResourceBundleData loadResourceBundle(final ResourceManager frontEnd,
final ResourceKey key) throws ResourceLoadingException
{
if (frontEnd == null)
{
throw new NullPointerException();
}
if (key == null)
{
throw new NullPointerException();
}
for (int i = 0; i < resourceBundleLoaders.size(); i++)
{
final ResourceBundleLoader loader = (ResourceBundleLoader) resourceBundleLoaders.get(i);
final ResourceBundleData resourceBundle = loader.loadBundle(frontEnd, key);
if (resourceBundle != null)
{
return resourceBundle;
}
}
return null;
}
public ResourceData loadRawData(final ResourceManager frontEnd, final ResourceKey key) throws ResourceLoadingException, UnrecognizedLoaderException
{
if (frontEnd == null)
{
throw new NullPointerException();
}
if (key == null)
{
throw new NullPointerException();
}
final ResourceLoader loader = findBySchema(key);
if (loader == null)
{
throw new UnrecognizedLoaderException("Invalid key: No resource-loader registered for schema: " + key.getSchema());
}
logger.debug("Loaded " + key);
return loader.load(key);
}
public void registerDefaultFactories()
{
final Configuration config = LibLoaderBoot.getInstance().getGlobalConfig();
final Iterator itType = config.findPropertyKeys(ResourceManager.FACTORY_TYPE_PREFIX);
while (itType.hasNext())
{
final String key = (String) itType.next();
final String factoryClass = config.getConfigProperty(key);
final Object maybeFactory = ObjectUtilities.loadAndInstantiate
(factoryClass, ResourceManager.class, ResourceFactory.class);
if (maybeFactory instanceof ResourceFactory == false)
{
continue;
}
final ResourceFactory factory = (ResourceFactory) maybeFactory;
factory.initializeDefaults();
registerFactory(factory);
}
}
public void registerDefaultLoaders()
{
final Configuration config = LibLoaderBoot.getInstance().getGlobalConfig();
final Iterator it = config.findPropertyKeys(ResourceManager.LOADER_PREFIX);
while (it.hasNext())
{
final String key = (String) it.next();
final String value = config.getConfigProperty(key);
final ResourceLoader loader = (ResourceLoader)
ObjectUtilities.loadAndInstantiate(value, ResourceManager.class, ResourceLoader.class);
if (loader != null)
{
//Log.debug("Registering loader for " + loader.getSchema());
registerLoader(loader);
}
}
final Iterator bit = config.findPropertyKeys(ResourceManager.BUNDLE_LOADER_PREFIX);
while (bit.hasNext())
{
final String key = (String) bit.next();
final String value = config.getConfigProperty(key);
final ResourceBundleLoader loader = (ResourceBundleLoader)
ObjectUtilities.loadAndInstantiate(value, ResourceManager.class, ResourceBundleLoader.class);
if (loader != null)
{
//Log.debug("Registering loader for " + loader.getSchema());
registerBundleLoader(loader);
}
}
}
public void registerBundleLoader(final ResourceBundleLoader loader)
{
if (loader == null)
{
throw new NullPointerException("ResourceLoader must not be null.");
}
resourceBundleLoaders.add(loader);
}
public void registerLoader(final ResourceLoader loader)
{
if (loader == null)
{
throw new NullPointerException("ResourceLoader must not be null.");
}
resourceLoaders.add(loader);
}
public void registerFactory(final ResourceFactory factory)
{
if (factory == null)
{
throw new NullPointerException("ResourceFactory must not be null.");
}
resourceFactories.add(factory);
}
}